The document discusses various aspects of jaw relations, specifically focusing on vertical jaw relations such as vertical dimension of occlusion and rest position. It outlines methods for recording these dimensions, including both mechanical and physiological techniques, and highlights the significance of physiologic rest position in dental practice. Additionally, the potential effects of varying vertical dimensions on patient comfort, aesthetics, and function are also addressed.

1. Dr Veena Saraf
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2. Definitions :
 Jaw relations : G.P.T-8
-Is any spatial relationship of maxilla to
mandible
 Types :
 Orientation jaw relation
 Vertical jaw relation
 Horizontal jaw relation
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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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5. INTEROCCLUSAL DISTANCE
/INTEROCCLUSAL REST SPACE
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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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11. Facial measurements
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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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13. Anatomic landmarks of the face
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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

17. Measurement of former
dentures
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18. Profile photograph
Disadv: angulation of photograph,
enlargement
Profile tracing: lead wiring adaptation
Casts of teeth articulated in occlusion
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19. Proportional measurement
Lower border of septum of nose – lower
border of chin =
outer canthus of eye – corner of mouth
(mandible at rest).
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20. phonetics
 Silverman closest speaking space
 Sibiliant sounds – s, z, sh, zh, fish, church,
judge
 Closest speaking space– measurement for
vertical dimension
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21. Niswonger’s method
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22. Tactile methods
1)Patient’s tactile sense
2)Boos bimeter gnathodynamometer
3)Swallowing threshold
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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

24. Labial fullness
Occlusal rim visibility

25. Anterior plane
Anteroposterior plane

26. Midline
The high lip line

27. The vertical dimension

28. Freeway space

29. Clinical significance of vertical jaw relation
Comfort
Esthetics
Phonetics
Functional efficiency

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

31. Effect of decreased vertical
dimension
1) Reduced masticatory efficiency
2) Poor esthetics
3) Cheek biting/ tongue biting/
lip biting
4) Denture look
5) Angular chelitis
6) Pain in TMJ
7) Coston’s syndrome (Eustachian
tubes)
8) Prognathism

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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
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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

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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.”