Edentulous Jaw relations/ online orthodontic courses

ESTABLISHINGESTABLISHING
EDENTULOUS JAWEDENTULOUS JAW
RELATIONSHIPSRELATIONSHIPS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

INTRODUCTIONINTRODUCTION
The recording of jaw relations in the treatmentThe recording of jaw relations in the treatment
of edentulous patients aims at facilitating theof edentulous patients aims at facilitating the
adaptation of the complete dentures to theadaptation of the complete dentures to the
masticatory system to give them an optimalmasticatory system to give them an optimal
& comfortable function.& comfortable function.

TO ACHIEVE THIS GOAL…..TO ACHIEVE THIS GOAL…..
 The recording must include an appropriate VDThe recording must include an appropriate VD
of occlusion.of occlusion.
 Stable occlusal contacts in harmony with theStable occlusal contacts in harmony with the
existing TMJ & masticatory muscle functions.existing TMJ & masticatory muscle functions.
 The relationship between the prosthesis & oro-The relationship between the prosthesis & oro-
facial soft tissues and musculature.facial soft tissues and musculature.

CUSTOMISING THE OCCLUSALCUSTOMISING THE OCCLUSAL
RIMSRIMS
 LABIAL FULLNESS:LABIAL FULLNESS:
Facial esthetics as a guideFacial esthetics as a guide
Phonetics as a guidePhonetics as a guide
 INCISAL VISIBILITY:INCISAL VISIBILITY:
Generally the amount of tooth displayed at restGenerally the amount of tooth displayed at rest
varies with age.varies with age.
 FLAT OCCLUSAL PLANE:FLAT OCCLUSAL PLANE:
 Shunting effect must be preventedShunting effect must be prevented

JAW RELATIONSJAW RELATIONS
 ““Any relation of the mandible to the maxilla”Any relation of the mandible to the maxilla”
 The three types are :The three types are :
orientation jaw relationorientation jaw relation
vertical jaw relationvertical jaw relation
horizontal jaw relationhorizontal jaw relation

VERTICAL JAW RELATIONVERTICAL JAW RELATION
““The length of the face as determined by theThe length of the face as determined by the
amount of separation of the jaws”.amount of separation of the jaws”.
VDr = length of the face when the mandible isVDr = length of the face when the mandible is
in its rest position.in its rest position.
VDo = length of the face when the teeth are inVDo = length of the face when the teeth are in
contact & the mandible is in CR.contact & the mandible is in CR.
VDR=VDO+FREE WAY SPACEVDR=VDO+FREE WAY SPACEwww.indiandentalacademy.com

METHODS OF RECORDINGMETHODS OF RECORDING
VERTICAL JAW RELATIONVERTICAL JAW RELATION

METHODS OF RECORDING VDRMETHODS OF RECORDING VDR
Facial measurements after swallowing &Facial measurements after swallowing &
relaxing.relaxing.
Tactile sensationTactile sensation
Anatomical landmarksAnatomical landmarks
SpeechSpeech
Facial expressionFacial expression

FACIAL MEASUREMENTS AFTERFACIAL MEASUREMENTS AFTER
SWALLOWING & RELAXINGSWALLOWING & RELAXING
 Given by SHANAHANGiven by SHANAHAN
Patient is asked to sit upright & relax hisPatient is asked to sit upright & relax his
shouldersshoulders
Reference points are markedReference points are marked
Functional movements are madeFunctional movements are made
As the movements are done his mandibleAs the movements are done his mandible
comes to its physiological rest position & thecomes to its physiological rest position & the
distance between the points are markeddistance between the points are marked

TACTILE SENSATIONTACTILE SENSATION
 Given by LYTLEGiven by LYTLE
Pt. is asked to open his mouth wide till hePt. is asked to open his mouth wide till he
feels discomfortfeels discomfort
And close slowly & stop closing when he feelsAnd close slowly & stop closing when he feels
that his muscles are relaxed and comfortablethat his muscles are relaxed and comfortable
The distance between 2 reference points isThe distance between 2 reference points is
recorded & compared with the swallowingrecorded & compared with the swallowing
methodmethod

ANATOMIC LANDMARKSANATOMIC LANDMARKS
 Given by WILLISGiven by WILLIS
The distance between the pupil of the eye &The distance between the pupil of the eye &
the rima oris & the distance between anteriorthe rima oris & the distance between anterior
nasal spine and the lower border of mandiblenasal spine and the lower border of mandible
is measured using Willis guideis measured using Willis guide
If both the distances are equal, the jaws areIf both the distances are equal, the jaws are
considered at restconsidered at rest

SPEECHSPEECH
 Ask the pt. to repeatedly pronounce the letterAsk the pt. to repeatedly pronounce the letter
“M”“M”
 Measure the distance between the referenceMeasure the distance between the reference
points after a conversationpoints after a conversation

FACIAL EXPRESSIONFACIAL EXPRESSION
 Skin around the eyes & chin should be relaxedSkin around the eyes & chin should be relaxed
 The lips should have a slight contact in a singleThe lips should have a slight contact in a single
planeplane
 The nostrils are relaxedThe nostrils are relaxed

METHODS OF RECORDING VDOMETHODS OF RECORDING VDO
 MECHANICALMECHANICAL
METHODS :METHODS :
Ridge relationsRidge relations
Pre-extraction recordsPre-extraction records
 PHYSIOLOGICALPHYSIOLOGICAL
METHODS :METHODS :
Physiological restPhysiological rest
positionposition
PhoneticsPhonetics
F,V,S-speaking ant.toothF,V,S-speaking ant.tooth
relationsrelations
Swallowing thresholdSwallowing threshold

Contd…Contd…
Tactile sensationTactile sensation
Patient reportedPatient reported
perception of comfortperception of comfort
Boos bimeterBoos bimeter
Parks theory ofParks theory of
determining VDdetermining VD

RIDGE RELATIONRIDGE RELATION
Distance from the incisive papilla to theDistance from the incisive papilla to the
mandibular incisorsmandibular incisors

CONTD……CONTD……
Parallelism of the ridges – SEARS theoryParallelism of the ridges – SEARS theory

PRE EXTRACTION RECORDSPRE EXTRACTION RECORDS

PROFILE RADIOGRAPHSPROFILE RADIOGRAPHS
 They were used initially, but because of radiationThey were used initially, but because of radiation
risks they cannot be considered adequate todayrisks they cannot be considered adequate today
for routine clinical practice.for routine clinical practice.

CASTS OF TEETH IN OCCLUSIONCASTS OF TEETH IN OCCLUSION
 It is a simple method of recordingIt is a simple method of recording
 The size & shape of the teeth can be notedThe size & shape of the teeth can be noted
 It gives an indication of the amount of spaceIt gives an indication of the amount of space
required between the ridges for the teeth of thisrequired between the ridges for the teeth of this
sizesize

PROFILE PHOTOGRAPHSPROFILE PHOTOGRAPHS
 Given by WRIGHTGiven by WRIGHT
These are made before extraction & taken inThese are made before extraction & taken in
maximum occlusionmaximum occlusion
 Wright’s formulaWright’s formula
Inter pupillary distance : brow-chin distance ofInter pupillary distance : brow-chin distance of
pt. & photopt. & photo pt. & photopt. & photo

PROFILE SILHOUETTESPROFILE SILHOUETTES
 An accurate silhouette is made with cardboardAn accurate silhouette is made with cardboard
 It can be used as a templateIt can be used as a template
 As it is taken from pre extraction photographAs it is taken from pre extraction photograph
which shows the VD at restwhich shows the VD at rest
 When positioned on patient’s face whileWhen positioned on patient’s face while
recording the VD at occlusion, the chin shouldrecording the VD at occlusion, the chin should
be atleast 2mm above the level of the lowerbe atleast 2mm above the level of the lower
border of the silhouetteborder of the silhouette
 Lead wires can also be usedLead wires can also be used

MEASUREMENT FROM FORMERMEASUREMENT FROM FORMER
DENTURESDENTURES
 Pts. existing denture is a valuable pre extractionPts. existing denture is a valuable pre extraction
recordrecord
 A BOOLEYS GAUGE is used to measure theA BOOLEYS GAUGE is used to measure the
distance between the border of the maxillary &distance between the border of the maxillary &
the mandibular denture when both thesethe mandibular denture when both these
dentures are in occlusiondentures are in occlusion

FACIAL MEASUREMENTSFACIAL MEASUREMENTS
 Facial measurements can be measured by theFacial measurements can be measured by the
following :following :
DakometerDakometer
Willis gaugeWillis gauge
Sorensons profile guideSorensons profile guide
Swensons methodSwensons method

DAKOMETERDAKOMETER
 The instrument is positioned on the bridge ofThe instrument is positioned on the bridge of
the nose with compound.the nose with compound.
 The chin piece is screwed till it touches the frontThe chin piece is screwed till it touches the front
of the chin.of the chin.
 A spring pressure gauge controls the pressure.A spring pressure gauge controls the pressure.
 An incisor attachment records position of theAn incisor attachment records position of the
central incisors.central incisors.
 Records are noted & the compound nose pieceRecords are noted & the compound nose piece
is preserved for reassembly after extraction.is preserved for reassembly after extraction.

WILLIS GAUGEWILLIS GAUGE

SWENSONS METHODSWENSONS METHOD
 An ACRYLIC FACE MASK is made beforeAn ACRYLIC FACE MASK is made before
extraction using a facial impression and a cast.extraction using a facial impression and a cast.
 This method is not practical.This method is not practical.

PHYSIOLOGICAL METHODSPHYSIOLOGICAL METHODS
 Physiological rest positionPhysiological rest position
 PhoneticsPhonetics
 F,V,S speaking anterior tooth relationF,V,S speaking anterior tooth relation
 Swallowing thresholdSwallowing threshold
 Tactile senseTactile sense
 Pt. reported perception of comfortPt. reported perception of comfort
 Boos bimeterBoos bimeter

PHYSIOLOGICAL REST POSITIONPHYSIOLOGICAL REST POSITION
 Given by NISWONGER (1934)Given by NISWONGER (1934)
THOMPSON (1946)THOMPSON (1946)
The pt. is asked to sit upright with his headThe pt. is asked to sit upright with his head
unsupportedunsupported
Upper & lower occlusal rims are inserted &Upper & lower occlusal rims are inserted &
the pt. is asked to swallow and relaxthe pt. is asked to swallow and relax
When the relaxation is obvious there will beWhen the relaxation is obvious there will be
space present between the rimsspace present between the rims
Its called as FREEWAY SPACEIts called as FREEWAY SPACE

CONTD…..CONTD…..
 It is about 2-4 mmIt is about 2-4 mm
 VD at rest =VD at occlusion + freeway spaceVD at rest =VD at occlusion + freeway space
 If the freeway space is > 4mm, then the VD atIf the freeway space is > 4mm, then the VD at
occlusion is considered to be smallocclusion is considered to be small
 If the freeway space is < 2mm, then the VD atIf the freeway space is < 2mm, then the VD at
occlusion may be too greatocclusion may be too great

PHONETICSPHONETICS
SILVERMANS CLOSEST SPEAKINGSILVERMANS CLOSEST SPEAKING
SPACESPACE
It measures the VD when the mandible is in functionIt measures the VD when the mandible is in function
When sounds like ‘ch’, ‘s’, ‘j’ are pronounced, theWhen sounds like ‘ch’, ‘s’, ‘j’ are pronounced, the
upper & lower teeth reach their closest relationshipupper & lower teeth reach their closest relationship
without contactwithout contact
The minimal amount of space between the teeth inThe minimal amount of space between the teeth in
this position is called the Silvermans closestthis position is called the Silvermans closest
speaking spacespeaking space

ITS NOT THE FREEWAY SPACEITS NOT THE FREEWAY SPACE
CLOSEST SPEAKINGCLOSEST SPEAKING
SPACESPACE
 Suggested by SilvermanSuggested by Silverman
 It is dynamic &It is dynamic &
functionalfunctional
 Values are :Values are :
Normal : 1.5-3.0 mmNormal : 1.5-3.0 mm
Class II : 3.0- 6.0 mmClass II : 3.0- 6.0 mm
Class III: 0.5- 1.0 mmClass III: 0.5- 1.0 mm
FREE WAY SPACEFREE WAY SPACE
 Proposed by NiswongerProposed by Niswonger
& Thompson& Thompson
 It is staticIt is static
 Values are :Values are :
Class I : 2.0-4.0 mmClass I : 2.0-4.0 mm
Class II: > 4.0 mmClass II: > 4.0 mm
Class III: 1.0 mmClass III: 1.0 mm

THE “F”, “V”, “S” SPEAKINGTHE “F”, “V”, “S” SPEAKING
ANTERIOR TOOTH RELATIONANTERIOR TOOTH RELATION
 Given by POUND & MURRELGiven by POUND & MURREL
 The position of the anterior teeth is determinedThe position of the anterior teeth is determined
by the position of the maxillae when the pt.by the position of the maxillae when the pt.
pronounces words beginning with “F” or “V”pronounces words beginning with “F” or “V”
 The position of the lower anterior teeth isThe position of the lower anterior teeth is
determined by the position of the mandibledetermined by the position of the mandible
when the pt. pronounces words beginning withwhen the pt. pronounces words beginning with
the letter “S”the letter “S”

 When the “F” & “V” sounds are articulated, theWhen the “F” & “V” sounds are articulated, the
incisal edges of the maxillary anterior teethincisal edges of the maxillary anterior teeth
create a seal on the moist area of the vermilioncreate a seal on the moist area of the vermilion
border of the lower lipborder of the lower lip
 Have the pt. repeat the word “first” or “victor”Have the pt. repeat the word “first” or “victor”
 When the “S” sounds are articulated, theWhen the “S” sounds are articulated, the
mandible moves forward. The incisal edges ofmandible moves forward. The incisal edges of
the anterior teeth do not contactthe anterior teeth do not contact

PATIENT REPORTEDPATIENT REPORTED
PERCEPTION OF COMFORTPERCEPTION OF COMFORT
 Simple methodSimple method
 Here, record bases with excessively tall occlusalHere, record bases with excessively tall occlusal
rims are inserted into the pts. mouthrims are inserted into the pts. mouth
 The excess base plate wax is removed stepwiseThe excess base plate wax is removed stepwise
till the pt. perceives that occlusal height astill the pt. perceives that occlusal height as
comfortablecomfortable

BOOS BIMETERBOOS BIMETER
 Given by RALPH BOOS – 1940Given by RALPH BOOS – 1940
The maximum biting force occurs at theThe maximum biting force occurs at the
occlusal VDocclusal VD
A device that measures the biting forceA device that measures the biting force
(bimeter) is attached to the mandibular record(bimeter) is attached to the mandibular record
base & a metal plate (central bearing point) tobase & a metal plate (central bearing point) to
the maxillarythe maxillary
A screw is turned to adjust the verticalA screw is turned to adjust the vertical
relationrelation

 The record bases are inserted into the pts.The record bases are inserted into the pts.
mouth & the pt. is asked to bite on the recordmouth & the pt. is asked to bite on the record
bases at different degrees of jaw separationbases at different degrees of jaw separation
 The pressure reading on the bimeter is noted.The pressure reading on the bimeter is noted.
The highest value is called the “Power point”The highest value is called the “Power point”
 The bimeter is observed when the power pointThe bimeter is observed when the power point
is reachedis reached

FACTORS AFFECTING RESTFACTORS AFFECTING REST
POSITIONPOSITION
 Head positionHead position
 TimeTime
 Neuromuscular disturbancesNeuromuscular disturbances
 Position in spacePosition in space

CLINICAL SIGNIFICANCE OF VDCLINICAL SIGNIFICANCE OF VD
 The vertical jaw relation is the most criticalThe vertical jaw relation is the most critical
record b’coz errors in this record produce therecord b’coz errors in this record produce the
first signs of discomfort.first signs of discomfort.
 It can affectIt can affect
Facial profileFacial profile
Physico-functional stability of denturePhysico-functional stability of denture
Speech disturbanceSpeech disturbance
Neuromuscular disturbancesNeuromuscular disturbances

EFFECTS OF ↑ VDEFFECTS OF ↑ VD
 ↑↑ Trauma to the denture bearing areaTrauma to the denture bearing area
 ↑↑ Lower facial heightLower facial height
 Difficulty in swallowing & speechDifficulty in swallowing & speech
 Pain & clicking in the TMJPain & clicking in the TMJ
 Clicking of teethClicking of teeth
 Stretching of facial muscles, leading to aStretching of facial muscles, leading to a
stretched appearance of the face.stretched appearance of the face.

EFFECTS OF ↓ VDEFFECTS OF ↓ VD
 ↓↓ Lower facial heightLower facial height
 Angular cheilitis due to folding of the corner ofAngular cheilitis due to folding of the corner of
mouthmouth
 Cheek bitingCheek biting
 Pain, clicking & discomfort to the TMJPain, clicking & discomfort to the TMJ
 Loss of lip fullnessLoss of lip fullness
 Obstruction of the opening of the eustachianObstruction of the opening of the eustachian
tube due to the elevation of the soft palate duetube due to the elevation of the soft palate due
to elevation of the tongue.to elevation of the tongue.

CENTRIC RELATIONCENTRIC RELATION
"The maxillo mandibular relationship in which the"The maxillo mandibular relationship in which the
condyles articulate with the thinnest avascularcondyles articulate with the thinnest avascular
portion of their respective discs with theportion of their respective discs with the
complex in the antero-superior position againstcomplex in the antero-superior position against
the slopes of the articular eminences. Thisthe slopes of the articular eminences. This
position is independent of tooth contact. Thisposition is independent of tooth contact. This
position is clinically discernible when theposition is clinically discernible when the
mandible is directed superior and anteriorly. It ismandible is directed superior and anteriorly. It is
restricted to a purely rotary movement about therestricted to a purely rotary movement about the
transverse horizontal axis."transverse horizontal axis."

CONTROVERSIES REGARDINGCONTROVERSIES REGARDING
 McCollum 1920McCollum 1920  rear most condylar positionrear most condylar position
 Granger 1962Granger 1962  up most, rear most positionup most, rear most position
 Stuart 1969Stuart 1969  RUM positionRUM position
 Celenza 1978Celenza 1978  condyle disc assemblycondyle disc assembly
braced superiorly &braced superiorly &
anteriorly against theanteriorly against the
posterior slope of theposterior slope of the
eminentiaeminentia
 KEYWORD : The discrepancy between the RUMKEYWORD : The discrepancy between the RUM
position & antero superior position in the condylarposition & antero superior position in the condylar
region is 0.2 mm.region is 0.2 mm.

HOW TO UNDERSTAND CRHOW TO UNDERSTAND CR
WITHOUT GETTING CONFUSEDWITHOUT GETTING CONFUSED
WITH THE CONTROVERSIES INWITH THE CONTROVERSIES IN
ITS DEFINITION???ITS DEFINITION???

FUNCTIONAL VsFUNCTIONAL Vs
MORPHOLOGICAL DEFINITIONMORPHOLOGICAL DEFINITION
 Centric is best understood if we define it as “when it isCentric is best understood if we define it as “when it is
required to select one mandibular to maxilla/condyle –required to select one mandibular to maxilla/condyle –
fossa relationship that is most conducive to comfort ,fossa relationship that is most conducive to comfort ,
function & health of the odontostomatognathic system,function & health of the odontostomatognathic system,
without any controversy it would be CR position”.without any controversy it would be CR position”.
 It is a FUNCTIONAL definition, while GPT definitionIt is a FUNCTIONAL definition, while GPT definition
is a MORPHOLOGICAL definition.is a MORPHOLOGICAL definition.
 The functional defn. tells us why centric is necessary &The functional defn. tells us why centric is necessary &
the morphological defn. helps us in securing thethe morphological defn. helps us in securing the
functional position.functional position.

METHODS OF RETRUDING THEMETHODS OF RETRUDING THE
MANDIBLEMANDIBLE
 The methods include :The methods include :
Chin point guidance – GuichetChin point guidance – Guichet
Bimanual method –Peter DawsonBimanual method –Peter Dawson
Three finger method –Peter thomasThree finger method –Peter thomas
Anterior deprogrammer –LongWilliamsonAnterior deprogrammer –LongWilliamson

DIFFICULTIES IN RETRUDINGDIFFICULTIES IN RETRUDING
THE MANDIBLETHE MANDIBLE
 Biological causes :Biological causes :
lack of co-ordination between groups oflack of co-ordination between groups of
opposing muscles.opposing muscles.
habitual eccentric jaw relationhabitual eccentric jaw relation
 Physiological causes :Physiological causes :
inability of the patients to follow the instructionsinability of the patients to follow the instructions
 Mechanical causes :Mechanical causes :
poorly fitting base platespoorly fitting base plates

METHODS OF RECORDINGMETHODS OF RECORDING
 Physiologic methodsPhysiologic methods
 Functional methodsFunctional methods
 Graphic methodsGraphic methods
 Radiographic methodsRadiographic methods
 Other methodsOther methods

PHYSIOLOGIC METHODPHYSIOLOGIC METHOD
 Tactile or Inter occlusal check recordTactile or Inter occlusal check record
 Pressure less methodPressure less method
 Pressure methodPressure method

TACTILE OR INTER-OCCLUSALTACTILE OR INTER-OCCLUSAL
CHECK RECORD METHODCHECK RECORD METHOD
 In this method , tentative CR is recordedIn this method , tentative CR is recorded
 The casts are articulated based on the tentativeThe casts are articulated based on the tentative
jaw relationjaw relation
 Teeth arrangement is done & an inter-occlusalTeeth arrangement is done & an inter-occlusal
registration is maderegistration is made
 The tentative jaw relation is verified with theThe tentative jaw relation is verified with the
inter-occlusal record & errors are correctedinter-occlusal record & errors are corrected

RATIONALE BEHIND BOTH THERATIONALE BEHIND BOTH THE
METHODSMETHODS
There are two schools of thought regardingThere are two schools of thought regarding
pressure used while recording CR :pressure used while recording CR :
 Minimal closing pressure :Minimal closing pressure :
tissues are not displacedtissues are not displaced
 Heavy closing pressure :Heavy closing pressure :
produce the same displacement of tissueproduce the same displacement of tissue
that occurs during masticationthat occurs during mastication

STATIC OR PRESSURELESSSTATIC OR PRESSURELESS
METHODMETHOD
 Its called as the “NICK & NOTCH” methodIts called as the “NICK & NOTCH” method

PRESSURE METHODPRESSURE METHOD
 After establishing the VD, the upper occlusalAfter establishing the VD, the upper occlusal
rim is inserted in the pts. mouthrim is inserted in the pts. mouth
 The lower rim is fabricated of excess height. TheThe lower rim is fabricated of excess height. The
entire lower rim is softened in a water bath &entire lower rim is softened in a water bath &
inserted into the pts. mouthinserted into the pts. mouth
 The pt. is guided to close in CRThe pt. is guided to close in CR
 After the pt. closes his mouth till theAfter the pt. closes his mouth till the
predetermined VD, both the rims are removed,predetermined VD, both the rims are removed,
cooled & articulatedcooled & articulated

FUNCTIONAL METHODSFUNCTIONAL METHODS
 Needle house methodNeedle house method
 Pattersons methodPattersons method
 Meyers methodMeyers method

NEEDLEHOUSE METHODNEEDLEHOUSE METHOD

PATTERSONS METHODPATTERSONS METHOD

GRAPHIC METHODSGRAPHIC METHODS
 Intra oral methodIntra oral method
 Extra oral methodExtra oral method

INTRA ORAL TRACINGINTRA ORAL TRACING
 The central bearing device is located intra orallyThe central bearing device is located intra orally
& is more simple compared to the extra oral& is more simple compared to the extra oral
arrow point tracingarrow point tracing
 The tracer is placed within the mouthThe tracer is placed within the mouth
 The tracer is not visible during the procedure &The tracer is not visible during the procedure &
the size of the tracing is very small making itthe size of the tracing is very small making it
difficult to determine the apex of the tracingdifficult to determine the apex of the tracing

EXTRA ORAL TRACINGEXTRA ORAL TRACING
 They are similar to the intra oral tracersThey are similar to the intra oral tracers
 Additionally, they have attachments that projectAdditionally, they have attachments that project
outside the mouthoutside the mouth
 The size of the tracing pattern is larger, &theThe size of the tracing pattern is larger, &the
apex can be identified easilyapex can be identified easily

OTHER METHODSOTHER METHODS
 Using strips of celluloidUsing strips of celluloid
 Deep heating or pooling methodDeep heating or pooling method
 PantographsPantographs

PANTOGRAPHSPANTOGRAPHS
 Consists of six styli & tracing tables attached toConsists of six styli & tracing tables attached to
the maxilla & mandible by means of a specialthe maxilla & mandible by means of a special
kinematic face bow & clutcheskinematic face bow & clutches
 Two tables are adjacent to each condyle & twoTwo tables are adjacent to each condyle & two
anteriorly on either side of the mouthanteriorly on either side of the mouth
 The tracings produced are called “Pantograms”The tracings produced are called “Pantograms”
 Pantograms are used to program on a fullyPantograms are used to program on a fully
adjustable articulatoradjustable articulator

SIGNIFICANCE OF CRSIGNIFICANCE OF CR
 It is a repeatable, reproducible & recordableIt is a repeatable, reproducible & recordable
positionposition
 It is a definite learned positionIt is a definite learned position
 It acts as a centre from which all movements canIt acts as a centre from which all movements can
be madebe made
 It is a definite entity , so it used as a referenceIt is a definite entity , so it used as a reference
point in establishing COpoint in establishing CO
 It is helpful in adjusting condylar guidance in anIt is helpful in adjusting condylar guidance in an
articulator to produce balanced occlusionarticulator to produce balanced occlusion

RELATION BETWEEN CR & CORELATION BETWEEN CR & CO
 CR & CO need not be the same in a dentulous patientCR & CO need not be the same in a dentulous patient
 Edentulous people who wear complete dentures areEdentulous people who wear complete dentures are
provided with CRO so that they can learn to pull theprovided with CRO so that they can learn to pull the
mandible back & close into a repeatable positionmandible back & close into a repeatable position
enabling the dentures to remain tightly securedenabling the dentures to remain tightly secured
 CRO is the simultaneous even contact between max. &CRO is the simultaneous even contact between max. &
mand. Teeth into maximum interdigitation with themand. Teeth into maximum interdigitation with the
mandible in CRmandible in CR

FACTORS INFLUCENCING THEFACTORS INFLUCENCING THE
CR RECORDSCR RECORDS
 The resiliency of the supporting tissuesThe resiliency of the supporting tissues
 The stability of the recording basesThe stability of the recording bases
 The TMJ & its associated NM mechanismsThe TMJ & its associated NM mechanisms
 The technique usedThe technique used
 The skill of the dentistThe skill of the dentist
 The health & co-operation of the patientThe health & co-operation of the patient
 The posture of the patientThe posture of the patient
 The size & position of the tongueThe size & position of the tongue

COMPLICATIONS IN RECORDINGCOMPLICATIONS IN RECORDING
CRCR
 Biological factors :Biological factors :
RealeffRealeff
TMJ’s structureTMJ’s structure
 Mechanical factors :Mechanical factors :
Cast mounting procedureCast mounting procedure
Denture processingDenture processing

ECCENTRIC JAW RELATIONECCENTRIC JAW RELATION
““Any relationship of the mandible to the maxillaAny relationship of the mandible to the maxilla
other than CR”.other than CR”.
 It includes :It includes :
Protrusive jaw relationProtrusive jaw relation
Lateral jaw relationLateral jaw relation

PROTRUSIVE JAW RELATIONPROTRUSIVE JAW RELATION
 When the mandible is protruded there is aWhen the mandible is protruded there is a
development of distal space between the upperdevelopment of distal space between the upper
& lower occlusal surfaces of the occlusal rims or& lower occlusal surfaces of the occlusal rims or
dentures. This is known as “Christensen’sdentures. This is known as “Christensen’s
phenomenon”.phenomenon”.
 It is caused by the downward & forwardIt is caused by the downward & forward
movement of the condyles.movement of the condyles.

LATERAL JAW RELATIONLATERAL JAW RELATION
 Lateral movements are complex activities inLateral movements are complex activities in
most humansmost humans
 They are of paramount importance because theyThey are of paramount importance because they
influence the inter cuspation of teeth in workinginfluence the inter cuspation of teeth in working
masticationmastication
 Bennett movement is the bodily wide shift ofBennett movement is the bodily wide shift of
the whole mandible that occurs in lateralthe whole mandible that occurs in lateral
movementsmovements
 L =( H/8 + 12)L =( H/8 + 12)

METHODS OF SEALING THEMETHODS OF SEALING THE
RECORD BLOCKSRECORD BLOCKS
 The record blocks can be fused together using aThe record blocks can be fused together using a
heated instrumentheated instrument
 ZOE impression paste can be usedZOE impression paste can be used
 Staple pins are also usedStaple pins are also used

ERRORS IN REGISTERING JAWERRORS IN REGISTERING JAW
RELATIONSRELATIONS
 Record bases that do not fit accuratelyRecord bases that do not fit accurately
 A shifting of the record bases over displaceableA shifting of the record bases over displaceable
tissues ( Realeff)tissues ( Realeff)
 Excessive pressure exerted by the patient duringExcessive pressure exerted by the patient during
the recordingthe recording
 Patient not registering CR because of systemicPatient not registering CR because of systemic
factorsfactors
 Interference of heels of the casts duringInterference of heels of the casts during
mountingmounting

CONCLUSIONCONCLUSION
 ““Establishing the jaw relation” is an importantEstablishing the jaw relation” is an important
step in fabrication of complete dentures.step in fabrication of complete dentures.
 There are many methods of obtaining jawThere are many methods of obtaining jaw
relations.relations.
 In the final analysis, it is the experience andIn the final analysis, it is the experience and
judgment of the operator which helps injudgment of the operator which helps in
determining what is right for the patient.determining what is right for the patient.

BIBLIOGRAPHYBIBLIOGRAPHY
1.1. Prosthodontic treatment for edentulous pts-Prosthodontic treatment for edentulous pts-
Zarb BolenderZarb Bolender
2.2. Essentials of complete dentureEssentials of complete denture
prosthodontics-Sheldon Winklerprosthodontics-Sheldon Winkler
3.3. Clinical dental prosthetics-H.R.B.FennClinical dental prosthetics-H.R.B.Fenn
4.4. Syllabus of complete dentures- Charles M.Syllabus of complete dentures- Charles M.
HeartwellHeartwell
5.5. Fabrication of complete dentures- SwensonFabrication of complete dentures- Swenson

CONTD…CONTD…
66 Impressions for complete dentures- Bernaud LevinImpressions for complete dentures- Bernaud Levin
77 Pre-extraction records for CD fabricationPre-extraction records for CD fabrication
JPD2004;91:55-8JPD2004;91:55-8
88 Physiologic jaw relation and occlusion of CDPhysiologic jaw relation and occlusion of CD
JPD2004;91:203-5JPD2004;91:203-5
99 Factors influencing CR records in edentulous mouthsFactors influencing CR records in edentulous mouths
JPD2005;93:305-10JPD2005;93:305-10
1010 The Glossary of Prosthodontic Terms-8 JPD2005;94The Glossary of Prosthodontic Terms-8 JPD2005;94

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