Methods of determining vertical

dimension of occlusion

1) Pre-extraction records

a) Willis gauge

This device could used to

measure V D O before measure V D O before

teeth extraction and

then recorded in the

patient record.

b) Profile tracing:

done using lead wire adapted to the patient profile before extraction

c) Face mask

clear acrylic resin mask could be made before extraction.

d) Articulated casts

– Allow determining vertical dimension

– Indicate the amount of vertical and horizontal overlap

e) Profile photograph

taken before teeth extractions. The distance between two fixed points is measured and then multiplied by factor.multiplied by factor.

f) Radiograph

patient’s lateral cephalometric radiograph may be helpful.

2) Measurements of the former denture

the vertical dimension of occlusion

could be measure from previous dentures

this measured could be correlated with

the patient’s face observations.the patient’s face observations.

3) Power Point

The use of power device (Boos Bimeter) to determine the vertical separation of the jaws at the maximum masticatory force.

4) phonetics “Closest-speaking space”

it is the relationship of the occlusal surfaces and incisal edges of the mandibular teeth to the maxillary teeth during function and rapid speech.

this is done by asking the patient to repeat words started with letter “S” and evaluate space between occlusal rims

5) Ridge Relationship

it is suggested that parallelism of both

arches is an indication of the correct

vertical height.

Parallel ridges Divergent ridges

� clicking of the teeth

� facial distortion, tense strained appearance

� difficulty closing lips

� difficulty swallowing

� soreness and discomfort under the denture

INADEQUATE INTEROCCLUSALINADEQUATE INTEROCCLUSAL

REST SPACE RESULTS IN;REST SPACE RESULTS IN;

� soreness and discomfort under the denture

� increased ridge resorption due to trauma

Inadequate InterocclusalInadequate Interocclusal RestRest Space = Excessive VDOSpace = Excessive VDO

�� reduced interarch distancereduced interarch distance when the teeth are in when the teeth are in occlusionocclusion

�� overclosure is overclosure is potentially damaging to the TMJpotentially damaging to the TMJ

�� normal normal tongue space is limitedtongue space is limited

�� facial distortionfacial distortion, , chin is closer to nose, commissure of the lips chin is closer to nose, commissure of the lips

turns down , lips loose their fullnessturns down , lips loose their fullness

�� musclesmuscles of facial expression of facial expression loose their tonicityloose their tonicity,,

�� face appears flabbyface appears flabby

EXCESSIVE INTEROCCLUSAL REST SPACE RESULTS IN;EXCESSIVE INTEROCCLUSAL REST SPACE RESULTS IN;

�� face appears flabbyface appears flabby

�� angular cheilitisangular cheilitis is sometimes attributed is sometimes attributed

to overclosureto overclosure

Excessive Interocclusal Rest Space= Inadequate VDOExcessive Interocclusal Rest Space= Inadequate VDO

�� ””s” soundss” sounds

�� count from count from 6060--7070

CLOSEST SPEAKING SPACECLOSEST SPEAKING SPACE

�� Measures vertical dimension when the mandible and Measures vertical dimension when the mandible and muscles muscles

involved are in physiologic function of speech.involved are in physiologic function of speech.

�� The The final testfinal test that we use to determine if the vertical that we use to determine if the vertical

dimension of occlusion that we have chosen is correct.dimension of occlusion that we have chosen is correct.

�� Measure VDO of existing denture and compare.Measure VDO of existing denture and compare.

Centric Occlusion(CO):Centric Occlusion(CO):

Definition: is the relation of opposing occlusal surfaces that provide maximum Definition: is the relation of opposing occlusal surfaces that provide maximum

intercuspation.intercuspation.

Centric Relation(CR):Centric Relation(CR):

Definition: a maxillomandibular relationship in which the condyles articulate with Definition: a maxillomandibular relationship in which the condyles articulate with

the thinnest avascular portion of their respective discs with the complex in the the thinnest avascular portion of their respective discs with the complex in the

anterioranterior--superior position against the slopes of the articular eminences.superior position against the slopes of the articular eminences.

Centric occlusion with teeth present is a toothCentric occlusion with teeth present is a tooth--toto--tooth relation,whereas centric tooth relation,whereas centric

CENTRIC RECORDSCENTRIC RECORDS

Centric occlusion with teeth present is a toothCentric occlusion with teeth present is a tooth--toto--tooth relation,whereas centric tooth relation,whereas centric

relation, is a static position, is a bone to bone relation.relation, is a static position, is a bone to bone relation.

11.. FunctionalFunctional ((Chew in)Chew in)2.2. GraphicGraphic ((Intraoral or extraoral tracings)Intraoral or extraoral tracings)3.3. StaticStatic((Interocclusal records)Interocclusal records)

a.a. Waxes (i.e AluWaxes (i.e Alu--wax)wax)b.b. Impression Compounds (ISO compound)Impression Compounds (ISO compound)c.c. ZOE pasteZOE paste

�� waxes are capable of making a record waxes are capable of making a record upon contact and the jaws can be upon contact and the jaws can be separated at once. separated at once.

CENTRIC RECORDSCENTRIC RECORDS

ISO Compound

separated at once. separated at once.

�� compound and ZOE must be maintained compound and ZOE must be maintained in contact until the material is hardin contact until the material is hard

�� waxes are easily distorted and unless waxes are easily distorted and unless extreme care is exercised when the records extreme care is exercised when the records are positioned, an error can occurare positioned, an error can occur

�� compound &compound & ZOE will break before they ZOE will break before they will distortwill distort

The technique can be divided into The technique can be divided into 2 2 steps:steps:

1.1. A tentative record using wax occlusion A tentative record using wax occlusion rims attached to accurate stable rims attached to accurate stable record bases.record bases.

2.2. Interocclusal check records with teeth Interocclusal check records with teeth arranged during the final tryarranged during the final try--in.in.

CENTRIC RECORDSCENTRIC RECORDS

AluAlu--waxwax

1.1. CR is a reference point in recording maxillomandibularCR is a reference point in recording maxillomandibularrelations.relations. It is independent of tooth contact. It allows usIt is independent of tooth contact. It allows us

CENTRIC RELATION RECORDCENTRIC RELATION RECORD

relations.relations. It is independent of tooth contact. It allows usIt is independent of tooth contact. It allows usto record the anteriorto record the anterior--posterior position of the mandible.posterior position of the mandible.

2.2. It can be verified and repeatedIt can be verified and repeated

3.3. It is a starting point for developing occlusion. For denture It is a starting point for developing occlusion. For denture occlusion CR=CO.occlusion CR=CO.

44.. It’s a functional position, although fleeting in natureIt’s a functional position, although fleeting in nature.

*** CR should be recorded at the proper VDO*** CR should be recorded at the proper VDO

RECORDING CENTRIC RELATION

•• Before making the final Before making the final

record check for record check for

interferences between interferences between

the record basesthe record bases

•• Adjust record bases as necessaryAdjust record bases as necessary

CENTRIC RELATION RECORDCENTRIC RELATION RECORD

•• Have patient practice Have patient practice

closing gently in a closing gently in a

retrudedretruded position before position before

making the final recordmaking the final record

Making CR records consists of Making CR records consists of

two phases:two phases:

1.1. Getting the entire Getting the entire mandible retrudedmandible retruded

--Bimanual techniqueBimanual technique

2.2. Positioning the Positioning the condylecondyle--disc assemblydisc assembly

in the in the uppermost anterior positionuppermost anterior position..