3. INTRODUCTION
JAW RELATION is defined as any relation of the
mandible to maxilla.
Jaw relation is recorded to measure the extensibility
and movements permissible by the patients TMJ.
3 DIFFERENT TYPES:
1. Orientation jaw relation
2. Vertical jaw relation
3. Horizontal jaw relation
4. HORIZONTAL JAW RELATION
Horizontal jaw relation is the maxillomandibular
relation in a horizontal plane.
Described as relationship of mandible to maxilla in
the anteroposterior direction.
2 TYPES:
1) CENTRIC jaw relation
2) ECCENTRIC jaw relation
5.
6. CENTRIC RELATION
Def :The maxillomandibular relationship in which
condyles articulate with the thinnest avascular
portion of their respective disc with the complex in the
anterior superior position against the slopes of
articular eminences.
This position is independent of tooth contact.
This position is discernible when the mandible is directed
superiorly and anteriorly.
It is restricted to a purely rotary movement about the
transverse horizontal axis.
7.
8. 3 primary requirements:
1. To record the correct horizontal relationship of
mandible to maxilla
2. To expert equalized vertical pressure
3. To retain record in undistorted condition until the
cast have been accurately mounted on articulator
9. SIGNIFICANCE:
In case of dentulous patients proprioceptive impulses
are obtained from PDL.
In case of edentulous patients centric relation act as
proprioceptive centre to guide occlusal movements.
10. SALIENT FEATURES:
o Is a definite learned position
o Patient can voluntarily and reflexily return to this position.
o Can be recorded and repeated.
o On mounting the cast on articulator he anteroposterior relation of
maxillary and mandibular casts becomes a definite entity.
o This position can be verified.
o Is a reference point in recording maxillomandibular relations and a
starting point for developing occlusion.
11. RETRUDING THE MANDIBLE:
Mandible should be in the most posterior position while recording centric
relation.
Method:
Relax the patient
Try to bring his upper jaw forward while occluding on the posterior teeth.
Instruct the patient to touch the posterior border of the upper record base
with his tongue.
Mandibular occlusal rim should be tapped with a finger gently.this would
help patient automatically to retrude his mandible.
12.
13.
14. METHODS TO RECORD CENTRIC RELATION:
PHYSIOLOGICAL
tactile or inter occlusal check record method
Pressureless method
Pressure method
FUNCTIONAL
Needle house method
Patterson method
GRAPHIC
Intra oral
Extra oral
RADIOGRAPHIC METHOD
15. Physiologic method
Based on:
o Proprioceptive impulse of patient
o Kinethetic sense of mandibular movement
o Visual acuity and sense of touch of patient
1) Tactile sense or inter occlusal check record method.
Tentative jaw relation is recorded.
Ask the patient to retrude the mandible.
Casts are articulated based on this tentative record
16. INDICATIONS
Abnormally related jaws.
Displaceable flabby tissue.
Large tongue
Uncontrolled mandibular movements.
In patients already using a complete denture
18. PROCEDURE:
a) Recording tentative jaw relation:
) Maxillary occlusal rim inserted to patients mouth.
) Vertical dimension at rest is established.mandibular
occlusal rim inserted and reduced accordingly,
) Tentative centric relation recorded using tentative
jaw relations.artificial teeth are arranged.
19. b) Making the inter occlusal check record.
Upper and lower trial dentures are inserted into the
mouth.keep a piece of cotton to prevent contact of
opposing members.
Aluwax is added on the occlusal surface of teeth of
mandibular occlusal rim
Patient asked to retrude mandible and close on the wax
till tooth contact occurs.
Trial dentures removed and allowed to cool.
20.
21. 2)Static or pressureless method.
Nick notch method:
Patient asked to retrude mandible in position.
Upto 3mm of wax removed from mandibular occlusal
rimfrom the premolar region till the distal end
1 or 2 notches are cut on the corresponding area of maxillary
occlusal rim.
One nick is cut anterior to the notch,a V shaped valley
Nick:prevent lateral movement
Notch: anteroposterior movement
22. Nick and notch are lubricated with petroleum.
Prepared occlusal rim are inserted into patient’s mouth
and taught to close his mandible in maximum retruded
position.
Aluwax is placed on the trough created in mandibular
rim.
Mandibular occlusal rim is cooled and inserted into
patients mouth and closed in centric relation.
23.
24.
25. 3)Pressure method
Establish vertical dimension.
Upper occlusal rim inserted.lower occlusal rim is
fabricated by softening in water bath.
Insert it into patients mouth.
Patient asked to close mouth in centric relation on soft
wax in predetermined vertical dimension and then
articulated.
26.
27.
28. Functional method
Method utilise the the functional movements of jaws to record the centric relation.
Patient asked to perfprm border border movements such as protrusive and lateral
excersion movement.
a) Needle house method
) Fabrication of occlusal rim made from impression compound
) Four metal beads or styli are embedded into premolar and molar areas of
maxillary occlusal rim.
) Occlusal rim inserted into patients mouth and asked to close occlusal rim and
make protrussive,retrussive ,right and left movement of mandible.
) When movements are made “diamond shaped marking pattern rather than a line
is formed on the mandibular occlusal rim.
31. b)Patterson method
Occlusal rim made of modelling wax.
In trench or trough is made along the length of
mandibular occlusal rim.
A mixture of carborundum and dental plaster is loaded
into the trench.
Perform mandibular movement till predetermined
vertical dimension.
Movement generates compensative curves in plaster
32.
33. Graphic method
The graphic method record a tracing of mandibular
movements in one plane
2 types:
1) Arrow point tracing
2) Pantograph
Arrow point tracing is a graphic record measured across single
plane
Pantogaph is measured three dimensionally.
34.
35. Factors to be considered while carrying out
tracing
1. Stability of denture base
2. Resistance of rims
3. Difficulty in placing central bearing device
4. Height of residual alveolar ridge
5. Tongue interferance
6. Efficiency of recording device
7. Lack of coordinated movements
36. Arrow point tracing or gothic arch tracer
Made using gothic arch tracers
Recorded in horizontal plane.
Consists of central bearing device:a device that provide central point of
bearing or support between the maxillary & mandibular dental arches.
consists of contacting point attached to one dental arch and plate attached
to opposing dental arch
Plate provide surface on which the tracing of mandibular movements is
recorded.
Consists of:CENTRAL BEARING POINT & CENTRAL BEARING PLATE.
37.
38.
39.
40. TYPES OF ARROW POINT TRACERS:
1) INTRA ORAL TRACING POINT:
) Central bearing device is located intra orally.
) Tracer is placed within the mouth.
) Central bearing point & plate is inserted into patients mouth.
) Central bearing point is adjusted such that it contact the central bearing
plate at predetermined vertical dimension.
) Ask to make anteroposterior and lateral movements.
) Central bearing point will draw the tracing pattern on central bearing
plate
) Tracing should resemble an arrow point with a sharp apex.
41.
42. 2)EXTRA ORAL POINT TRACER:
Concept similar to intra oral tracer.
Additionally have an attachment that project outside mouth.
Record bases attached to recording devices inserted in patients mouth.
Central bearing point is retracted to conduct training exercises.
Recording plate which projects extra orally is coated with precipitated
chalk and denatured alcohol.
Patient asked to perform all movements.
Examine for sharp apex.
43.
44.
45.
46. Points to be considered while doing graphic
tracing method
1. Displacement of record base may result from
pressure if central bearing points is off center when
mandible moves in eccentric relation to maxilla
2. If central bearing device is not used the occlusal
rims offer more resistance to horizontal movements
3. Difficult to stabilize record base against horizontal
forces on tissue that are pendulous
47. 4. Difficult to stabilize record base against horizontal
forces on residual ridges that have no vertical height
5. Difficult to stabilize record base with pt who have
awkward tongues
6. Recording device are not usually considered
compactible with physiologic stimulation in
mandibular movements
7. Tracing is not accepted unless a pointed apex is
developed
48. 8. Double tracing-lack of coordinated movement
9. It is made at predetermined vertical dimension of
occlusion.this harmonius centric relation with
centric occlusion and anteroposterior bone –bone
relation with tooth-tooth contact
10. Graphic method can reecord eccentric relation of
mandible to maxilla
11. Most accurate means
49. Pantographic tracing
A graphic record of mandibular movements in three planes
as registered by styli on recordable tables of a
pantograph,tracing of mandibular movement recorded on
plates in horizontal and sagittal planes.
Make the rim contact at desired vertical relationship.
Strips of celluloid paper are placed between the rim and
pulled out.patient is asked to close and restrain the celluloid
from slipping away,mandible goes to centric relation.
Softened wax is placed on mandibular occlusal rim and
patient is asked to bite in centric relation.
50.
51. ECCENTRIC JAW RELATION
“any relationship of mandible to maxilla other than
centric relation”
Include protrusive and lateral relations.
Help to adjust the lateral and horizontal condylar
inclination in the articulator.
Thus helps the articulator to reproduce eccentric
movements of mandible and establish balanced
occlusion.
Recorded using functional or tactile method.
52.
53. conclusion
The accurate determination , recording, and transfer
of jaw relation records from edentulous patient to
articulator is essential for restoring function, facial
apperance, and maintainance of patients health.
Un satisfactory maxillomandibular relations will
eventually lead to failure of complete denture
54. Referances
1. Essentials of complete denture prosthodontics 2nd
edition: Sheldon Winkler
2. Clinical dental prosthetics: H.R.B FENN: 2nd edition
3. Syllabus of complete denture : Charles M
Heartwell:4th edition
4. Textbook of prosthodontics : Deepak Nallaswami
