Recording Maxillo-mandibular Relationships by suchenfz

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									Maxillo - Mandibular
   Relationships

 Occlusal Vertical Dimension
  And Hinge Axis Relation
Occlusal Vertical Dimension
Amount of
separation
between
mandible &
maxilla when
denture teeth
are in contact
        Hinge Axis Location
• Use earbow to
  record relationship
  of the maxilla to the
  transverse
  horizontal axis
• Locate an anterior
  reference point
          Centric Position

• Relationship of
  maxilla and mandible
• Anterior/posterior &
  medio-lateral)
• Maximum
  intercuspation of the
  denture teeth
Programming the Articulator
         Protrusive Relationship

• Simulate relationship
  of maxilla to mandible
  in excursions
• Denture teeth set in
  harmonious
  relationship for
  function
    Record Bases (Baseplates)
      and Occlusion Rims
• Used to relate casts
  on an articulator
• Record bases
  simulate the
  finished denture
  base
          Record Bases and
           Occlusion Rims

• Wax occlusion
  rims simulate
  the position of
  the teeth
   Record Bases & Occlusion
            Rims
• Occlusion rims
  slightly bulkier
• Provide additional
  stability during
  record making
  Record Base Retention

• Required for record making and
  phonetic tests
• Inaccurate if loose
• Use denture adhesive if slightly loose
• Pronounced looseness - REMAKE
   Record Base Retention
• Causes of Poor Retention
  – Poor adaptation of resin to cast
  – Over- or under-extension
  – Excessive block-out
    Arbitrary Adjustment of
        Occlusion Rims
• Adjust separately using
  average dimensions:
     Maxillary - 23 mm
     Mandibular - 18 mm
• ‘Starting Point’
• Fairly rapid adjustment
   ~ 15 minutes per arch
Use a Hot Scapel Blade
Use a Hot Wax Former
    Maxillary Occlusion Rim
          Adjustment
• Maxillary
  rim slightly
  facial to
  compensate
  for ridge
  resorption
    Maxillary Occlusion Rim
          Adjustment
• Anterior
  height 1-2 mm
  below the lip
  at rest/when
  the patient
  slightly smiles
Wax rim/tooth display can be
adjusted with sex, age, and lip
length        (Vig: JPD 1978).


  Lip Length Incisal Display
    10-20mm        3-4mm
    20-25mm         2mm

    26-30mm         1mm

    >30mm            0

              Sex & Age
       Female         Male
Young +2              +1
Middle +1              0
Old     0             -1
    Maxillary Occlusion Rim
          Adjustment
• Touches wet
  line of lower
  lip when ‘F’ or
  ‘V’ sounds
• Count ‘50-60’
     Maxillary Occlusion Rim
           Adjustment
•   Lips should be unstrained
•   Naso-labial angle ≈ 90°
•   Philtrum depressed
•   Vermilion border showing
    Maxillary Occlusion Rim
          Adjustment


• Occlusal plane
  parallel to the
  ala-tragus line
    Maxillary Occlusion Rim
          Adjustment
• Mediolaterally
  the occlusal
  plane parallels
  the pupils
• Fox plane can be
  used
 Mandibular Occlusion Rim
       Adjustment

• Centered
  over the
  ridge to
  maximize
  stability
  Mandibular Occlusion Rim
        Adjustment
• Posteriorly, the
  occlusion rim
  intersects 1/2 - 2/3 up
  the retromolar pad
  Mandibular Occlusion Rim
        Adjustment
• Anterior height
  even with the
  corners of the
  mouth when the
  lip is relaxed
 Mandibular Occlusion Rim
       Adjustment
• 1-2 mm
  horizontal
  overjet in
  anterior &
  posterior in
  centric
  position
    Mandibular Occlusion Rim
          Adjustment

• Unstrained lips
• Vermilion
  border showing
    Occlusal Vertical Dimension
                    (OVD)

• Distance between
  maxilla & mandible
  when teeth or wax
  rims contact in centric
  position
Physiologic Rest Position (PRP)
   • At rest, lips barely
     touching
   • Occlusion rims
     should not touch




       Intraorally no contact
 Interocclusal Distance (ID)

• Space between wax rims at
  physiologic rest position
• Usually 2-4 mm
Establishing Occlusal Vertical
          Dimension

      PRP = ID + OVD
       Establishing
Occlusal Vertical Dimension

1. Measure difference between PRP & OVD
2. Feel to ensure movement of mandible
3. Phonetics tests ‘Closest Speaking Space’

         Patient sitting bolt upright
       Establishing
Occlusal Vertical Dimension

 • Check with three techniques to
   ensure acceptable OVD
 • No one technique 100% correct
Patient sitting bolt upright
 Soft tissue position affected by posture
             Measurements
                  OVD & PRP


• Use external points for
  ease of measurement
• Small dots under
  columnella & mid-
  symphisis
• Use Boley Gauge, not
  ruler
Measuring Occlusal Vertical
       Dimension
  • Measure the distance between
    dots
    – At PRP
    – At OVD
    – Difference is ID
  • Measurements change each day
    (position of dots)
        Measuring
  Physiologic Rest Postion

• Open and close until lips barely touch
  - Physiologic Rest Position (PRP)
• Measure distance between dots
        Measuring
Occlusal Vertical Dimension

• Open and close until rims touch
• Measure distance between dots (OVD)
• Measurement will be different each
  appointment
             Establishing OVD
      Feeling for Interocclusal Distance
• Close until lips barely
  touch - PRP
• Place finger on chin
• Look away
• Patient closes until rims
  touch (OVD)
• Feel for movement of the
  mandible
       Establishing OVD
           Phonetics Test

•   Closest Speaking Space
•   Confirms OVD
•   Sibilant sounds ("s", "z", sh", ch")
•   Rims should be at least 1 mm apart
•   Don’t worry about sounds yet
           Excessive OVD
          Wax Rims Too High
• Insufficient interocclusal distance
• Remove wax from one or both of the rims
   – Use large wax formers
   – #5 & #7 wax spatulas
   – Red-handled knife
   – Bunsen burner and torch
  Wax Rim Adjustment at OVD

• Flat even contact along
  entire occlusal surface
• EXTREMELY
  CRITICAL
• If uneven contact, patient
  may be forced into
  eccentric position
   Adjusting Wax Rim Height
• Scribe lines
  parallel to the
  opposing
  occlusal rim
• Use as a guides
  during
  reduction
    Eliminating Record Base or
      Wax Rim Interferences

• Patient in Centric
  Position
• Scribe three
  widely separated
  lines between
  maxillary &
  mandibular rims
          Establishing OVD
• Remove,
  superimpose the
  lines
• Eliminate contacts
  between record
  bases, record
  base/occlusion
  rims
  Adjusting Occlusion Rims

• Continue to adjust the rims until:
  – interocclusal distance is 2-4 mm
  – even contact along rims in centric
    position.
Excessive Occlusal Vertical
        Dimension
• Sore muscles
• Soft tissue sore
  spots
• Rapid bone
  resorption
• Dentures click
  during speech
    Inadequate Occlusal Vertical
            Dimension

• Collapsed Appearance -
  chin too close to the nose
  or protruding jaw
• Fatigue when chewing
• Sore muscles or joints
        Hinge Axis Location
• Face-bow or
  ear-bow used
• Record
  relationship of
  maxilla to
  transverse
  horizontal hinge
  axis of mandible
        Hinge Axis

• Transferred to the articulator
• Important to prevent occlusal
  errors, particularly when
  cusped teeth are used in
  dentures.
Edentulous Bite Fork:
Allows patient to close
against the opposing
rim to stabilize the
record bases
Heat bite fork and imbed it
 centered and parallel the
      occlusal plane
                     Finger cots can be used
                     over ear pieces for
                     infection control




Patient can assist
with placement and
orientation in
external auditory
meatus
Orient in external
auditory meatus
                   Slide facebow onto
                   bitefork




   Extend nasion
support& tighten
                         Tighten center facebow
                         screw




Set and tighten nasion
nosepiece
Ball correctly placed inside slot will ensure full range of anterior/posterior
movement of the toggle assembly.




                                                      Ball placed in slot
                         Attach the Quick Lock
                         Toggle Assembly to the
                         bite fork.




Tighten the Quick Lock
Toggle




                         Release the recordbase by
                         breaking the seal, and
                         removing the facebow.
Loosen and remove the
transfer jig from the
earbow
Place facebow support
on transfer jig and attach
to indirect mount.
Don’t use direct method
with indirect mount.
                          Remove incisal pin and set
                          the centric latch




Ensure front support on
your articulator
Indirect jig with record base on
           articulator
Place cast support and
maxillary mounting
plate
   Attach cast with
mounting plaster in two
        steps

								
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