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Mandibular First Molar

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					Permanent Mandibular Molars




       Charles J. Arcoria, DDS, MBA
Mandibular First Molar
Calcification and Eruption
  Calcification   begins……………….Birth

  Crown   completed………………….3 years

  Eruption……………………………….6          years

  Root   completed…………………….9 years
Mandibular First Molar
Key Points
    5 cusps/5 lobes
        Mesiofacial
        Mesiolingual
        Distolingual
        Distofacial
        Distal- smallest
Naming the Grooves of the Mandibular First Molar



   Central groove
       “M” or “W”
   Mesiofacial groove
       Prominent pit at
        termination
 Distofacial groove
 Lingual groove
 2 triangular fossae,
  1 central fossa
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are
    more rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is
    almost flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet
    more at an angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small
    part of the total mesiodistal width of the facial surface because most of the cusp is lingual to the
    distofacial line angle placing it on the distal aspect of the tooth. The distal cusp is also very rounded
    occlusally but more pointed than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the
    mesiofacial and the distofacial cusps. The distofacial groove separates the distofacial and distal
    cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary
    restorations.
                                                                                                                        D
   The facial cervical ridge occupies the area cervical to the lateral depression described above for
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown


    surface of the tooth.
    The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
                                                                                                                            M
    longer and more divergent than those of the mandibular second or third molar.
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial
    surface and terminates about half way to the cervical line. It often ends in a slight depression that
    extends laterally from the terminus of the groove. Also, there is often a pit present at the terminus
    that frequently requires restoration. Clinically these are termed “facial” or “buccal” pits that are


    considered simple yet necessary restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical
    1/3 of the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured
    along its length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two
    roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown


    surface of the tooth.
    The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
                                                                                                                            M
    longer and more divergent than those of the mandibular second or third molar.
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is
    straighter or slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression
    between the roots that becomes progressively more shallow as it extends occlusally from the
    bifurcation to the cervical line. Occasionally, there is a slight concave area extending across the
    cervical line onto the crown surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are
    usually longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially
    for its cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is
    convex. The distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                       D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                           M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves
    distally in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both roots
    have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Facial
   Outline of the facial surface is trapezoidal with the longer parallel side at occlusal.
   All cusps are visible since the lingual cusps are taller than facial cusps
   As previously noted, the lingual cusps are more pointed while facial cusps (even before wear) are more
    rounded.
   The mesiofacial cusp is the widest of the three facial cusps. Its cuspal ridges meet at an angle that is almost
    flat. The distofacial cusp is almost as wide as the mesiofacial cusp but its cuspal ridges meet more at an
    angle, yet the cusp tip is still considered rounded. The distal cusp makes up a very small part of the total
    mesiodistal width of the facial surface because most of the cusp is lingual to the distofacial line angle
    placing it on the distal aspect of the tooth. The distal cusp is also very rounded occlusally but more pointed
    than either the mesiofacial or distofacial cusp.
   There are two facial grooves seen from the facial view. The mesiofacial groove separates the mesiofacial
    and the distofacial cusps. The distofacial groove separates the distofacial and distal cusps.
   The mesiofacial groove is the shorter of the two. It extends from the occlusal margin of the facial surface
    and terminates about half way to the cervical line. It often ends in a slight depression that extends laterally
    from the terminus of the groove. Also, there is often a pit present at the terminus that frequently requires
    restoration. Clinically these are termed “facial” or “buccal” pits that are considered simple yet necessary


    restorations.
    The facial cervical ridge occupies the area cervical to the lateral depression described above for
                                                                                                                        D
    approximately the mesial 2/3 of the mesiodistal width of the tooth.
   The distofacial groove is somewhat longer and extends onto the more flattened area on the cervical 1/3 of
    the surface distal to the cervical ridge. This groove rarely ends in a pit but it may be fissured along its
    length.
   The cervical line usually dips apically in its center pointing slightly toward the bifurcation of the two roots.
   The mesial outline of the crown is somewhat concave in its cervical 1/3. The distal outline is straighter or
    slightly convex.
   The root trunk on the facial aspect measures 3.0 mm on the average. There is a deep depression between
    the roots that becomes progressively more shallow as it extends occlusally from the bifurcation to the
    cervical line. Occasionally, there is a slight concave area extending across the cervical line onto the crown
    surface of the tooth.
   The two roots are positioned mesially and distally. The roots of the mandibular first molar are usually
    longer and more divergent than those of the mandibular second or third molar.
                                                                                                                            M
   The mesial root is usually a little longer than the distal root. The mesial root usually curves mesially for its
    cervical half then curves distally to a tapered apex. The mesial outline of the mesial root is convex. The
    distal outline of the root is concave.
   The distal root is usually a little shorter, less curved and more pointed at its apex. It usually curves distally
    in its apical 1/3 but it may be straight or even curve slightly to the mesial.
   Both roots are wider mesiodistally in their facial measurement than their lingual measurement. Both
    roots have root depressions on their mesial and distal aspects that are not seen from this view.
    Permanent Mandibular First Molar - Lingual
   From a lingual view the two taller more pointed lingual cusps will
    be seen. Since this tooth converges toward the lingual, a part of the
    outline of the distal cusp will be visible as well.
   The mesiolingual cusp will usually be somewhat taller and a little wider
    than the distolingual cusp.
   The lingual developmental groove extends a short distance onto this
    surface separating the two cusps but rarely if ever is deep enough to
    require restoration (i.e., not fissured).
   The lingual surface of each cusp (lobe) is generally spheroidal in the
    occlusal half. The cervical half of the entire lingual surface is relatively
    smooth and flat.
   It should be noted that the anatomical crown length is the same when               D
    measured facially or lingually although the lingual cusps are taller. The
    cervical line is positioned occlusally approx. 1.0 mm more so on the           M
    lingual surface than on the facial surface. Therefore, the root trunk
    measurement will also be 1 mm longer (average 4.0 mm) from cervical
    line to bifurcation on the lingual aspect of the tooth. It can also be said
    that when measured on the lingual, the total root length is greater
    because the roots are measured from the cervical line to the apex.
   The surface of the root trunk is comparatively flatter than on the facial
    aspect. The developmental depression is deep at the bifurcation;
    however it quickly becomes progressively more shallow and fades out
    entirely before it reaches the cervical line.
    Permanent Mandibular First Molar - Lingual
   From a lingual view the two taller more pointed lingual cusps will be
    seen. Since this tooth converges toward the lingual, a part of the
    outline of the distal cusp will be visible as well.
   The mesiolingual cusp will usually be somewhat taller and a little
    wider than the distolingual cusp.
   The lingual developmental groove extends a short distance onto this
    surface separating the two cusps but rarely if ever is deep enough to
    require restoration (i.e., not fissured).
   The lingual surface of each cusp (lobe) is generally spheroidal in the
    occlusal half. The cervical half of the entire lingual surface is relatively
    smooth and flat.
   It should be noted that the anatomical crown length is the same when               D
    measured facially or lingually although the lingual cusps are taller. The
    cervical line is positioned occlusally approx. 1.0 mm more so on the           M
    lingual surface than on the facial surface. Therefore, the root trunk
    measurement will also be 1 mm longer (average 4.0 mm) from cervical
    line to bifurcation on the lingual aspect of the tooth. It can also be said
    that when measured on the lingual, the total root length is greater
    because the roots are measured from the cervical line to the apex.
   The surface of the root trunk is comparatively flatter than on the facial
    aspect. The developmental depression is deep at the bifurcation;
    however it quickly becomes progressively more shallow and fades out
    entirely before it reaches the cervical line.
    Permanent Mandibular First Molar - Lingual
   From a lingual view the two taller more pointed lingual cusps will be
    seen. Since this tooth converges toward the lingual, a part of the
    outline of the distal cusp will be visible as well.
   The mesiolingual cusp will usually be somewhat taller and a little wider
    than the distolingual cusp.
   The lingual developmental groove extends a short distance onto
    this surface separating the two cusps but rarely if ever is deep
    enough to require restoration (i.e., not fissured).
   The lingual surface of each cusp (lobe) is generally spheroidal in the
    occlusal half. The cervical half of the entire lingual surface is relatively
    smooth and flat.
   It should be noted that the anatomical crown length is the same when               D
    measured facially or lingually although the lingual cusps are taller. The
    cervical line is positioned occlusally approx. 1.0 mm more so on the           M
    lingual surface than on the facial surface. Therefore, the root trunk
    measurement will also be 1 mm longer (average 4.0 mm) from cervical
    line to bifurcation on the lingual aspect of the tooth. It can also be said
    that when measured on the lingual, the total root length is greater
    because the roots are measured from the cervical line to the apex.
   The surface of the root trunk is comparatively flatter than on the facial
    aspect. The developmental depression is deep at the bifurcation;
    however it quickly becomes progressively more shallow and fades out
    entirely before it reaches the cervical line.
    Permanent Mandibular First Molar - Lingual
   From a lingual view the two taller more pointed lingual cusps will be
    seen. Since this tooth converges toward the lingual, a part of the
    outline of the distal cusp will be visible as well.
   The mesiolingual cusp will usually be somewhat taller and a little wider
    than the distolingual cusp.
   The lingual developmental groove extends a short distance onto this
    surface separating the two cusps but rarely if ever is deep enough to
    require restoration (i.e., not fissured).
   The lingual surface of each cusp (lobe) is generally spheroidal in
    the occlusal half. The cervical half of the entire lingual surface is
    relatively smooth and flat.
   It should be noted that the anatomical crown length is the same when              D
    measured facially or lingually although the lingual cusps are taller. The
    cervical line is positioned occlusally approx. 1.0 mm more so on the          M
    lingual surface than on the facial surface. Therefore, the root trunk
    measurement will also be 1 mm longer (average 4.0 mm) from cervical
    line to bifurcation on the lingual aspect of the tooth. It can also be said
    that when measured on the lingual, the total root length is greater
    because the roots are measured from the cervical line to the apex.
   The surface of the root trunk is comparatively flatter than on the facial
    aspect. The developmental depression is deep at the bifurcation;
    however it quickly becomes progressively more shallow and fades out
    entirely before it reaches the cervical line.
    Permanent Mandibular First Molar - Lingual
   From a lingual view the two taller more pointed lingual cusps will be
    seen. Since this tooth converges toward the lingual, a part of the
    outline of the distal cusp will be visible as well.
   The mesiolingual cusp will usually be somewhat taller and a little wider
    than the distolingual cusp.
   The lingual developmental groove extends a short distance onto this
    surface separating the two cusps but rarely if ever is deep enough to
    require restoration (i.e., not fissured).
   The lingual surface of each cusp (lobe) is generally spheroidal in the
    occlusal half. The cervical half of the entire lingual surface is relatively
    smooth and flat.
   It should be noted that the anatomical crown length is the same                    D
    when measured facially or lingually although the lingual cusps are
    taller. The cervical line is positioned occlusally approx. 1.0 mm              M
    more so on the lingual surface than on the facial surface.
    Therefore, the root trunk measurement will also be 1 mm longer
    (average 4.0 mm) from cervical line to bifurcation on the lingual
    aspect of the tooth. It can also be said that when measured on the
    lingual, the total root length is greater because the roots are
    measured from the cervical line to the apex.
   The surface of the root trunk is comparatively flatter than on the facial
    aspect. The developmental depression is deep at the bifurcation;
    however it quickly becomes progressively more shallow and fades out
    entirely before it reaches the cervical line.
    Permanent Mandibular First Molar - Lingual
   From a lingual view the two taller more pointed lingual cusps will be
    seen. Since this tooth converges toward the lingual, a part of the
    outline of the distal cusp will be visible as well.
   The mesiolingual cusp will usually be somewhat taller and a little wider
    than the distolingual cusp.
   The lingual developmental groove extends a short distance onto this
    surface separating the two cusps but rarely if ever is deep enough to
    require restoration (i.e., not fissured).
   The lingual surface of each cusp (lobe) is generally spheroidal in the
    occlusal half. The cervical half of the entire lingual surface is relatively
    smooth and flat.
   It should be noted that the anatomical crown length is the same when               D
    measured facially or lingually although the lingual cusps are taller. The
    cervical line is positioned occlusally approx. 1.0 mm more so on the           M
    lingual surface than on the facial surface. Therefore, the root trunk
    measurement will also be 1 mm longer (average 4.0 mm) from cervical
    line to bifurcation on the lingual aspect of the tooth. It can also be said
    that when measured on the lingual, the total root length is greater
    because the roots are measured from the cervical line to the apex.
   The surface of the root trunk is comparatively flatter than on the
    facial aspect. The developmental depression is deep at the
    bifurcation; however it quickly becomes progressively more
    shallow and fades out entirely before it reaches the cervical line.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer
    root measurement along its lingual outline from the cervical line to               L
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This      F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third
    of the crown and is termed the cervical ridge. The crest is
    somewhat higher occlusally when compared to the cervical ridges
    found on maxillary molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer
    root measurement along its lingual outline from the cervical line to              L
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This     F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally)
    in the middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer
    root measurement along its lingual outline from the cervical line to               L
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This      F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only
    the mesiofacial and mesiolingual cusps will be visible from this
    view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer             L
    root measurement along its lingual outline from the cervical line to
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This
                                                                                   F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially
    and lingually is because of a slant in the level of the cervical line (it
    is higher occlusally at its lingual end). This also accounts for a
    longer root measurement along its lingual outline from the cervical                L
    line to apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This      F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer
    root measurement along its lingual outline from the cervical line to               L
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of
    its mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This      F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer
    root measurement along its lingual outline from the cervical line to               L
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than
    the distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This      F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer
    root measurement along its lingual outline from the cervical line to               L
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown.           F
    This also contributes to a shorter, straighter facial root outline
    compared to a longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root depression
    extending the full length of the root. A similar depression will be found
    on the distal side of this same root as well. From both mesial and distal
    aspects, this root is convex at its facial and lingual borders with this
    broad concavity in between.
    Permanent Mandibular First Molar - Mesial
   The crown outline from the mesial view is rhomboidal.
   The greatest curvature of the facial outline is at the cervical third of the
    crown and is termed the cervical ridge. The crest is somewhat higher
    occlusally when compared to the cervical ridges found on maxillary
    molars but it is still in the cervical one-third.
   The greatest curvature of the lingual outline is higher (occlusally) in the
    middle third of the crown.
   Since mesial cusps are taller than the distal cusps of the tooth, only the
    mesiofacial and mesiolingual cusps will be visible from this view.
   The fact that anatomical crown length measures the same facially and
    lingually is because of a slant in the level of the cervical line (it is
    higher occlusally at its lingual end). This also accounts for a longer
    root measurement along its lingual outline from the cervical line to               L
    apex.
   The cervical line curves occlusally about 1.0 mm near the center of its
    mesial segment.
   Only the mesial root is visible since it is wider faciolingually than the
    distal root and is usually a little longer.
   The mesial root apex is located directly below the mesiofacial cusp
    slightly facial to the faciolingual long axis bisector of the crown. This      F
    also contributes to a shorter, straighter facial root outline compared to a
    longer more slanted lingual outline.
   The mesial root presents a rather wide developmental root
    depression extending the full length of the root. A similar
    depression will be found on the distal side of this same root as well.
    From both mesial and distal aspects, this root is convex at its facial
    and lingual borders with this broad concavity in between.
    Permanent Mandibular First Molar - Distal
   From the distal view the crown outline is also
    rhomboidal.
   It has already been noted that the distal cusp is located far
    enough around the distofacial line angle of the tooth to be
    considered partly on the distal surface. It is also obvious
    from the occlusal view that the facial surface converges to the
    lingual as it nears the distofacial line angle.
   Therefore, from a distal view, the outline of the distal cusp
    will be seen superimposed on the distofacial cusp. Also, part
    of the facial surface of the crown will be visible.
   The cervical line across the distal surface is relatively straight
                                                                             F
    with little or no curve occlusally.
   Both the mesial and distal roots will be visible from this
    view.
   The distal root is narrower and shorter and the apex is more
    pointed than the mesial root; therefore, the outline of the          L
    mesial root will be evident beyond the outline of the distal
    root along at least one border.
   There may be longitudinal root depressions on the mesial and
    distal aspects of the distal root. However, they are narrower
    faciolingually and not as deep as those found on the mesial
    root.
    Permanent Mandibular First Molar - Distal
   From the distal view the crown outline is also rhomboidal.
   It has already been noted that the distal cusp is located
    far enough around the distofacial line angle of the tooth
    to be considered partly on the distal surface. It is also
    obvious from the occlusal view that the facial surface
    converges to the lingual as it nears the distofacial line
    angle.
   Therefore, from a distal view, the outline of the distal cusp
    will be seen superimposed on the distofacial cusp. Also, part
    of the facial surface of the crown will be visible.
   The cervical line across the distal surface is relatively straight
                                                                             F
    with little or no curve occlusally.
   Both the mesial and distal roots will be visible from this
    view.
   The distal root is narrower and shorter and the apex is more
    pointed than the mesial root; therefore, the outline of the          L
    mesial root will be evident beyond the outline of the distal
    root along at least one border.
   There may be longitudinal root depressions on the mesial and
    distal aspects of the distal root. However, they are narrower
    faciolingually and not as deep as those found on the mesial
    root.
    Permanent Mandibular First Molar - Distal
   From the distal view the crown outline is also rhomboidal.
   It has already been noted that the distal cusp is located far
    enough around the distofacial line angle of the tooth to be
    considered partly on the distal surface. It is also obvious
    from the occlusal view that the facial surface converges to the
    lingual as it nears the distofacial line angle.
   Therefore, from a distal view, the outline of the distal
    cusp will be seen superimposed on the distofacial cusp.
    Also, part of the facial surface of the crown will be visible.
   The cervical line across the distal surface is relatively straight
    with little or no curve occlusally.
                                                                             F
   Both the mesial and distal roots will be visible from this
    view.
   The distal root is narrower and shorter and the apex is more
    pointed than the mesial root; therefore, the outline of the
    mesial root will be evident beyond the outline of the distal         L
    root along at least one border.
   There may be longitudinal root depressions on the mesial and
    distal aspects of the distal root. However, they are narrower
    faciolingually and not as deep as those found on the mesial
    root.
    Permanent Mandibular First Molar - Distal
   From the distal view the crown outline is also rhomboidal.
   It has already been noted that the distal cusp is located far
    enough around the distofacial line angle of the tooth to be
    considered partly on the distal surface. It is also obvious
    from the occlusal view that the facial surface converges to the
    lingual as it nears the distofacial line angle.
   Therefore, from a distal view, the outline of the distal cusp
    will be seen superimposed on the distofacial cusp. Also, part
    of the facial surface of the crown will be visible.
   The cervical line across the distal surface is relatively
    straight with little or no curve occlusally.
                                                                          F
   Both the mesial and distal roots will be visible from this
    view.
   The distal root is narrower and shorter and the apex is more
    pointed than the mesial root; therefore, the outline of the
    mesial root will be evident beyond the outline of the distal      L
    root along at least one border.
   There may be longitudinal root depressions on the mesial and
    distal aspects of the distal root. However, they are narrower
    faciolingually and not as deep as those found on the mesial
    root.
    Permanent Mandibular First Molar - Distal
   From the distal view the crown outline is also rhomboidal.
   It has already been noted that the distal cusp is located far
    enough around the distofacial line angle of the tooth to be
    considered partly on the distal surface. It is also obvious
    from the occlusal view that the facial surface converges to the
    lingual as it nears the distofacial line angle.
   Therefore, from a distal view, the outline of the distal cusp
    will be seen superimposed on the distofacial cusp. Also, part
    of the facial surface of the crown will be visible.
   The cervical line across the distal surface is relatively straight
    with little or no curve occlusally.
                                                                             F
   Both the mesial and distal roots will be visible from this
    view.
   The distal root is narrower and shorter and the apex is more
    pointed than the mesial root; therefore, the outline of the
    mesial root will be evident beyond the outline of the distal         L
    root along at least one border.
   There may be longitudinal root depressions on the mesial and
    distal aspects of the distal root. However, they are narrower
    faciolingually and not as deep as those found on the mesial
    root.
    Permanent Mandibular First Molar - Distal
   From the distal view the crown outline is also rhomboidal.
   It has already been noted that the distal cusp is located far
    enough around the distofacial line angle of the tooth to be
    considered partly on the distal surface. It is also obvious
    from the occlusal view that the facial surface converges to the
    lingual as it nears the distofacial line angle.
   Therefore, from a distal view, the outline of the distal cusp
    will be seen superimposed on the distofacial cusp. Also, part
    of the facial surface of the crown will be visible.
   The cervical line across the distal surface is relatively straight
    with little or no curve occlusally.
                                                                             F
   Both the mesial and distal roots will be visible from this
    view.
   The distal root is narrower and shorter and the apex is
    more pointed than the mesial root; therefore, the outline
    of the mesial root will be evident beyond the outline of the         L
    distal root along at least one border.
   There may be longitudinal root depressions on the mesial and
    distal aspects of the distal root. However, they are narrower
    faciolingually and not as deep as those found on the mesial
    root.
    Permanent Mandibular First Molar - Distal
   From the distal view the crown outline is also rhomboidal.
   It has already been noted that the distal cusp is located far
    enough around the distofacial line angle of the tooth to be
    considered partly on the distal surface. It is also obvious
    from the occlusal view that the facial surface converges to the
    lingual as it nears the distofacial line angle.
   Therefore, from a distal view, the outline of the distal cusp
    will be seen superimposed on the distofacial cusp. Also, part
    of the facial surface of the crown will be visible.
   The cervical line across the distal surface is relatively straight
    with little or no curve occlusally.
                                                                             F
   Both the mesial and distal roots will be visible from this
    view.
   The distal root is narrower and shorter and the apex is more
    pointed than the mesial root; therefore, the outline of the
    mesial root will be evident beyond the outline of the distal         L
    root along at least one border.
   There may be longitudinal root depressions on the mesial
    and distal aspects of the distal root. However, they are
    narrower faciolingually and not as deep as those found on
    the mesial root.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical
    ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
                                                                                                     M   D
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than
    lingual half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0
    mm cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the
    corner of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial,
    distofacial, mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3)
    (similar in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or
    fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
                                                                                                   M   D
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather
    pointed cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather
    rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
                                                                                                     M   D
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial
    triangular fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular
    fossa through the central fossa to the distal pit in the distal triangular fossa. The
    mesiofacial groove extends facially (or slightly in a mesiofacial direction) at the
    deepest part of the sulcus between the mesiofacial and distofacial cusps. The
                                                                                                     M   D
    distofacial groove extends from the central groove in a distofacial direction at the
    deepest part of the sulcus between the distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface
    of the crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W”
    or “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the
    central groove (depending on the perspective of the viewer). The “Y” comparison
    considers the paths of the mesiofacial, distofacial and lingual grooves and that
    segment of the central groove between them. It ignores the mesial and distal
    extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them meet.
    This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Occlusal
   Occlusal crown outline said to be hexagonal (Wheeler) or pentagonal (Kraus)
   Faciolingual measurement is greatest in mesial half of crown (because of cervical ridge).
   Tooth converges toward lingual. The facial half of the crown is much wider than lingual
    half.
   Mesial contact area is located slightly facial to the faciolingual bisector and about 1.0 mm
    cervical to mesial marginal ridge.
   Distal contact area is also located facial to the faciolingual bisector and about 1.0 mm
    cervical to the distal cuspal ridge of the distal cusp.
   Crown has five cusps. Three cusps are located on the facial half of the crown and two
    cusps are located on the lingual half.
   The most distally located cusp on the facial half is located far enough around on the corner
    of the crown to be called the distal cusp.
   The other cusps are named according to their general location as mesiofacial, distofacial,
    mesiolingual and distolingual.
   In order of greatest size development, the cusps are listed: 1) mesiofacial; 2 and 3) (similar
    in development) mesiolingual and distolingual; 4) distofacial and 5) distal (or fifth) cusp.
   In order of cusp height: 1) mesiolingual; 2) distolingual (both presenting rather pointed
    cusps); 3) mesiofacial, 4) distofacial, and 5) distal all presenting rather rounded cusps.
   There is one major fossa - the central fossa and two minor fossae - the mesial triangular
    fossa and the distal triangular fossa.
   There are four major developmental grooves. The central groove runs irregularly
    mesiodistally across the occlusal surface from the mesial pit in the mesial triangular fossa
    through the central fossa to the distal pit in the distal triangular fossa. The mesiofacial
    groove extends facially (or slightly in a mesiofacial direction) at the deepest part of the
    sulcus between the mesiofacial and distofacial cusps. The distofacial groove extends from
                                                                                                     M   D
    the central groove in a distofacial direction at the deepest part of the sulcus between the
    distofacial and distal cusps.
   The mesiofacial groove and the distofacial groove extend over onto the facial surface of the
    crown.
   The groove pattern of this tooth is described by various authors as shaped like a “W” or
    “M” or “Y”. The “M” or “W” configuration best describes the wanderings of the central
    groove (depending on the perspective of the viewer). The “Y” comparison considers the
    paths of the mesiofacial, distofacial and lingual grooves and that segment of the central
    groove between them. It ignores the mesial and distal extensions of the central groove.
   Note that each cusp has a definite triangular ridge, but also note that none of them
    meet. This produces an occlusal surface that has no transverse ridges.
    Permanent Mandibular First Molar - Summary
   Two roots (mesial & distal) that are wider in a faciolingual
    direction
   Five cusps (three facial and two lingual)
   MF groove separates the MF & DF cusps; DF groove separates
    the DF and distal cusps
   MF grooves terminates at the facial (buccal) pit
   Mesial surface of the crown is concave in the cervical third and
    highly convex at the upper two-thirds; the distal surface is
    convex throughout
   Facial surface wider mesiodistally than the lingual surface
    (lingual convergence)
   Lingual groove separates two lingual cusps
   Both mesial marginal ridge (longer) and distal marginal ridge
    (shorter) are interrupted by developmental grooves
   Crown outline is pentagonal (Wheeler describes it as hexagonal)
   Three occlusal fossae: Central with central pit; extending from
    this pit are the mesiofacial and lingual grooves and through it
    runs the central groove. The MTF and the DTF contain their
    respective mesial and distal pits which are termini for the central
    groove. The distofacial groove originates from the central
    groove, distal to the central pit.
   Mesial and distal roots are joined at a common root trunk; both
    roots curve slightly to the distal and are blunt. The mesial root is
    the broadest (FL) of any root in the arch.
   The mesial root is slightly larger than the distal root and has a
    distinct developmental root depression on its mesial and distal
    surfaces. This root has two pulp canals, one facial and one
    lingual.
Mandibular Second Molar
Calcification and Eruption
   Calcification begins…………3 years

   Crown completed……………7-8 years

   Eruption……………………..11-13 years

   Root completed……………..14 -15 years
    Permanent Mandibular Second Molar – Facial
   The crown is narrower mesiodistally and shorter
    occlusocervically than that of a mandibular first molar.
   All four cusps will be visible since the lingual cusps are taller
    than facial cusps. Mesial cusps will be a little taller than
    distal cusps.
   Lingual cusps are sharper and more pointed than facial cusps
    which are flatter and more rounded.
   There is only one facial groove. It is simply called the facial
    (or “buccal”) groove. It separates the mesiofacial and
    distofacial cusps and extends only a short distance onto the
    facial surface. There is rarely a facial (buccal) pit at the
    termination of this groove.                                              M
   The two facial cusps are about equal in mesiodistal width.
                                                                         D
   The cervical ridge is more prominent on the mesial half of the
    crown surface.
   The two roots are termed the mesial and distal roots. They
    vary greatly in length and divergence, but generally it may be
    said that (1) the mesial root will be longer than the distal root,
    (2) the roots are usually closer together than those of the first
    molar, (3) the roots may be fused together for all or part of
    their length; (4) the roots incline distally more than those of
    the first molar, and (5) the root trunk will be shorter than that
    of the first molar.
    Permanent Mandibular Second Molar – Facial
   The crown is narrower mesiodistally and shorter
    occlusocervically than that of a mandibular first molar.
   All four cusps will be visible since the lingual cusps are
    taller than facial cusps. Mesial cusps will be a little taller
    than distal cusps.
   Lingual cusps are sharper and more pointed than facial cusps
    which are flatter and more rounded.
   There is only one facial groove. It is simply called the facial
    (or “buccal”) groove. It separates the mesiofacial and
    distofacial cusps and extends only a short distance onto the
    facial surface. There is rarely a facial (buccal) pit at the
    termination of this groove.                                              M
   The two facial cusps are about equal in mesiodistal width.
                                                                         D
   The cervical ridge is more prominent on the mesial half of the
    crown surface.
   The two roots are termed the mesial and distal roots. They
    vary greatly in length and divergence, but generally it may be
    said that (1) the mesial root will be longer than the distal root,
    (2) the roots are usually closer together than those of the first
    molar, (3) the roots may be fused together for all or part of
    their length; (4) the roots incline distally more than those of
    the first molar, and (5) the root trunk will be shorter than that
    of the first molar.
    Permanent Mandibular Second Molar – Facial
   The crown is narrower mesiodistally and shorter
    occlusocervically than that of a mandibular first molar.
   All four cusps will be visible since the lingual cusps are taller
    than facial cusps. Mesial cusps will be a little taller than
    distal cusps.
   Lingual cusps are sharper and more pointed than facial
    cusps which are flatter and more rounded.
   There is only one facial groove. It is simply called the facial
    (or “buccal”) groove. It separates the mesiofacial and
    distofacial cusps and extends only a short distance onto the
    facial surface. There is rarely a facial (buccal) pit at the
    termination of this groove.                                              M
   The two facial cusps are about equal in mesiodistal width.
                                                                         D
   The cervical ridge is more prominent on the mesial half of the
    crown surface.
   The two roots are termed the mesial and distal roots. They
    vary greatly in length and divergence, but generally it may be
    said that (1) the mesial root will be longer than the distal root,
    (2) the roots are usually closer together than those of the first
    molar, (3) the roots may be fused together for all or part of
    their length; (4) the roots incline distally more than those of
    the first molar, and (5) the root trunk will be shorter than that
    of the first molar.
    Permanent Mandibular Second Molar – Facial
   The crown is narrower mesiodistally and shorter
    occlusocervically than that of a mandibular first molar.
   All four cusps will be visible since the lingual cusps are taller
    than facial cusps. Mesial cusps will be a little taller than
    distal cusps.
   Lingual cusps are sharper and more pointed than facial cusps
    which are flatter and more rounded.
   There is only one facial groove. It is simply called the
    facial (or “buccal”) groove. It separates the mesiofacial
    and distofacial cusps and extends only a short distance
    onto the facial surface. There is rarely a facial (buccal) pit
    at the termination of this groove.                                       M
   The two facial cusps are about equal in mesiodistal width.
                                                                         D
   The cervical ridge is more prominent on the mesial half of the
    crown surface.
   The two roots are termed the mesial and distal roots. They
    vary greatly in length and divergence, but generally it may be
    said that (1) the mesial root will be longer than the distal root,
    (2) the roots are usually closer together than those of the first
    molar, (3) the roots may be fused together for all or part of
    their length; (4) the roots incline distally more than those of
    the first molar, and (5) the root trunk will be shorter than that
    of the first molar.
    Permanent Mandibular Second Molar – Facial
   The crown is narrower mesiodistally and shorter
    occlusocervically than that of a mandibular first molar.
   All four cusps will be visible since the lingual cusps are taller
    than facial cusps. Mesial cusps will be a little taller than
    distal cusps.
   Lingual cusps are sharper and more pointed than facial cusps
    which are flatter and more rounded.
   There is only one facial groove. It is simply called the facial
    (or “buccal”) groove. It separates the mesiofacial and
    distofacial cusps and extends only a short distance onto the
    facial surface. There is rarely a facial (buccal) pit at the
    termination of this groove.                                              M
   The two facial cusps are about equal in mesiodistal width.
                                                                         D
   The cervical ridge is more prominent on the mesial half of the
    crown surface.
   The two roots are termed the mesial and distal roots. They
    vary greatly in length and divergence, but generally it may be
    said that (1) the mesial root will be longer than the distal root,
    (2) the roots are usually closer together than those of the first
    molar, (3) the roots may be fused together for all or part of
    their length; (4) the roots incline distally more than those of
    the first molar, and (5) the root trunk will be shorter than that
    of the first molar.
    Permanent Mandibular Second Molar – Facial
   The crown is narrower mesiodistally and shorter
    occlusocervically than that of a mandibular first molar.
   All four cusps will be visible since the lingual cusps are taller
    than facial cusps. Mesial cusps will be a little taller than
    distal cusps.
   Lingual cusps are sharper and more pointed than facial cusps
    which are flatter and more rounded.
   There is only one facial groove. It is simply called the facial
    (or “buccal”) groove. It separates the mesiofacial and
    distofacial cusps and extends only a short distance onto the
    facial surface. There is rarely a facial (buccal) pit at the
    termination of this groove.                                              M
   The two facial cusps are about equal in mesiodistal width.
                                                                         D
   The cervical ridge is more prominent on the mesial half of
    the crown surface.
   The two roots are termed the mesial and distal roots. They
    vary greatly in length and divergence, but generally it may be
    said that (1) the mesial root will be longer than the distal root,
    (2) the roots are usually closer together than those of the first
    molar, (3) the roots may be fused together for all or part of
    their length; (4) the roots incline distally more than those of
    the first molar, and (5) the root trunk will be shorter than that
    of the first molar.
    Permanent Mandibular Second Molar – Facial
   The crown is narrower mesiodistally and shorter
    occlusocervically than that of a mandibular first molar.
   All four cusps will be visible since the lingual cusps are taller
    than facial cusps. Mesial cusps will be a little taller than
    distal cusps.
   Lingual cusps are sharper and more pointed than facial cusps
    which are flatter and more rounded.
   There is only one facial groove. It is simply called the facial
    (or “buccal”) groove. It separates the mesiofacial and
    distofacial cusps and extends only a short distance onto the
    facial surface. There is rarely a facial (buccal) pit at the
    termination of this groove.                                             M
   The two facial cusps are about equal in mesiodistal width.
                                                                        D
   The cervical ridge is more prominent on the mesial half of the
    crown surface.
   The two roots are termed the mesial and distal roots.
    They vary greatly in length and divergence, but generally
    it may be said that (1) the mesial root will be longer than
    the distal root, (2) the roots are usually closer together
    than those of the first molar, (3) the roots may be fused
    together for all or part of their length; (4) the roots incline
    distally more than those of the first molar, and (5) the root
    trunk will be shorter than that of the first molar.
    Permanent Mandibular Second Molar – Lingual
   The lingual convergence of the mandibular
    second molar is considerably less than that of
    the first molar; the lingual width measurement
    of the mandibular second molar may actually
    be wider than the lingual width measurement
    of the mandibular first molar of the same
    dentition.
   Very little of the mesial or distal surfaces will be
    seen from a lingual view.
   As was noted on the mandibular first molar, the        M   D
    crown length when measured from cusp tip to
    cervical line is about the same on both the facial
    and lingual surfaces. With the lingual cusps being
    taller, this is because the cervical line is higher
    (occlusally) on the lingual surface thereby
    producing equal measurements. This also makes
    the measurement of the length of both the root
    trunk and the total root length greater on the
    lingual aspect as measured from the cervical line.
    Permanent Mandibular Second Molar – Lingual
   The lingual convergence of the mandibular
    second molar is considerably less than that of the
    first molar; the lingual width measurement of the
    mandibular second molar may actually be wider
    than the lingual width measurement of the
    mandibular first molar of the same dentition.
   Very little of the mesial or distal surfaces will
    be seen from a lingual view.
   As was noted on the mandibular first molar, the
    crown length when measured from cusp tip to           M   D
    cervical line is about the same on both the facial
    and lingual surfaces. With the lingual cusps being
    taller, this is because the cervical line is higher
    (occlusally) on the lingual surface thereby
    producing equal measurements. This also makes
    the measurement of the length of both the root
    trunk and the total root length greater on the
    lingual aspect as measured from the cervical line.
    Permanent Mandibular Second Molar – Lingual
   The lingual convergence of the mandibular
    second molar is considerably less than that of the
    first molar; the lingual width measurement of the
    mandibular second molar may actually be wider
    than the lingual width measurement of the
    mandibular first molar of the same dentition.
   Very little of the mesial or distal surfaces will be
    seen from a lingual view.
   As was noted on the mandibular first molar,
    the crown length when measured from cusp tip           M   D
    to cervical line is about the same on both the
    facial and lingual surfaces. With the lingual
    cusps being taller, this is because the cervical
    line is higher (occlusally) on the lingual surface
    thereby producing equal measurements. This
    also makes the measurement of the length of
    both the root trunk and the total root length
    greater on the lingual aspect as measured from
    the cervical line.
    Permanent Mandibular Second Molar – Mesial
   The greatest facial curvature is in the
    cervical one-third and is termed the
    cervical ridge.
   The greatest lingual curvature is in the
    middle one-third.
   The tips of the facial cusps are nearer the
    faciolingual long axis bisector than are
    the tips of the lingual cusps.
   The facial cusps are shorter and more             L
    rounded.
   The lingual cusps are longer and more
    pointed.
   The mesial root is very similar in shape
    to the mesial root of the mandibular first    F
    molar. The root depression and surface
    contour is also the same.
    Permanent Mandibular Second Molar – Mesial
   The greatest facial curvature is in the
    cervical one-third and is termed the
    cervical ridge.
   The greatest lingual curvature is in the
    middle one-third.
   The tips of the facial cusps are nearer the
    faciolingual long axis bisector than are
    the tips of the lingual cusps.
   The facial cusps are shorter and more             L
    rounded.
   The lingual cusps are longer and more
    pointed.
   The mesial root is very similar in shape
    to the mesial root of the mandibular first    F
    molar. The root depression and surface
    contour is also the same.
    Permanent Mandibular Second Molar – Mesial
   The greatest facial curvature is in the
    cervical one-third and is termed the
    cervical ridge.
   The greatest lingual curvature is in the
    middle one-third.
   The tips of the facial cusps are nearer
    the faciolingual long axis bisector than
    are the tips of the lingual cusps.
   The facial cusps are shorter and more            L
    rounded.
   The lingual cusps are longer and more
    pointed.
   The mesial root is very similar in shape
    to the mesial root of the mandibular first   F
    molar. The root depression and surface
    contour is also the same.
    Permanent Mandibular Second Molar – Mesial
   The greatest facial curvature is in the
    cervical one-third and is termed the
    cervical ridge.
   The greatest lingual curvature is in the
    middle one-third.
   The tips of the facial cusps are nearer the
    faciolingual long axis bisector than are
    the tips of the lingual cusps.
   The facial cusps are shorter and more             L
    rounded.
   The lingual cusps are longer and more
    pointed.
   The mesial root is very similar in shape
    to the mesial root of the mandibular first    F
    molar. The root depression and surface
    contour is also the same.
    Permanent Mandibular Second Molar – Mesial
   The greatest facial curvature is in the
    cervical one-third and is termed the
    cervical ridge.
   The greatest lingual curvature is in the
    middle one-third.
   The tips of the facial cusps are nearer the
    faciolingual long axis bisector than are
    the tips of the lingual cusps.
   The facial cusps are shorter and more             L
    rounded.
   The lingual cusps are longer and more
    pointed.
   The mesial root is very similar in shape
    to the mesial root of the mandibular first    F
    molar. The root depression and surface
    contour is also the same.
    Permanent Mandibular Second Molar – Mesial
   The greatest facial curvature is in the
    cervical one-third and is termed the
    cervical ridge.
   The greatest lingual curvature is in the
    middle one-third.
   The tips of the facial cusps are nearer the
    faciolingual long axis bisector than are
    the tips of the lingual cusps.
   The facial cusps are shorter and more             L
    rounded.
   The lingual cusps are longer and more
    pointed.
   The mesial root is very similar in shape
    to the mesial root of the mandibular          F
    first molar. The root depression and
    surface contour is also the same.
    Permanent Mandibular Second Molar – Distal
   The distal view of a mandibular second
    molar differs primarily from that view
    of a mandibular first molar in that the
    second molar has no distal cusp.
   Otherwise, the contours of the crown and
    roots will be very similar. The lack of
    curvature in and the slanted position of
    the cervical line can be described the
    same as it was for the mandibular first
    molar.
   The distal surface of the crown of the
    mandibular second molar is likely to be         F
    more rounded (convex) than that of the      L
    mandibular first molar. This often places
    the distal contact area (with the third
    molar) almost centered, both
    faciolingually and occlusocervically.
    Permanent Mandibular Second Molar – Distal
   The distal view of a mandibular second
    molar differs primarily from that view of
    a mandibular first molar in that the
    second molar has no distal cusp.
   Otherwise, the contours of the crown
    and roots will be very similar. The
    lack of curvature in and the slanted
    position of the cervical line can be
    described the same as it was for the
    mandibular first molar.
   The distal surface of the crown of the
    mandibular second molar is likely to be         F
    more rounded (convex) than that of the      L
    mandibular first molar. This often places
    the distal contact area (with the third
    molar) almost centered, both
    faciolingually and occlusocervically.
    Permanent Mandibular Second Molar – Distal
   The distal view of a mandibular second
    molar differs primarily from that view of
    a mandibular first molar in that the
    second molar has no distal cusp.
   Otherwise, the contours of the crown and
    roots will be very similar. The lack of
    curvature in and the slanted position of
    the cervical line can be described the
    same as it was for the mandibular first
    molar.
   The distal surface of the crown of the
    mandibular second molar is likely to            F
    be more rounded (convex) than that of       L
    the mandibular first molar. This often
    places the distal contact area (with the
    third molar) almost centered, both
    faciolingually and occlusocervically.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.
   The central pit forms where the facial, lingual and central grooves meet and this is       D
    within the central fossa. The terminal ends of the central groove are in the mesial
    triangular fossa and the distal triangular fossa and each end has its respective       M
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown.
    This is because the cervical ridge is usually more prominent on the
    mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.                                                            D
   The central pit forms where the facial, lingual and central grooves meet and this is
    within the central fossa. The terminal ends of the central groove are in the mesial    M
    triangular fossa and the distal triangular fossa and each end has its respective
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to
    converge toward the distal. The distal outline is rather rounded (semi-
    circular) compared with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.
   The central pit forms where the facial, lingual and central grooves meet and this is       D
    within the central fossa. The terminal ends of the central groove are in the mesial
    triangular fossa and the distal triangular fossa and each end has its respective       M
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All
    four are of nearly equal size. The tips of the facial cusps (especially the
    mesiofacial cusp) are usually located farther lingually from the facial outline
    than is true of the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.
   The central pit forms where the facial, lingual and central grooves meet and this is       D
    within the central fossa. The terminal ends of the central groove are in the mesial
    triangular fossa and the distal triangular fossa and each end has its respective       M
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual
    to the faciolingual bisector. The facial groove and the lingual groove cross
    the central groove at right angles dividing the occlusal surface into mesial
    and distal halves. These three major grooves present a groove structure
    which is said to be a “+” or “cross” design. One author calls this a 4+
    arrangement because there are 4 cusps of approximately equal size with a
    “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.                                                            D
   The central pit forms where the facial, lingual and central grooves meet and this is
    within the central fossa. The terminal ends of the central groove are in the mesial    M
    triangular fossa and the distal triangular fossa and each end has its respective
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial &
    mesiolingual as well as a distofacial & distolingual groove at the proximal
    ends of the central groove. Also, there are often many supplemental grooves
    associated with the occlusal surface of this tooth.
   The central pit forms where the facial, lingual and central grooves meet and this is       D
    within the central fossa. The terminal ends of the central groove are in the mesial
    triangular fossa and the distal triangular fossa and each end has its respective       M
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.
   The central pit forms where the facial, lingual and central grooves meet and               D
    this is within the central fossa. The terminal ends of the central groove are in
    the mesial triangular fossa and the distal triangular fossa and each end has           M
    its respective mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.
   The central pit forms where the facial, lingual and central grooves meet and this is       D
    within the central fossa. The terminal ends of the central groove are in the mesial
    triangular fossa and the distal triangular fossa and each end has its respective       M
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge
    that extends toward the central fossa. On most specimens the triangular
    ridges meet in such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the distal
    border is the distal marginal ridge. The occlusal table is said to be rectangular.
    Permanent Mandibular Second Molar – Occlusal
   All mandibular molars are wider in their mesiodistal dimension.
   Greatest faciolingual measurement is usually in the mesial half of crown. This is
    because the cervical ridge is usually more prominent on the mesiofacial lobe.
   Although the crown outline is said to be rectangular, the crown tends to converge
    toward the distal. The distal outline is rather rounded (semi-circular) compared
    with a more square mesial outline.
   The crown has four well developed cusps: two facial and two lingual. All four
    are of nearly equal size. The tips of the facial cusps (especially the mesiofacial
    cusp) are usually located farther lingually from the facial outline than is true of
    the tips of the lingual cusps in relation to the lingual outline.
   The central groove crosses the occlusal surface mesiodistally slightly lingual to
    the faciolingual bisector. The facial groove and the lingual groove cross the
    central groove at right angles dividing the occlusal surface into mesial and distal
    halves. These three major grooves present a groove structure which is said to be a
    “+” or “cross” design. One author calls this a 4+ arrangement because there are 4
    cusps of approximately equal size with a “+” sign dividing them.
   There is usually a suggestion (if not a presence) of a mesiofacial & mesiolingual
    as well as a distofacial & distolingual groove at the proximal ends of the central
    groove. Also, there are often many supplemental grooves associated with the
    occlusal surface of this tooth.
   The central pit forms where the facial, lingual and central grooves meet and this is       D
    within the central fossa. The terminal ends of the central groove are in the mesial
    triangular fossa and the distal triangular fossa and each end has its respective       M
    mesial and distal pit.
   Each cusp has its mesial and distal cuspal ridges as well as a triangular ridge that
    extends toward the central fossa. On most specimens the triangular ridges meet in
    such a way as to form two transverse ridges.
   The mesial border of the occlusal table is the mesial marginal ridge and the
    distal border is the distal marginal ridge. The occlusal table is said to be
    rectangular.
Permanent Mandibular Second Molar - Summary
   All four cusps visible (lingual cusps taller than facial cusps)
   Facial groove separates MF & DF cusps
                                                                            Facial
   Cervical ridge is more prominent on mesial half of crown surface

   Taller more pointed lingual cusps
   Lingual convergence not a pronounced as that of mandibular 1st
    molar                                                                   Lingual

   Cervical ridge greatest facial curvature
   Greatest lingual curvature at middle third
   Facial cusps shorter and more rounded
                                                                            Mesial

   Distal root slightly shorter than mesial root
   Distal contact centered occlusocervically and faciolingually             Distal
   Greatest faciolingual measurement at mesial half of crown because of
    cervical ridge
   Four cusps of near equal size separated by “+” developmental
    grooves                                                                Occlusal
   Three fossae: Central, MTF and DTF
Similarities Between the  1st

and 2nd Mandibular Molars
  Widest dimension is
   mesiodistal
  Lingual cusps taller
   and more pointed
  3 occlusal fossae
  2 roots, 3 canals
Differences Between the           1 st

and 2nd Mandibular Molars

*   Second molar
    traits:
    *   Slightly smaller in all
        dimensions
    *   4 cusps/4 lobes
    *   Minimal taper
Mandibular Third Molar
Calcification / Eruption
    Calcification begins…………….9 years

    Crown completed…………12-16 years

    Eruption…………………….17-21 years

    Root completed…………….18-25 years
    Permanent Mandibular Third Molar – Facial
   The crown from the facial aspect will present
    either two facial cusps (similar in relative size
    and placement to those of the mandibular
    second molar) or three cusps (similar in
    relative size and placement to those of the
    mandibular first molar).
   Facial and lingual cusps are likely to be more
    nearly the same height on third molars.
   Facial (buccal) grooves are not likely to be deep
    or fissured.
   The typical third molar will have two roots
    (mesial and distal). These will usually be shorter       M
    and curved more toward the distal with a higher      D
    degree of inclination relative to the occlusal
    plane. The roots may be separated or fused for
    all or part of their length.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Facial
   The crown from the facial aspect will present
    either two facial cusps (similar in relative size
    and placement to those of the mandibular second
    molar) or three cusps (similar in relative size and
    placement to those of the mandibular first
    molar).
   Facial and lingual cusps are likely to be more
    nearly the same height on third molars.
   Facial (buccal) grooves are not likely to be deep
    or fissured.
   The typical third molar will have two roots
    (mesial and distal). These will usually be shorter        M
    and curved more toward the distal with a higher       D
    degree of inclination relative to the occlusal
    plane. The roots may be separated or fused for
    all or part of their length.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Facial
   The crown from the facial aspect will present
    either two facial cusps (similar in relative size
    and placement to those of the mandibular second
    molar) or three cusps (similar in relative size and
    placement to those of the mandibular first
    molar).
   Facial and lingual cusps are likely to be more
    nearly the same height on third molars.
   Facial (buccal) grooves are not likely to be
    deep or fissured.
   The typical third molar will have two roots
    (mesial and distal). These will usually be shorter        M
    and curved more toward the distal with a higher       D
    degree of inclination relative to the occlusal
    plane. The roots may be separated or fused for
    all or part of their length.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Facial
   The crown from the facial aspect will present
    either two facial cusps (similar in relative size
    and placement to those of the mandibular second
    molar) or three cusps (similar in relative size and
    placement to those of the mandibular first
    molar).
   Facial and lingual cusps are likely to be more
    nearly the same height on third molars.
   Facial (buccal) grooves are not likely to be deep
    or fissured.
   The typical third molar will have two roots
    (mesial and distal). These will usually be                M
    shorter and curved more toward the distal             D
    with a higher degree of inclination relative to
    the occlusal plane. The roots may be
    separated or fused for all or part of their
    length.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Facial
   The crown from the facial aspect will present
    either two facial cusps (similar in relative size
    and placement to those of the mandibular second
    molar) or three cusps (similar in relative size and
    placement to those of the mandibular first
    molar).
   Facial and lingual cusps are likely to be more
    nearly the same height on third molars.
   Facial (buccal) grooves are not likely to be deep
    or fissured.
   The typical third molar will have two roots
    (mesial and distal). These will usually be shorter        M
    and curved more toward the distal with a higher       D
    degree of inclination relative to the occlusal
    plane. The roots may be separated or fused for
    all or part of their length.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Lingual




   From the lingual aspect it will be
    noted that the lingual cusps are likely
    to be more pointed than facial cusps.
    Otherwise, this surface presents a
    relatively smooth and convex contour.
                                                  D
                                              M
    Permanent Mandibular Third Molar – Mesial
 The mesial view resembles that
  of the mandibular second molar
  except that the facial and lingual
  cusps are more nearly the same
  height. Accordingly, the cervical
  line crosses the surface more
  horizontally.
 The roots are shorter; therefore, the
  facial and lingual outlines                   L
                                          F
  converge at a faster rate toward the
  apex. The root apex is more
  pointed.
    Permanent Mandibular Third Molar – Mesial
 The mesial view resembles that of
  the mandibular second molar
  except that the facial and lingual
  cusps are more nearly the same
  height. Accordingly, the cervical
  line crosses the surface more
  horizontally.
 The roots are shorter; therefore,
  the facial and lingual outlines               L
                                       F
  converge at a faster rate toward
  the apex. The root apex is more
  pointed.
    Permanent Mandibular Third Molar – Distal

   The anatomical appearance
    from the distal aspect will be
    somewhat similar to the distal
    view of either a mandibular
    second molar or a mandibular
    first molar except for the size
    and length of the root. Also,
    variations will occur depending             F
                                       L
    on whether the tooth has four or
    five cusps.
    Permanent Mandibular Third Molar – Occlusal
   This tooth varies greatly in morphology
    and is second only to the maxillary third
    molar in this respect.
   Most mandibular third molars crowns
    conform to the characteristics of a mandibular
    second molar in the number and arrangement
    of the four cusps (Type I). They also present
    a “4+” groove pattern. Other mandibular
    third molars (Type II) will have five cusps and
    a groove pattern similar to a mandibular first
    molar. Both types will usually have a more
    rounded and narrower distal outline than
    either a mandibular first or second molar.        M
   The occlusal anatomy often presents many
                                                          D
    supplemental grooves radiating from the basic
    developmental grooves.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Occlusal
   This tooth varies greatly in morphology and is
    second only to the maxillary third molar in
    this respect.
   Most mandibular third molars crowns
    conform to the characteristics of a
    mandibular second molar in the number
    and arrangement of the four cusps (Type
    I). They also present a “4+” groove
    pattern. Other mandibular third molars
    (Type II) will have five cusps and a groove
    pattern similar to a mandibular first molar.
    Both types will usually have a more
    rounded and narrower distal outline than         M
    either a mandibular first or second molar.           D
   The occlusal anatomy often presents many
    supplemental grooves radiating from the basic
    developmental grooves.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Occlusal
   This tooth varies greatly in morphology and is
    second only to the maxillary third molar in
    this respect.
   Most mandibular third molars crowns
    conform to the characteristics of a mandibular
    second molar in the number and arrangement
    of the four cusps (Type I). They also present
    a “4+” groove pattern. Other mandibular
    third molars (Type II) will have five cusps and
    a groove pattern similar to a mandibular first
    molar. Both types will usually have a more
    rounded and narrower distal outline than
    either a mandibular first or second molar.        M
   The occlusal anatomy often presents many
                                                          D
    supplemental grooves radiating from the
    basic developmental grooves.
   Mesial contact area: Center of the middle 1/3
    Permanent Mandibular Third Molar – Occlusal
   This tooth varies greatly in morphology and is
    second only to the maxillary third molar in
    this respect.
   Most mandibular third molars crowns
    conform to the characteristics of a mandibular
    second molar in the number and arrangement
    of the four cusps (Type I). They also present
    a “4+” groove pattern. Other mandibular
    third molars (Type II) will have five cusps and
    a groove pattern similar to a mandibular first
    molar. Both types will usually have a more
    rounded and narrower distal outline than
    either a mandibular first or second molar.        M
   The occlusal anatomy often presents many
                                                          D
    supplemental grooves radiating from the basic
    developmental grooves.
   Mesial contact area: Center of the middle
    1/3
Permanent Mandibular Third Molar - Summary
   Single facial groove
   Cusps equal in height                                          Facial
   Short, distally inclined roots

   Lingual surface relatively smooth with a convex contour
   Short, distally inclined roots                                 Lingual

   Facial & lingual cusps essentially the same height
   Short root with facial & lingual aspects rapidly converging
    toward the apex                                                Mesial

   Facial & lingual cusps essentially the same height
   Short root with facial & lingual aspects rapidly converging
    toward the apex                                                 Distal
   Ovoid shape
   Type I: “4+” groove pattern
   Type II: 5 cusps resembling mandibular 1st molar              Occlusal
Mandibular Third Molar
Key Points
 Extreme variations
  in form
 Usually more
  rounded from any
  viewpoint
 Frequently missing
 Often impacted
Mandibular Third Molar
Key Points
 Extreme variations
  in form
 Usually more
  rounded from any
  viewpoint
 Frequently missing
 Often impacted
Mandibular Third Molar
Key Points
 Extreme variations
  in form
 Usually more
  rounded from any
  viewpoint
 Frequently missing
 Often impacted
Mandibular Third Molar
Key Points
    Wide MD
    Rounded features
    3 occlusal fossae
    Shallow central pit
    4 cusp or 5 cusp
     varieties
Mandibular Third Molar
Variant Occlusal Forms




     Type I- 4 cusps   Type II- 5 cusps
Mandibular Third Molar
Key Points
    Shallow grooves
    Shallow fossae
    Cusp heights
    Geometric shapes
    CEJ curvature

				
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