methods of determining vertical dimension of occlusion … · methods of determining vertical...
TRANSCRIPT
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..