3. VERTICAL JAW RELATIONS
They are classified as :
Vertical dimension of occlusion (VDO)
Vertical dimension of rest position (VDR)
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4. Vertical dimention
Vertical dimension at rest: (GPT-8)
The distance b/w two selected points measured
when the mandible is in the physiologic rest position.
Vertical dimension at occlusion: (GPT-8)
The distance b/w two points when the occluding
members are in contact.
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6. Physiologic rest position
GPT-8: postural position of
mandible when an individual is
resting comfortably in an upright
position and the associated
muscles are in a state of minimal
contraction activity.
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7. SIGNIFICANCE OF PHYSIOLOGIC
REST POSITION
1)Bone - bone relation in vertical direction
2)Absence of pathosis - relation - constant
3)Position - recorded & measured
4)Determining vertical dimension at
occlusion
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8. Common factors to consider while
recording vertical jaw relation
Position of mandible – influenced by gravity
Patient should be calm, cool, & relaxed
Difficult in neuromuscular disturbances
No one method – accepted
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9. Variable Rest position
dimension
Patient supine Reduced
Head tilted back Increased
Head tilted forward Reduced
Insertion of lower denture or
record block
Increased
Stress Reduced
Pain Reduced
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10. Recording rest position
Facial measurements
Tactile sense
Measurements of anatomical
landmarks
Speech
Facial expression
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12. Tactile sense
Patient -stand erect & open the mouth wide
open –strain
Opening- uncomfortable instruct the
patient - close until the jaws -comfortable
relaxed position
Distance between the points of reference
compare -after swallowing
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14. Method of determining the
vertical dimension
Mechanical methods
Ridge relationship
Pre extraction records
Measurements from former dentures
Physiological methods
phonetics
tactile sense
swallowing threshold
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15. 1) Mechanical methods:
Ridge relation: a) distance of
incisivemandibular incisors
b) parallelism of ridges
Measurement of former dentures
Pre-extraction records-
Profile radiographs
Profile photographs
Profile tracing
Casts of teeth in occlusion
Facial measurements
16. Mechanical methods
Ridge relation:
Incisive papilla – stable landmark
Disadv: absence of lower anterior teeth – cannot be used.
Ridge parallelism
•Clinical crowns of anterior & posterior teeth- same length
•Paralleling of max. & mandibular ridges plus 5 degree opening.
(Sears)
Disadv: teeth are lost at different times
23. Clinical procedure for recording Vertical
jaw relation
Testing the maxillary record block
Retention
Stability
Trimming the maxillary occlusal rim
Labial fullness
The height of the occlusal rim
The anterior plane
The anteroposterior plane
Guide lines
The centre line or midline
The high lip line
The canine lines
Trimming the mandibular occlusal rim
The vertical dimension
Freeway space measurement
30. Effect of increased vertical dimension
1) Increased risk of trauma- clenching of teeth
2) Discomfort to patient
3) Teeth are liable to contact – causing clicking
during speech
4) Trauma & pain – basal seat areas of denture
5) Loss of freeway space - muscular fatigue
6) Elongated appearance of face
7) Bone resorption
8) Loss of retention & stability of dentures
33. Method of determining the
vertical dimension
Mechanical methods
Ridge relationship
Pre extraction records
Measurements from former dentures
Physiological methods
phonetics
tactile sense
swallowing threshold
33
34. 1) Mechanical methods:
Ridge relation: a) distance of
incisivemandibular incisors
b) parallelism of ridges
Measurement of former dentures
Pre-extraction records-
Profile radiographs
Profile photographs
Profile tracing
Casts of teeth in occlusion
Facial measurements
36. .
“Stand and die in
your own
strength; if
there is any sin
in the world, it
is weakness;
avoid all
weakness, for
weakness is
sin, weakness is
death.”