8. Occlusal Vertical Dimension (OVD)
• Distance between maxilla & mandible
when teeth or wax rims contact in
centric occlusion
9. Vertical Dimension of Rest
The postural relation of the
mandible to the maxilla when
the patient is resting
comfortably in an upright
position and the condyles are
in a neutral unstrained position
in the glenoid fossa
10. Physiologic Rest Position (PRP)
• At rest, lips barely
touching
• Occlusion rims
should not touch
Intraorally no contact
Use Boley Gauge,
not ruler
12. Measuring Occlusal Vertical Dimension
• Measure the distance between dots
– VDR
– VDO
– Difference is IOS
Inter Occlusal Rest
Space
Measurements change each day (position
of dots)
13. Physiologic rest position is:
•The postural position of the
mandible when an individual
is resting comfortably in an
upright position and the
associated muscles are in a
state of minimal contractile
activity. and
the condyles are in a
neutral unstrained position
in the glenoid fossa.
14. Isometric contraction
It is contraction of muscle
without shortening
Ring of closing,
opening and post
vertebral muscles.
Elevator muscles
Contract isometrically
to keep the mandible at
rest (tension without
shortening)
15. 1- Patient sitting comfortable upright
position unsupported by a head rest.
16. 2. Mark small dots on the nose and the chin to
serve as reference points. Ask the patient to
swallow and relax the jaw several times.
3. Measure resting vertical dimension with upper
rim only in mouth to provide lip support.
17. 4. Use a tongue depressor blade to record the
distance between the reference points when
the patient's jaws are in the physiologic rest
position (VDR). It should be relatively constant
after several repetitions.
18. 5. Trim the lower rim with a heated spatula or
knife. To meet the upper evenly in retruded
position at correct vertical dimension
6. If you are having difficulty, check to see if the
acrylic record bases are touching posterior to
the to the wax occlusion rims.
19. 7. Replace the mandibular record base in the
mouth and verify using the tongue blade that
you have established the vertical dimension of
occlusion you desire.
21. 2 to 4 mm
Vertical Dimension
V D R - F W S = V D O
22. Measuring Occlusal Vertical Dimension
• Open and close until rims
touch
• Measure distance between
dots (OVD)
• Measurement will be
different each appointment
23. Establishing OVD
Phonetics Test
• Closest Speaking Space
• Confirms OVD
• Sibilant sounds ("s", "z", sh", ch")
• Rims should be at least 1 mm apart
• Don’t worry about sounds yet
24. Excessive OVD Wax Rims Too High
•Insufficient interocclusal distance
•Remove wax from one or both of the
rims
– Use large wax formers
– #5 & #7 wax spatulas
– Red-handled knife
– Bunsen burner and torch
25. 8. Other clinical aids in determining the vertical
dimension of occlusion are facial appearance
and phonetics.
If the OVD is too great, the lower
third of the face will appear longer
and the lips will be incompetent,
contraction of mentalis
If too small, the vermilion border
will become thin and wrinkles will
occur on the lips. The chin will
have a protruded appearance.
26. 9. Maintain even contact throughout all
occluding surfaces of the hard occlusion
blocks at the predetermined vertical
dimension of centric occluding relation.
27. Wax Rim Adjustment at OVD
• Flat even contact
along entire occlusal
surface
• If uneven contact,
patient may be forced
into eccentric
position
28. no undercuts
10.The upper occlusion rim should be coated
with a separating medium such as Vaseline
to avoid adhesion to the softened lower rim
at the next step.
29. Eliminating Record Base or
Wax Rim Interferences
• Patient in Centric
Position
• Scribe three
widely separated
lines between
maxillary &
mandibular rims
30. 1- Central line (midline)
2- The corner line (canine line)
3- The high lip line and low lip line
32. Variables Affecting V D R :
Short Term Variables :
1. Position of the patient's head .
2. Respiration.
3. Stress Situations .
Long Term Variables :
1. Loss of the properioceptives impulses from the
periodontal ligament.
2. Age.
35. VALUE OF VERTICAL DIMENSION
Biological importance of correct registration of
the occlusal vertical dimension; the patient can
1 - Masticate his food efficiently.
2 - Speak without impediment.
3 - Present a normal facial appearance.
4 - Experience a minimum amount of
discomfort in using his dentures.
36. 1- inharmonious facial proportions (Appearance).
2- Flexor muscles are in constant strain.
3- The lips are unnaturally separated and have a
strained appearance.
4- The free-way space will be obliterated, inability
to find comfortable resting position.
5- Clicking of teeth may occur during speech and
mastication.
Sequel Of Improper Registration Of V.D.0.
A . High Vertical Dimension Of Occlusion :
37. Sequel Of Improper Registration Of V.D.0.
6- Generalized soreness of the residual ridge.
7. Difficulty in swallowing and gagging
sensation (Discomfort).
8. Loss of biting power and muscular fatigue.
9. Interference with speech .
10. Pain under the basal seat and trauma to
the supporting structures .
11. Accelerate bone resorption.
A . High Vertical Dimension Of Occlusion :
41. Establishing too little V.D.
1- Extensor muscles are strained.
2- Facial appearance is distorted.
3- Corners of the mouth may be
inflamed ( angular chielitis ).
4- Pain in temporomandibular joint.
5- Cheek biting.
6- Inefficiency: reduces biting force
42. Trouble in the T.M.J.
The symptoms of the joint due to reduced
V.D. are manifested by
• Obscure pains and discomfort,
• Clicking sounds of TMJ,
• Headaches and neuralgia running in
the ear.
These symptoms may be resulted from
pressure on the tympanic nerve.
47. In summary
Determination of Vertical Dimension of Centric
Occluding Relation
• Patient sitting in an upright
• Vertical Dimension of Rest (Physiologic Rest
Position) (PRP)
• Interocclusal Distance (ID)
• Occlusal Vertical Dimension (OVD)
• Establishing too little V.D.
• High Vertical Dimension Of Occlusion
• Establish facial contour, The central line,
The high lip line, The corner lines.