1. Maxillo-Mandibular Relation (MMR) involves creating and outlining denture forms, recording intermaxillary relations in centric relation, and selecting teeth.
2. Recording intermaxillary relations in centric relation involves guiding the patient to retruded contact position and making impressions to capture the mandibular arc of closure.
3. Selection of teeth involves choosing anterior teeth to restore lip contours and smile lines and posterior teeth types and shades based on facial features and patient preferences.
2. Learning objectives:
to understand what is the component parts of the maxillo-mandibular
relation and it is role in the success of the complete denture treatment.
to understand the clinical steps of maxillo-mandibular relation in complete
denture treatment.
to uderstand the theory of the face-bow transfer , it’s indication & clinical
application procedure.
4. MMR is The clinical stage following the visit where Definitive (final
impressions) are recorded.
Occlusal rims should be
ready to accomplish the
MMR record.
5. MMR stage is composed of three component
parts:
1. Creating and outlining the form of the dentures
2. Recording of intermaxillary relations
3. Selection of teeth.
7. Objective:
• to design and orient the polished surface of the denture to be
in harmony with the physiological function of the tongue, lips
and cheeks.
• the polished surface should occupy a position of equilibrium
among these groups of muscles and it is frequently referred to
as the neutral zone.
8. Clinical steps in Creating and outlining the form of the
maxillary denture:
Prior to inserting the rim into
the mouth, ensure that the rim
is well adapted to the master
cast
Remember that the technician constructed the occlusal rims based on
average values and it is the role of the dentist to create & outline the
form of the denture by adding or removing wax for each individual
patient.
9. Clinical steps in Creating and outlining the form of
the maxillary denture:
First clinical step is to ensure that
the infra-nasal tissues are
harmonious with the soft tissues
of the middle third of the face.
Failure to do this may affect the
form and length of the upper
lip, by raising the lip
inappropriately.
10. Clinical steps in Creating and outlining the form of the
maxillary denture:
Confirm that the upper lip is adequately supported.
This should result in restoration of the
- vermilion border
- the philtrum
12. Determine the position of the incisal point
relative to the resting lip:
the incisal level of the upper rim is 2 mm
inferior to the resting upper lip.
In contrast, a 70-year-old patient might be
best suited by having the incisal point level
with the resting lip
Younger patients may reasonably be expected
to show 4–5 mm of tooth beneath the resting
lip.
13. Antero-posterior verification of the placement of the incisal point
may be achieved by asking the patient to say a word containing a
labiodental sound eg ‘fish’ .
In general terms, the incisal point should correspond to the vermilion
border of the lower lip
14. ‘Fox Plane’ device placed against the maxillary
occlusion rim. This should be parallel to the
interpupillary line.
Determine the upper occlusal plane
Fox’s plane device used
The posterior occlusal plane should be
parallel to the ala-tragus line (Camper’s
Plane).
Determine the posterior occlusal plane
15. Extend dental floss from
the inner canthus of the
eye, via the lateral border
of the alar cartilage (with
the patient smiling) onto
the incisal edge of the
upper rim
Determine the position of the mid points of
the upper canine teeth
Using the canine tips as a
reference point, the buccal form of
the upper rim may be moulded by
reducing the inferior borders of
the posterior rims by 3° to 5°.
This procedure creates what are known as the buccal
corridors and creates a more natural smile
16. The following should be scribed clearly
on the anterior aspect of the rim:
Centre line
High smile line
Canine points
19. Vertical Relation
Important terms
Vertical dimension of rest: (RVD)
also known as Physiologic rest
position
Vertical Dimension of Occlusion:
(OVD)
Interocclusal Distance
Formerly known as “ freeway
space”
20. Vertical Dimension of Occlusion:
The position of the jaws when the
natural teeth are in maximum
intercuspation.
May become “less” (nose closer to
chin) if posterior support is lost or
natural teeth wear quickly.
With complete dentures
VDO “lost” as denture teeth wear
and ridges resorbs.
21. Vertical Dimension of Rest Position
When “All muscles that open and close the jaw are in a state of
minimal tonic contraction”.
• VDO is usually about 2-4mm less than VDR
• Difference (VDR-VDO) is the interocclusal distance (free way
space)
• This space between the teeth is necessary for comfort
• This is the best starting point in establishing the correct VDO for a
new set of dentures
23. Increase in OVD
“Patient mouth is opened excessively”
Loss of interocclusal distance
Denture teeth in contact at rest
Soreness of mucosa over ridges
Potential for accelerated resorption
Soreness of facial muscles : “Tired face”
Soreness of TMJ
Difficulty with eating and speech
Clicking dentures, no room to chew
24. Decrease in OVD
“Patient’s mouth has over closure”
Collapsed Appearance - chin too close to the
nose or protruding jaw
Fatigue when chewing
Sore muscles or joints
25. Establishing Occlusal Vertical Dimension
1. Measure difference between RVD & OVD
2. Tactile sense and patient-perceived comfort.
3. Phonetics tests “Closest Speaking Space”
Patient sitting upright
29. Phonetics tests “Closest Speaking Space”
Closest Speaking Space confirms OVD
Sibilant sounds ("s", "z", sh", ch")
Rims should be at least 1 mm apart.
Don’t worry about sounds quality yet.
30. Horizontal Relationships
The generally agreed position for recording the antero-
posterior position of the mandible relative to the maxilla is that
of the retruded contact position (RCP).
RCP=CR (centric relation)
31. Centric relation:
The maxillomandibular relationship in
which the condyles articulate with the
thinnest avascular portion of their
respective disks with the complex in the
anterior-superior position against the
slopes of the articular eminencies.
32.
33. Why centric relation ...?
it is the only repeatable , recordable & reproducible position in
the edentulous patient.
abnormal contact between opposing dentures when set up in
other than the retruded relationship results in denture
instability.
the apparatus used for reproducing relevant jaw movements
(the articulator) operates from the retruded position.
34. Registration of the centric relation:
Guiding the patient into retruded contact position:
Ask the patient to relax
and guide the mandible
into the centric relation.
35. Guiding the patient into retruded contact position
Ask patient to curl back the
tongue to touch the posterior
border of the palatal
baseplate and then close
together (swallow).
36. Guiding the patient into retruded contact position
Ask the patient to push the
mandible forward while
applying gentle counter
resistance to the chin.
Train the patient to bite into retruded contact position prior to
registration.
Draw a check marks on the occlusal rims to ensure reproducibility of
the mandibular closure pattern.
37. Registration of the centric relation:
Make a 3mm notches into the
maxillary occlusal rims at about the
2nd premolar region bilaterally .
2 mm of wax are removed from
the mandibular occlusal rims at the
opposing region.
Register the centric relation using a
bite registration material.
38. Orientation of the occlusal plane:
The use of a face bow registration fixes the
maxillary cast in the same three-
dimensional plane in relation to the
condyles as exists in the patient and
thereby reproduces the patient's arc of
closure.
Capturing the correct mandibular arc of
closure is probably the most compelling
rationale for the use of a semi-adjustable
articulator.
39. 1. Two posterior references approximating each of the TMJ (external
auditary meatus)
2. An anterior reference point to relate the maxilllary cast vertically to
the selected horizontal reference plane.
A facebow relates the maxillary arch to the axis of the
condylar hinge using tripod localisation:
40. i) Kinematic facebow
ii) Arbitrary Facebow
• When facebow is not used to relate the maxillary cast to the
approximated starting positions of the condyles, the resulting arcs
of movement may differ from the patient to the articulator.
• This may cause restorations fabricated on the articulators to have
potential occlusal errors.
43. ▪ Selection of upper anterior teeth.
▪ Selection of lower anterior teeth.
▪ Selection of posterior teeth types and moulds.
▪ Selection of shade(s) of the anterior and
posterior teeth.
44. Selection of upper anterior teeth
Pre-extraction record:
Photograph
Relate canine points to pupils.
Relate canine points to inter-alar width.
Relate six anterior teeth to smile line.
Radiograph
Cast of arch
Relative of similar facial appearance.
45. Post-extraction record:
Central Incisor restore philtrum
Central incisor restore
vermillion Border
Incisal point and smile line
determine height of tooth
Position of canine points.
Relate to inner canthus of the
eyes and inter-alar width (smiling).
46. Selection of lower anterior teeth
Lower anterior teeth selected to be harmonious with upper teeth.
47. Selection of posterior teeth types and
moulds
Posterior tooth moulds are of three
types:
a) Posterior teeth which have cusps.
b) Posterior teeth which have no
cusps.
c) Hybrid mould ie teeth which are
modified to obtain the benefits of
a) and b)
48. Selection of teeth shade(s)
Remember that patient acceptance is the main factor.
50. References:
Davies SJ, Gray RM, McCord JF. Good occlusal practice in
removable prosthodontics (2001).Br Dent J.10;191(9):491-4, 497-502.
Grant A. A., Heath J. R. & McCord J. F. (1994). Complete prosthodontics problems
diagnosis and management. Mosby.
Mc Cord J F, Grant AA(2000).Registration: stage I--creating and outlining the form of
the upper denture. Br Dent J. 27;188(10):529-36.
Mc Cord J F, Grant AA(2000). Registration: stage II--intermaxillary relations.
Mc Cord J F, Grant AA(2000). Registration: stage III—selection of teeth.
The glossary of prosthodontic terms (2005) J Prosthet Dent ;94(1):10-92.
Zarb Bolender (2004) Prosthodontic treatment for edentulous patients. Complete
dentures and implant-supported prostheses. Mosby. Twelfth Edition.
Br Dent J. 24;188(12):660-6.