This document discusses centric jaw relation and methods for recording it. It defines centric jaw relation as the maxillomandibular relationship where the condyles are in the anterior-superior position against the articular eminence with the mandible directed superior and anteriorly. It describes various physiological, functional, and graphic methods for recording centric jaw relation, including tactile, needle house, Patterson's, and pantographic tracing methods. Pantographic tracing is highlighted as the most accurate three-dimensional graphic method.

1. FACULTY OF DENTAL SCIENCES
CENTRIC JAW RELATION
Dr Rajanikanth A.V
Professor
Department of Prosthodontics

2. INDEX
 INTRODUCTION
 SOME IMPORTANT TERMS.
 HORIZONTAL JAW RELATION.
 CENTRIC RELATION.
 REFERENCES.

3. INTRODUCTION
 Jaw relation is defined as,”Any relation of the mandible
to the maxilla.”
 Jaw relation is recorded to measure the extensibility
and the movements permissible by the patient’s
temporomandibular joint.
 There are three different types of jaw relations are;-
 Orientation jaw relation
 Vertical jaw relation
 Horizontal jaw relation.

4. SOME IMPORTANT TERMS…..
 Centric jaw relation-the most posterior relation of the
mandible to the maxilla at the established vertical
dimension.
 Eccentric jaw relation-any jaw relation other than
centric jaw relation.
 Orientation relation-The jaw relation when the
mandible is kept in its most posterior position,it can
rotate in the saggital plane around an imaginary
transverse axis passing through or near the condyles.”

5. Centric jaw relation.

6.  Vertical jaw relation- The length of the face as
determined by the amount of separation of the jaws.
 Horizontal jaw relation- It is the relationship of the
mandible to the maxilla in the horizontal plane or in
antero-posterior direction.

7. HORIZONTAL JAW RELATION
 It is the relationship of the mandible to the maxilla in a
horizontal plane.
 Horizontal jaw relation can be two types namely
 CENTRIC RELATION
 ECCENTRIC JAW RELATION.

8. CENTRIC RELATION
 It may be defined as the maxillomandibular
relationship in which the condyles articulate with the
thinnest avascular portion of their respective disc with
the complex in the anterior- superior position against
the slopes of the articular eminence. The position is
independent of tooth contact. The position is clinically
discernible when the mandible is directed superior
and anteriorly. It is restricted to a purely rotary
movement about the transverse horizontal axis.-GPT-5

9. Some salient features of centric relation.
 It is a definite learned position from which the
mandible can move to any eccentric position and
return back involuntarily.
 If the mandible has to move from one eccentric
position to another it should go to the centric relation
before advancing to the target eccentric position.
 Functional movements like chewing and swallowing
are performed in this position,because it is the most
unstrained position.

10.  The cast should me mounted in centric relation because it is
the point from which all the movements can be made or
simulated in the articulator.
 It is helpful in adjusting condylar guidance in an articulator
to produce balanced occlusion.

11. Methods of recording the centric jaw relation.
 PHYSIOLOGICAL METHODS:-
1)Tactile method
2)Pressure method.
 FUNCTIONAL METHOD:-
1)Needle house method
2)Patterson method.

12.  GRAPHIC METHODS:-
1)Intraoral
2)Extraoral

13. PHYSIOLOGICAL METHOD
TACTILE SENSE
 Also known as Interocclusal check record method.
 In this method, tentative centric jaw relation is
recorded by asking the patient to retrude the
mandible. The cast are articulated based on the
tentative jaw relation. Teeth arrangement is done and
an interocclusal registration is made. The tentative jaw
relation is verified with the interocclusal records and
errors are corrected.

14. Indications.
 Abnormally related jaws.
 Displaceable, flabby tissue.
 Large tongue.
 Uncontrollable mandibular movements.

15. PRESSURE METHOD.
 After establishing the vertical dimension,the upper
occlusal rim is inserted into the patients mouth.The
lower occlusal rim is fabricated to be of excess height.
 The entire lower occlusal rim is softened in a water
bath and inserted carefully into the patient’s mouth.
 The patient is asked to close the mouth in centric
relation.The patient is asked to close on the soft
wax.After the patients closes his mouth till the
predetermined vertical dimension,both the occlusal
rims are removed,cooled and articulated.

16. FUNCTIONAL METHOD.
NEEDLEHOUSE METHOD.
 It involves the fabrication of occlusal rims made from
impression compound.
 Four metal beads or styli are embedded into the
premolar and molars area of the maxillary occlusal
rim.
 The occlusal rims are inserted into the patients mouth.
 The patient is asked to close on the occlusal rims and
make protusive, retrusive, right and left lateral
movements of the mandible.

18. Recording the mandibular
movements

20.  Marking on the mandibular occlusal rim.when all
the movements are made,a diamond shaped
marking pattern rather than a line is formed on the
mandibular occlusal rim.
 The posterior most point of this diamond pattern
indicates the centric jaw relation.

21. PATTERSON’S METHOD.
 In this occlusal rim are made up of modelling wax.
 A trench or trough is made along the length of the mandibular
occlusal rim.
 A I:1 mixture of carborundum and dental plaster is loaded into the
trench.
 The occlusal rims are inserted and the patient is asked to perform
mandibular movements.
 These movements will produce compensating curves.
 The patient is asked to continue these movements till a
predetermined vertical dimension is obtained.
 Finally the patient is asked to retrude his jaw and occlusal rims are
fixed in this position with metal staples.

22. Trench made in the mandibular occlusal
rim

23. GRAPHIC METHODS.
 These methods are so called because they use graphs
or tracing to record the centric jaw relation.
 These are of two types:-
 1)Arrow point tracing.
 2)Pantograph.
 Arrow point tracing is a graphic record measured
across a single plane,whereas the pantograph is
measured three–dimensionally.

24. ARROW POINT TRACING
 It is a one-dimensional graphic tracing made using
gothic arch tracers.
 It is usually recorded in the horizontal plane.
 Arrow point tracers are used.
 A pen like pointer is attached to one occlusal rim and
a recording plate is placed on the other rim
 When the mandible moves the pointer draws
characterstic patterns on the recording plate. The
pointer is known as the CENTRAL BEARING POINT.
And the recording plate is known as CENTRAL
BEARING PLATE.

25.  They are so called as they act at the centre of the arch and
evenly distribute forces across the supporting structures.
 The pointer and the plate together are called as the
CENTRAL BEARING DEVICE.
 The characteristic pattern created on the recording plate is
called a CENTRAL ARROW POINT TRACING.
 It is defined as: The pattern obtained on the horizontal
plate used with a central bearing tracing device.”GPT

26.  ARROW point tracing is called so because the shape of
the tracing pattern resembles an arrow head.The apex
of the arrow point tracing gives the centric relation.
The apex of the arrow head should be sharp else the
tracing is incorrect.
 TYPES OF ARROW HEAD TRACERS:-
 1)Intra oral arrow head tracers.
 2)Extraoral arrow head tracers.

27. INTRA ORAL ARROW POINT TRACERS
 Central bearing device is located intra orally.
 Tracers are placed within the mouth.
 DISADVANTAGE-Tracers is not visible during the
procedure.
 PROCEDURE:-
 The record bases attached to the central bearing point
and the central bearing plate are inserted into the
patients mouth.
 The central bearing point is adjusted such that it
contacts the central bearing plate at a predetermined
vertical dimension.

28.  When the patient closes his mouth,the central bearing
point contacts the metal plate.
 The patient is asked to make anteroposterior and
lateral movements. While making these
movements,the central bearing point will draw the
tracing pattern on the central bearing plate.
 After completing the movements,the tracing is
removed and examined.The tracing should resemble
an arrow point with a sharp apex.if the apex is
blunt,the record is discarded and the procedure is
freshly repeated.

29. EXTRAORAL ARROW POINT TRACERS.
 The concept is similar to an intra–oral tracer. These
tracers have the same central bearing device attached
to the occlusal rims.
 Additionally, they have attachments that project
outside the mouth.An extraoral tracing pointer and
the recording plates are attached to projections.
 Since the recording pointer and the plates are situated
extraorally,the tracing can be examined as it is made.

30.  The size of the tracing pattern is also large. Hence, the
apex can be identified easily.

31. PANTOGRAPHIC TRACING.
 It is defined as :
 “A graphic record of the mandibular movement in
three planes as registered by the styli on the recording
tables of a pantograph; tracings of mandibular
movement recorded on plates in the horizontal and
saggital planes.” GPT.
 It is three-dimensional graphic tracer.
 Most accurate method.
 Even eccentric jaw relation can be recorded using
these instruments.

32. Pantographic tracer
 It is defined as,”An instrument used to graphically one
or more planes path of the mandibular movement and
to provide information for the programming of the
articulator.-GPT
 It resembles a complicated face-bow.the surface over
which the tracing is done is called a FLAG.
 A stylus (tracing pointer) is present for each flag.
 The styli draw tracing patterns on the flag.

34.  A pantographic tracer has six flags:-
 Two flags located perpendicular to one another
near the condyles.
 Totally there are four flags adjacent to the right and
left condylar guidances. They locate the
actual(true) hinge axis.
 Two flags are placed in the anterior region. They
record the anteroposterior movements.

35. REFERNCES.
 Prosthodontic treatment for edentulous patients-
Carl O Boucher.(12th edition)
 Textbook of prosthodontics-
Deepak Nallaswamy.
Essential of complete denture prosthodontics-Winkler
NET SOURCES
 www.wikipedia.com