Horizontal jaw relationsHorizontal jaw relations

Phillip pfaff (1756)Phillip pfaff (1756) Called “mush” or Called “mush” or

“ “Biscuit” or ”Squash Biscuit” or ”Squash bite”bite”

Classification of Horizontal jaw Classification of Horizontal jaw relationsrelations

A.A. Centric relationCentric relation

B.B. Eccentric relationEccentric relation a) protrusive relationsa) protrusive relations b) lateral relationsb) lateral relations > left lateral relations> left lateral relations > right lateral relations> right lateral relations

CENTRIC RELATIONCENTRIC RELATION

Maxillomandibular relationship.Maxillomandibular relationship. Condyles articulate with thinnest Condyles articulate with thinnest

avascular portion of their respective avascular portion of their respective disks.disks.

Condyle – disk assembly in its most Condyle – disk assembly in its most anterior superior position against the anterior superior position against the slopes of articular eminences.slopes of articular eminences.

Independent of tooth contacts.Independent of tooth contacts.

SIGNIFICANCE OF CENTRIC SIGNIFICANCE OF CENTRIC RELATION(CR)RELATION(CR)

CR is more definitive & independent of tooth presence or CR is more definitive & independent of tooth presence or absence.absence.

Recordable & reproducible over a period of time .Recordable & reproducible over a period of time . Serve as reference to established an occlusion.Serve as reference to established an occlusion. when CR & CO do not coincide, periodontium of natural when CR & CO do not coincide, periodontium of natural

teeth are endangered & instability of CDs.teeth are endangered & instability of CDs. Helps to detect mounting errors.Helps to detect mounting errors. Accurate CR record properly orient the lower cast to Accurate CR record properly orient the lower cast to

opening axis of articulator & the mandible.opening axis of articulator & the mandible. Helps in proper adjustment of condylar guidance for the Helps in proper adjustment of condylar guidance for the

control of eccentric movements of the instrument.control of eccentric movements of the instrument.

rim.rim.

Methods used to record centric Methods used to record centric relationrelation

A.A. Tactile / interocclusal check record.Tactile / interocclusal check record.B.B. functional / chew-in methods.functional / chew-in methods. a) Needle house method.a) Needle house method. b) Patterson’s method.b) Patterson’s method. c) Mayer’s methodc) Mayer’s method

cc. Graphic methods.. Graphic methods.

a) Intraoral tracings a) Intraoral tracings b) Extra oral tracingsb) Extra oral tracingsD. Terminal Hinge Axis Method.D. Terminal Hinge Axis Method.

Methods used to record centric Methods used to record centric relationrelation

E. Other Methods.E. Other Methods. a) Heating one of the surface of a) Heating one of the surface of

occlusal rim. occlusal rim. b) Deep heating or pooling b) Deep heating or pooling

method.method. c) soft wax / Celluloloid strip is c) soft wax / Celluloloid strip is

placed over lower rim.placed over lower rim. d) Soft wax cones are placed d) Soft wax cones are placed

over lower rim.over lower rim.

Tactile / interocclusal check record.Tactile / interocclusal check record.

Can be used to:Can be used to:

1) record CR1) record CR

2) verify CR on articulators2) verify CR on articulators

3) record eccentric 3) record eccentric

relations relations

Steps In Recording The tactile / Steps In Recording The tactile / Interocclusal Check RecordInterocclusal Check Record

Step # 01: Step # 01: Training the patientTraining the patient

Step # 02: Step # 02: Indexing The RimIndexing The Rim

Step # 03: Step # 03: Recording CRRecording CR

Bite Registration MaterialsBite Registration Materials

Quick setting plasterQuick setting plaster Bite registration (ZOE) pasteBite registration (ZOE) paste Bite registration waxBite registration wax Bite registration silicone Bite registration silicone

Requirements of bite Requirements of bite registration materialregistration material

Dimensionally accurate after setting.Dimensionally accurate after setting. Should be fluid in consistency during Should be fluid in consistency during

rerecording to avoid pressure .rerecording to avoid pressure . Adequate working timeAdequate working time Short setting timeShort setting time

Graphic/Excursive/ Gothic Arch Graphic/Excursive/ Gothic Arch Tracing Methods.Tracing Methods.

USESUSES1.1. To obtained the CR record records.To obtained the CR record records.

2.2. Used to verify CR records obtained Used to verify CR records obtained by other methods.by other methods.

3.3. Used to obtained protrusive & Used to obtained protrusive & lateral (eccentric) recordslateral (eccentric) records

Recording MethodRecording Method Central Bearing Device:Central Bearing Device:

1. Consist of pair of central bearing plates.2. The plate attached to maxillary rim contain stylus/

bearing pin.3. The plate attached to mandibular rim consist of tracing

table.4. The stylus traces an “ARROW POINT” corresponding to

mandibular movement.5. To obtained tracing, the tracing plate is painted with

some marking substance (carbon, ink, wax)6. Sharp apex of arrow point represents an accurate centric.

INTRA-ORAL TRACING METHODINTRA-ORAL TRACING METHOD

Take the tentative CR record & mount the Take the tentative CR record & mount the rims .rims .

Attaches the central bearing devices to Attaches the central bearing devices to corresponding rim.corresponding rim.

Adjust the stylus to obtained its contact to Adjust the stylus to obtained its contact to tracing plate at predetermined OVD.tracing plate at predetermined OVD.

Transfer the assembly into the mouth to Transfer the assembly into the mouth to obtained ‘arrow point’ tracing obtained ‘arrow point’ tracing corresponding to protrusive & lateral corresponding to protrusive & lateral movements.movements.

TRANSFERING THE RECORD TO TRANSFERING THE RECORD TO ARTICULATORARTICULATOR

Take 4×6 cm plastic strip ( bur box lid).Take 4×6 cm plastic strip ( bur box lid). Drill two hole middle of the strip, 4–to-6 mm gap Drill two hole middle of the strip, 4–to-6 mm gap

in between the holes.in between the holes. Fix the strip over the tracing plate in such a way Fix the strip over the tracing plate in such a way

that hole must corresponds to sharp apex of that hole must corresponds to sharp apex of arrow point while other hole must be over the line arrow point while other hole must be over the line representing protrusion or lateral movements.representing protrusion or lateral movements.

Shift the assembly into the mouth guide the Shift the assembly into the mouth guide the mandible into centric till stylus drops into the mandible into centric till stylus drops into the posterior hole.posterior hole.

Pour bite registering material b/w upper & lower Pour bite registering material b/w upper & lower wax rims , wait till it sets.wax rims , wait till it sets.

Remove & transfer the record to articulator.Remove & transfer the record to articulator.

DIFFICULTIES IN RECORDING DIFFICULTIES IN RECORDING THE CRTHE CR

BIOLOGICAL DIFFICULTIES;BIOLOGICAL DIFFICULTIES;1.1. NNeuromuscular in-coordination.2. TMJ problems.3. Bite of convenience.4. The amount & character of saliva.5.5. Maxillo-mandibular relationshipMaxillo-mandibular relationship

ANATOMICAL FACTORS;1. Resiliency of supporting tissues.2. Size & position of the tongue.3. The character & size of residual alveolar ridge

DIFFICULTIES IN RECORDING DIFFICULTIES IN RECORDING THE CRTHE CR

Mechanical Factors;Mechanical Factors;1.1. Stability of denture bases.Stability of denture bases.2.2. Character of pressure applied in recording the Character of pressure applied in recording the

CR.CR.3.3. Technique used in making the CR records.Technique used in making the CR records.4.4. Posture of the patient.Posture of the patient.

PSYCHOLOGICAL FACTOR;PSYCHOLOGICAL FACTOR;1.1. AnxietyAnxiety2.2. FatigueFatigue3.3. Frustration Frustration 4.4. Lake of cooperationLake of cooperation

ECCENTRIC RELATIONSECCENTRIC RELATIONS

“ “ANY HORIZONTAL RELATIONSHIP OF ANY HORIZONTAL RELATIONSHIP OF MANDIBLE TO MAXILLA OTHER THAN MANDIBLE TO MAXILLA OTHER THAN CENTRIC POSITION”CENTRIC POSITION”

IMPORTANCE OF ECCENTRIC IMPORTANCE OF ECCENTRIC RELATIONSRELATIONS

ECCENTRIC RELATION RECORDS ARE USED TO ECCENTRIC RELATION RECORDS ARE USED TO PROGRAM AN ADJUSTABLE ARTICULATOR TO PROGRAM AN ADJUSTABLE ARTICULATOR TO SIMULATE THE JAW MOVEMENTS.SIMULATE THE JAW MOVEMENTS.

PROGRAMMING OF ARTICULATOR HELPS TO PROGRAMMING OF ARTICULATOR HELPS TO ESTABLISHED BALANCED OCCLUSION IN A ESTABLISHED BALANCED OCCLUSION IN A REMOVABLE PROSTHESISIS.REMOVABLE PROSTHESISIS.

HELPS TO ESTABLISHED AN OCCLUSION WHICH IS HELPS TO ESTABLISHED AN OCCLUSION WHICH IS IN HARMONY WITH THE FUNCTIONAL IN HARMONY WITH THE FUNCTIONAL MOVEMENTS OF THE MANDIBLE.MOVEMENTS OF THE MANDIBLE.

IMPORTANANT ECCENTRIC IMPORTANANT ECCENTRIC RELATIONSRELATIONS

a) protrusive relationsa) protrusive relations

b) lateral relationsb) lateral relations > left lateral relations> left lateral relations > right lateral relations> right lateral relations

Protrusive RelationsProtrusive Relations

THE PROTRUDED JAW RELATION IS THAT WHERE THE PROTRUDED JAW RELATION IS THAT WHERE MANDIBLE CAN BE PROTRUDED TO A POSITION MANDIBLE CAN BE PROTRUDED TO A POSITION ANTERIOR TO THAT OF CR.ANTERIOR TO THAT OF CR.

PROTRUSIVE JAW RECORDS HELPS TO PROGRAM PROTRUSIVE JAW RECORDS HELPS TO PROGRAM HORIZONTAL CONDYLAR GUIDANCE.HORIZONTAL CONDYLAR GUIDANCE.

ALSO HELPS TO PROGROM LATERAL CONDYLAR ALSO HELPS TO PROGROM LATERAL CONDYLAR GUIDANCE.GUIDANCE.

““CHRISTENSENCHRISTENSEN’’S PHENOMENON”S PHENOMENON”

METHODS TO OBTAINED METHODS TO OBTAINED PROTRUSIVE RECORDSPROTRUSIVE RECORDS

A. Tactile / interocclusal check record.A. Tactile / interocclusal check record.

B. functional / chew-in methods.B. functional / chew-in methods. a) Needle house method.a) Needle house method. b) Patterson’s method.b) Patterson’s method. c) Mayer’s methodc) Mayer’s method

cc. Graphic methods.. Graphic methods. a) Intraoral tracings a) Intraoral tracings b) Extra oral tracingsb) Extra oral tracings

Lateral jaw relationsLateral jaw relations The relation of mandible to maxilla when it is The relation of mandible to maxilla when it is

moving to left or right of CR .moving to left or right of CR .

Site to which the the mandible is moving is called Site to which the the mandible is moving is called ‘WORKING SITE’, representing characteristic ‘WORKING SITE’, representing characteristic ““BENNETT SHIFT”.BENNETT SHIFT”.

Site from where mandible is moving is called Site from where mandible is moving is called ‘BALANCING SITE’, representing characteristic ‘BALANCING SITE’, representing characteristic ““BENNETT MOVEMENT”.BENNETT MOVEMENT”.

Used to program the ‘lateral condylar guidance’.Used to program the ‘lateral condylar guidance’. Hanau semi-adjustable articulators do not accept Hanau semi-adjustable articulators do not accept

lateral relation records.lateral relation records.

METHODS USED TO RECORD METHODS USED TO RECORD LATERAL JAW RELATIONS LATERAL JAW RELATIONS

1.1. Lateral check recordsLateral check records2.2. Graphic methodGraphic method3.3. Hanau’s formula (1930)Hanau’s formula (1930)

L = H/8 +12L = H/8 +12Where Where LL= lateral condylar inclination= lateral condylar inclination HH= Horizontal condylar inclination= Horizontal condylar inclination