Maxillo Mandibular Relationships

1
Maxillo - Mandibular Relationships

• Occlusal Vertical Dimension
• And Hinge Axis Relation

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 (Baseplates) and Occlusion Rims

• Used to relate casts on an articulator
• Record bases simulate the finished denture base

7
Record Bases and Occlusion Rims

• Wax occlusion rims simulate the position of the
  teeth

8
Record Bases Occlusion Rims

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

9
Record Base Retention

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

10
Record Base Retention

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

11
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

12
Use a Hot Scapel Blade
13
Use a Hot Wax Former
14
Maxillary Occlusion Rim Adjustment

• Maxillary rim slightly facial to compensate for
  ridge resorption

15
Maxillary Occlusion Rim Adjustment

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

16
Wax rim/tooth display can be adjusted with sex,
age, and lip length (Vig JPD 1978).
Lip Length
Incisal Display
Sex Age Female Male Youn
g 2 1 Middle 1 0 Old 0 -1
17
Maxillary Occlusion Rim Adjustment

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

18
Maxillary Occlusion Rim Adjustment

• Lips should be unstrained

19
Maxillary Occlusion Rim Adjustment

• Occlusal plane parallel to the ala-tragus line

20
Maxillary Occlusion Rim Adjustment

• Mediolaterally the occlusal plane parallels the
  pupils
• Fox plane can be used

21
Mandibular Occlusion Rim Adjustment

• Centered over the ridge to maximize stability

22
Mandibular Occlusion Rim Adjustment

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

23
Mandibular Occlusion Rim Adjustment

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

24
Mandibular Occlusion Rim Adjustment

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

25
Mandibular Occlusion Rim Adjustment

• Unstrained lips
• Vermilion border showing

26
Occlusal Vertical Dimension (OVD)

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

27
Physiologic Rest Position (PRP)

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

Intraorally no contact
28
Interocclusal Distance (ID)

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

29
Establishing Occlusal Vertical Dimension

• PRP ID OVD

30
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

31
Establishing Occlusal Vertical Dimension

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

32
Patient sitting bolt upright Soft tissue position
affected by posture
33
Measurements OVD PRP

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

34
Measuring Occlusal Vertical Dimension

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

35
Measuring Physiologic Rest Postion

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

36
Measuring Occlusal Vertical Dimension

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

37
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

38
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

39
Excessive OVDWax 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

40
Wax Rim Adjustment at OVD

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

41
Adjusting Wax Rim Height

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

42
Eliminating Record Base or Wax Rim Interferences

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

43
Establishing OVD

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

44
Adjusting Occlusion Rims

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

45
Excessive Occlusal Vertical Dimension

• Sore muscles
• Soft tissue sore spots
• Rapid bone resorption
• Dentures click during speech

46
Inadequate Occlusal Vertical Dimension

• Collapsed Appearance - chin too close to the nose
  or protruding jaw
• Fatigue when chewing
• Sore muscles or joints

47
Hinge Axis Location

• Face-bow or ear-bow used
• Record relationship of maxilla to transverse
  horizontal hinge axis of mandible

48
Hinge Axis

• Transferred to the articulator
• Important to prevent occlusal errors,
  particularly when cusped teeth are used in
  dentures.

49
Edentulous Bite Fork Allows patient to close
against the opposing rim to stabilize the record
bases
50
Heat bite fork and imbed it centered and parallel
the occlusal plane
51
Finger cots can be used over ear pieces for
infection control
Patient can assist with placement and orientation
in external auditory meatus
52
Orient in external auditory meatus
53
Slide facebow onto bitefork
54
Tighten center facebow screw
Set and tighten nasion nosepiece
55
Ball correctly placed inside slot will ensure
full range of anterior/posterior movement of the
toggle assembly.
Ball placed in slot
56
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.
57
Loosen and remove the transfer jig from the earbow
58
Place facebow support on transfer jig and attach
to indirect mount. Dont use direct method with
indirect mount.
59
Remove incisal pin and set the centric latch
Ensure front support on your articulator
60
Indirect jig with record base on articulator
61
Place cast support and maxillary mounting plate
62
Attach cast with mounting plaster in two steps