Complete Denture Dent 482.01 and by 2wL3KzkF

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									Setting Anatomic Teeth
  The anterior teeth should not be positioned any
further forward than the depth of the labial vestibule,
determined by a line drawn from the depth of the
vestibule and perpendicular to a line drawn parallel to
the occlusal plane. The depth of the vestibule is the
fulcrum point and the further forward a tooth extends
beyond this point, the greater are the forces that tend
to dislodge the denture.
  The middle of the depth of the vestibule
should be recorded on the maxillary &
mandibular casts. The middle of the crest of
the mandibular ridge should also be recorded.
These are marked on the land areas because
the baseplate will cover the marks on the
ridge or in the vestibules.
  Next, mark the midline of the patient’s face
by placing a dot on the incisive papilla and
marking this midline on the maxillary anterior
land area, extending down the front of the cast.
The incisive papilla is a much more reliable
landmark for the midline than the labial frenum.
  Make a cut with a heated, sharp knife, at the midline in
the anterior wax rim. Cut all the way to the baseplate.
Make a similar cut just distal to the canine point. Remove
this section of wax in its entirety. Reduce the anterior
ridge of the maxillary baseplate to provide a little extra
space for the tooth, but reduce the tooth if necessary to
fit properly.
  Use a flat plate resting flush with the occlusion
rim to position the central incisor so that it
contacts the occlusal plane.
  Set the rest of the anterior teeth on the
right side according to the curve defined by
the plastic ruler. The labioincisal line angle of
the incisors should touch the ruler, as well as
the midbuccal surface of the canine.
  Use a flexible plastic ruler to verify that
the incisal portion of the tooth’s labial
surface is properly located and in contact
with the anterior curvature of the occlusion
rim.
  An anterior view of the maxillary anterior
teeth shows that only the lateral incisors do
not touch the occlusal plane as recorded by
mandibular wax rim. With the maxillary
anterior teeth set, record the patient’s
midline and set the mandibular anterior teeth.
  The maxillary cast is placed back on the articulator. A
quick look will show that the maxillary teeth are set on the
same plane that the mandibular occlusion rim occupies,
showing the value of having the maxillary and mandibular
rims made in intimate contact. If the maxillary teeth are
not on the same plane as the lower rim, they must be reset.
  Mark the midline of the mandibular ridge on the
mandibular wax rim and cut out a section representing the
right mandibular anterior teeth from the rim. Reduce the
thickness of the Triad baseplate from the middle of the
ridge to the labial to allow for easier setting of the
mandibular anterior teeth. A central incisor placed in this
space shows that considerable reduction must be made on
the cervico-lingual ridgelap surface before the tooth can be
set in position.
  Mark the midline of the mandibular ridge on the
mandibular wax rim and cut out a section representing
the right mandibular anterior teeth from the rim.
Reduce the thickness of the Triad baseplate from the
middle of the ridge to the labial to allow for easier
setting of the mandibular anterior teeth. A central
incisor placed in this space shows that considerable
reduction must be made on the cervico-lingual ridgelap
surface before the tooth can be set in position.
  Remove enough wax to allow setting most of the posterior teeth
and thin the baseplate to allow for their positioning. Leave a small
segment of the wax rim intact and clearly mark the midline to
facilitate the setting of the teeth anterior to it. After these
teeth are set, remove this pillar to allow the last tooth to be set,
and those teeth anterior to it will indicate the center of the
ridge.
  Check the position of the teeth to the center of
the ridge with a tongue blade used as a straight
edge. Once it is verified by your lab bench
instructor that this relationship is correct, you
may begin setting the teeth on the other side,
using the same steps for setting, sequencing, and
verification that were used on the other side.
  With all the mandibular teeth set, check the
occlusal plane with a flat metal plate to verify
that all the teeth contact the flat surface
evenly. Expect some changes because of the
shrinkage of the wax, which will shift the teeth
slightly. Correct any discrepancies before
moving on to setting the maxillary posterior
teeth.
  With all the mandibular teeth set, check to see
that all the teeth contact the flat surface of the
maxillary wax rim evenly. If these teeth contact
the wax rim evenly, begin setting the maxillary
posterior teeth.
  Remove the wax on one side of the maxillary
baseplate. A quick look will verify that the
maxillary posterior teeth should have plenty of
space to be set with little or no reduction. The
rim is left intact on the opposite side because
this will help you to maintain the location of the
occlusal plane.
  Set the teeth on the maxillary right side so that the
mesiolingual cusp of the maxillary first molar rests in the
central fossa of the mandibular first molar. Set the
teeth so that the buccal surfaces of the premolar(s) and
mesial cusp of the first molar line up with the mid-buccal
surface of the canine. The distobuccal cusp of the first
molar should deviate approximately 20o from this plane
and the second molar will fall along this plane.
If a maxillary second molar were set, the buccal
cusps should line up with a second plane that is
determined by the buccal surfaces of the maxillary
first molar. In this case, there was not room
enough to do so, because the opposing mandibular
tooth would have to be set on the incline of the
retromolar pad.
  Set the teeth on the maxillary right side so that the
mesiolingual cusp of the maxillary first molar rests in the
central fossa of the mandibular first molar. Then move it
up so that the distobuccal cusp is ½ mm off the flat
plane. If there were room to set a maxillary second
molar, its mesiobuccal cusp would be 1 mm off the flat
plane and its distobuccal cusp would be 1½ mm off the flat
plane.
  Adjust the occlusal surfaces of all posterior teeth
to contact their opposing counterparts properly.
Note: There is no vertical overlap of the anterior
teeth at this time. With the anatomical maxillary
posterior teeth properly positioned and having
established a compensating curve and in harmonious
centric occlusion with the anatomical mandibular
posterior teeth, the mandibular anterior teeth are
moved up to a point where the mandibular incisors
contact the maxillary central incisors in protrusive
and simultaneously with posterior teeth.
                                                 



  The mandibular molars are now adjusted so that they
contact the maxillary molars in their new positions. The
teeth are designed to fit together with the mandibular
teeth to the outside of a curve. If they are set flat,
there will be spaces between the maxillary molars. There
should be a definite mediolateral component (Curve of
Wilson in natural teeth) visible when looking from the
back of the articulator .
   The occlusal rims contoured to         The teeth properly set in the wax to
   hold the lips in proper position.       maintain desired labial fullness.




 The teeth set too far labially giving   The teeth set too far lingually giving
the lips a “pouched out”appearance.      the lips a “dished in” appearance.
  A            B                             C




  Maximum horizontal overlap is shown in illustration
B. If teeth are set as in A the mandibular
denture would be very unstable during function.
When vertical overlap is desired, the guide table
must be set to record the anterior guidance.
  The position of the natural central
incisors and their relationship to the
ridge.
   A ridge
immediately after
the removal of the
tooth. Red dotted
line indicates the
position of the
natural root.
   The direction of
resorption in the
maxillary anterior
ridge is up and
back. The solid
line identifies the
resorbed ridge.
The red dotted
line identifies the
original contour of
the ridge.
  One of the most
common errors in
tooth positioning is
positioning the teeth
over the ridge
without considering
the original position
of the natural teeth.
   The denture with teeth
set over the ridge is
superimposed over the
original position of the
natural teeth. The loss
of vertical dimension and
lip support, and the
inevitable resulting loss in
aesthetics, is readily
apparent.
  The anterior teeth should not be positioned any
further forward than the depth of the labial
vestibule, determined by a line drawn from the depth
of the vestibule and perpendicular to a line drawn
parallel to the occlusal plane. The depth of the
vestibule is the fulcrum point and the further
forward a tooth extends beyond this point, the
greater are the forces that tend to dislodge the
denture.
                                              Force
                                           increases
                                               with
                                            distance
                                            from the
                                            fulcrum.
   If the teeth are inclined anteriorly to compensate
for a Class II relationship, a load placed anterior to
the middle of the anterior vestibule will have the
same destabilizing effect on the lower denture as the
man on a seesaw.
           HANAU’S QUINT
Hanau described five factors (Hanau’s Quint)
that affect occlusal balance

   Condylar Inclination – We don’t change.

   Incisal Guidance – Not with dentures

   Occlusal Plane Inclination – Start with establishing
    plane parallel with Ala-Tragus line.

   Cuspal Inclination – 0o, 10o, 20o, 30o, 33o

   Compensating Curve – Set teeth (curve of Spee, curve
    of Wilson).
               HANAU’S QUINT

                               Condylar Inclination


                                       Compensating Curve


                                                      Incisal Guidance –
 Cuspal Inclination
                                                      Not in dentures.

 Occlusal Plane
 Inclination
  Cuspal inclination
+ Occlusal Plane Inclination
  Condylar inclination &
  Compensating Curve
Tooth Alignment


                  •Centrals
                  •Laterals
                  •Canines
    Maxillary Anterior Teeth




 The axial inclination of maxillary anterior
teeth in the ‘basic’ arrangement. When viewed
facially, all the anterior teeth are tilted
mesially, with the lateral incisor inclined the
most and raised about 1-2 mm above the plane.
  Maxillary Anterior Teeth
        Cuspid         Lateral




                           Central


  When viewed laterally, the incisors are
depressed at the cervical, with the lateral
incisor being the most depressed, and the
canine being straight with the long axis
perpendicular to the occlusal plane.
  Mandibular Anterior Teeth




  The axial inclination of mandibular anterior
teeth in the ‘basic’ arrangement. When viewed
facially, all the anterior teeth except the
central incisors are tilted mesially, with the
canine inclined the most.
  Mandibular Anterior Teeth
             Cuspid    Lateral   Central




 When viewed laterally, the mandibular
central incisors are depressed at the
cervical, the lateral incisor is straight, and
the canine is inclined lingual to the long axis.
  Antero-posterior positioning of anterior teeth
give support to the lips, cheeks, and other tissues
of the oral cavity.

  The replacement of artificial teeth in the
original position of the natural teeth frequently is
not stressed or simply overlooked and resorbed
residual ridges are used as the primary control of
tooth position.

  A resorbed residual ridge – because of what
may be extreme changes in shape and size – is a
questionable landmark for either functional or
esthetic tooth position.
  Three different approaches
to providing a denture on the
same patient. Note the
differences in the setting of
the teeth and the festooning.
The same mold of teeth was
used in each case.
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? Questions?
  Questions?
   Questions?

								
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