Adjustment of Occlusion Rims & VD

1
Maxillo - Mandibular Relationships
2
Occlusal Vertical Dimension

• Amount of separation between mandible maxilla
  when denture teeth are in contact

3
Hinge Axis Location

• Use earbow to record relationship of the maxilla
  to the transverse horizontal axis
• Locate an anterior reference point

4
Centric Position

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

5
Programming the ArticulatorProtrusive
Relationship

• Simulate relationship of maxilla to mandible in
  excursions
• Denture teeth set in harmonious relationship for
  function

6
Record Bases (Base plates) and Occlusion Rims

• They simulate teeth and help in establishing
  vertical dimension and centric relation
• Used to relate casts on an articulator
• Record bases simulate the finished denture base

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Occlusion rims

• Definition occlusion rims are occluding
  surfaces constructed on record bases or permanent
  denture bases to be used in recording jaw
  relations and for arranging teeth.
• Requirements
• The position should be in the anticipated
  position of the artificial teeth.
• It must be securely attached to the base.
• The occlusal surface must be smooth and flat.
• It should be contoured to support the lip and
  cheeks accurately.
• All the surfaces should be smooth.

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Occlusion rims

• The occlusion rims are used
• To establish the level of the occlusal plane.
• To establish the arch form.
• To record the max-man relations.
• For arrangement of the teeth.

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Record Bases and Occlusion Rims

• Wax occlusion rims simulate the position of the
  teeth

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Record Bases Occlusion Rims

1. Temporary base
2. Permanent base

• Occlusion rims slightly bulkier
• Provide additional stability during record making

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Temporary record bases

• Temporary record bases
• They are discarded and replaced by denture base
  material, once their role in establishing jaw
  relation, teeth arrangement and try in is
  complete.
• Types of temporary record bases
• Shellac base plate
• Reinforced shellac base plate
• Cold cure acrylic resin
• Visible light cure acrylic resin
• Vacuum formed vinyl and polystyrene
• Base plate wax

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Visible Light cured acrylic resin
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Permanent base

• Permanent record bases
• They are not discarded and become part of the
  actual base of the finished complete denture.
• Types of permanent record bases
• Heat cure acrylic resin
• Gold
• Chromium-cobalt alloy
• Chromium-nickel alloy

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Record Base Retention

• Required for record making and phonetic tests
• Inaccurate if loose
• Use denture adhesive if slightly loose
• Pronounced looseness - REMAKE

15
Record Base Retention

• Causes of Poor Retention
• Poor adaptation of resin to cast
• Over- or under-extension
• Excessive block-out

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Arbitrary adjustment of maxillary occlusion Rims

• The anterior wax rim height is 20-22mm
• The posterior wax rim height is 16-18mm.
• The width of the anterior rim is approximately 3-
  5mm.
• The width of the occlusal rim in the posterior
  region is approximately 8- 10mm.
• The occlusal rim is properly sealed to the
  baseplate without any voids.
• The posteriors of the occlusion rims are cut at a
  30º angle to the occlusal plane

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Arbitrary adjustment of maxillary occlusion Rims
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Arbitrary adjustment of mandibular occlusion Rims

• The anterior wax rim height is 16-18mm
• The posterior wax rim height covers 2/3 of the
  retromolar pad.
• The width of the anterior rim is approximately 3-
  5mm.
• The width of the occlusal rim in the posterior
  region is approximately 8- 10mm.
• The occlusal rim is properly sealed to the
  baseplate without any voids.

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Arbitrary adjustment of mandibular occlusion Rims
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Arbitrary adjustment of Occlusion Rims

• Maxillary rim slightly facial to ridge to
  compensate for residual ridge resorption to
  support upper lip

20-22 mm
18-22 mm
2/3 retromolar pad
16-18 mm
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Maxillary Occlusion Rim Adjustment

• Maxillary rim slightly facial to compensate for
  ridge resorption

22
Use a Hot Scapel Blade
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Use a Hot Wax Former
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1- Proper lip support
Maxillary Occlusion Rim Adjustment
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2- Anterior height adjustment
Maxillary Occlusion Rim Adjustment

• Anterior height 1-2 mm below the lip at rest/when
  the patient slightly smiles

26
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
gt30mm 0
Sex Age Female Male Youn
g 2 1 Middle 1 0 Old 0 -1
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Maxillary Occlusion Rim Adjustment

• Touches wet line of lower lip when F or V
  sounds
• Count 50-60

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Maxillary Occlusion Rim Adjustment

• Lips should be unstrained

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J plane fox plane
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3- Occlusal plane orientation
Maxillary Occlusion Rim Adjustment

• Mediolaterally the occlusal plane parallels the
  interpupillary line
• Fox plane can be used

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3- Occlusal plane orientation
Maxillary Occlusion Rim Adjustment

• Occlusal plane parallel to the ala-tragus line

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Maxillary Occlusion Rim Adjustment
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Mandibular Occlusion Rim Adjustment

• Centered over the ridge to maximize stability

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Mandibular Occlusion Rim Adjustment

• Posteriorly, the occlusion rim intersects 1/2 -
  2/3 up the retromolar pad

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Mandibular Occlusion Rim Adjustment

• Anterior height even with the corners of the
  mouth when the lip is relaxed

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Mandibular Occlusion Rim Adjustment

• 1-2 mm horizontal overjet in anterior posterior
  in centric position

37
Mandibular Occlusion Rim Adjustment

• Unstrained lips
• Vermilion border showing

38
Occlusal Vertical Dimension (OVD)

• Distance between maxilla mandible when teeth or
  wax rims contact in centric position

39
Physiologic Rest Position (PRP)vertical
dimension of rest (VDR)

• The vertical dimension of rest is a measurable
  distance, a repeatable reference within an
  acceptable range a useful reference when
  establishing the vertical dimension of occlusion
  (VDO).

40

• Factors to be considered for rest position as a
  reference are
• 1) The position of the mandible is influenced by
  gravity, so, mandibular positions are postural.
• 2) Rest position is a relaxed position of the
  mandible.
• 3) Rest position is a position in space, which
  cannot be maintained for definite periods of
  time.
• 4) Space between the teeth is essential when the
  mandible is at rest.

41
Physiologic Rest Position (PRP)vertical
dimension of rest (VDR)

• At rest, lips barely touching
• Occlusion rims should not touch

Intraorally no contact
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Interocclusal Distance (ID) orfree way space
(FWS)

• Space between wax rims at physiologic rest
  position
• Usually 2-4 mm

43
Establishing Occlusal Vertical Dimension

• ID OVD PRP
• (FWS OVD RVD)

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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

45
Establishing Occlusal Vertical Dimension

• Check with three techniques to ensure acceptable
  OVD
• No one technique 100 correct

46
Patient sitting bolt upright

• Soft tissue position affected by posture
• Seat the patient in a comfortable upright
  position unsupported by a head rest

47
Measurements OVD PRP

• Use external points for ease of measurement
• Small dots under columnella mid-symphisis
• Use Boley Gauge, not ruler

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Measuring Occlusal Vertical Dimension

• Measure the distance between dots
• At PRP
• At OVD
• Difference is ID
• Measurements change each day (position of dots)

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Measuring Physiologic Rest Postion

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

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Measuring Occlusal Vertical Dimension

• Open and close until rims touch
• Measure distance between dots (OVD)
• Measurement will be different each appointment

51
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

52
Establishing OVDPhonetics Test

• Closest Speaking Space
• Confirms OVD
• Sibilant sounds ("s", "z", sh", ch")
• Rims should be at least 1 mm apart
• Dont worry about sounds yet

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Excessive OVDWax Rims Too High

• Insufficient interocclusal distance
• Remove wax from one or both of the rims

54
Wax Rim Adjustment at OVD

• Flat even contact along entire occlusal surface
• EXTREMELY CRITICAL
• If uneven contact, patient may be forced into
  eccentric position

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Adjusting Wax Rim Height

• Scribe lines parallel to the opposing occlusal
  rim
• Use as a guides during reduction

56
Eliminating Record Base or Wax Rim Interferences

• Patient in Centric Position
• Scribe three widely separated lines between
  maxillary mandibular rims

57
Establishing OVD

• Remove, superimpose the lines
• Eliminate contacts between record bases, record
  base/occlusion rims

58
Adjusting Occlusion Rims

• Continue to adjust the rims until
• interocclusal distance is 2-4 mm
• even contact along rims in centric position.

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Excessive Occlusal Vertical Dimension

1. Sore muscles
2. Soft tissue sore spots
3. Rapid bone resorption
4. Dentures click during speech

60
Inadequate Occlusal Vertical Dimension

1. Collapsed Appearance - chin too close to the nose
   or protruding jaw
2. Fatigue when chewing
3. Sore muscles or joints
4. Soreness at the corner of the mouth (Angular
   cheilitis)