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2. JAW RELATIONS /
MAXILLOMANDIBULAR RELATIONS
“Any spatial
relationship of the
maxillae to the
mandible & the maxilla
to the base of the
cranium”

3. MAXILLOMANDIBULAR RELATIONSHIP
RECORD
“A registration of any possible
relationship of the mandible relative
to the maxillae. These records may
be made at any vertical , horizontal,
or lateral positions”

4. WHY IS RECORDING OF JAW RELATIONS
IMPORTANT ???
To design the dentures in such a way
that they function in harmony with
the 2 jaw bones and the joint in
between them i.e., the
Temporomandibular joint

5. Types of Jaw Relations
 Orientation Jaw Relation
 Vertical Jaw Relation
Horizontal Jaw Relation
- Centric Jaw Relation
- Eccentric Jaw Relation

6. “The orientation of the maxilla to the
base of cranium and to the imaginary
transverse axis passing through the
center of the condyles around which
the mandible may rotate within the
sagittal plane ”
ORIENTATION JAW RELATION

9. VERTICAL JAW RELATION
It involves the establishment of vertical
dimension of the dentures in harmony
with the appearance of the face , for
maximum functional efficiency and
patient comfort

10. HORIZONTAL JAW RELATION
It involves the relationship of mandible
to the maxillae in the horizontal plane
at centric and eccentric positions

11. ORIENTATION JAW
RELATION

12. This record gives the
angulation /inclination /tilt of the
maxilla in relation to the base of the
skull

13. BASE OF SKULL
MAXILLA
INCLINATION OF MAXILLA TO BASE OF
SKULL

14. Can be recorded with the help of a
FACE-BOW device
“Face-bow is a caliper like device used
to record the spatial relationship of the
maxilla to the opening axis of TMJ and
the base of skull and then transfer the
maxillary cast in the same relationship
to the opening axis of articulator”

15. PARTS OF A FACE BOW

16. ‘ U ‘ SHAPED FRAME

17. Forms the main frame of the face bow
Records the plane of the cranium
All other components are attached to
this frame with the help of clamps

19. EAR PIECES / PLUGS
2 small plastic plugs that fit the external
auditory meatus
Help to locate the opening axis of the
Temporomandibular joint / Hinge Axis

22. CLAMP

23. BITE FORK

24. Maxillary wax rim is attached to this
bite fork
Represents the plane of the maxilla
Attached to the the U frame with the
help of the clamp

30. ORBITAL POINTER
Indicates the point- Orbitale on the face

32. TYPES OF FACE BOW
Arbitrary Face bow
Fascia type
Ear piece type
Self centering Manual centering
Kinematic Face bow
Hanau spring bow

33. Once the maxilla is oriented to the
opening axis on the face , the entire
assembly is attached to the articulator
to transfer the maxillary cast on the
articulator in the same relationship to
the opening axis of the articulator

34. Quite some stressssssss !!!
That too just to attach a simple maxillary cast ???

35. VERTICAL JAW
RELATION

36. Vertical Jaw Relations/Dimensions are
expressed in terms of amount of
separation of maxillae and mandible
under specified conditions ,as viewed in
the frontal plane

37. Vertical Jaw Relations/Dimensions can
be classified into 2 types
Vertical
Dimension of
Rest
Vertical
Dimension of
Occlusion
Occlusion

38. Vertical Dimension of Occlusion (VDO)
When the natural teeth are present and in
occlusion ,the VDO is maintained or
established by them
When the natural teeth are lost & the patient
wears dentures, the VDO is established by
the two dentures when the teeth are in
contact
“The amount of separation of the jaws
when the teeth are in occlusion”

39. Therefore , the VDO must be
established for edentulous patients, such
that their denture teeth will come into
contact at the appropriate height

40. Vertical Dimension of Rest (VDR)
“The amount of separation of the jaws
when the mandible is in a
Physiologic Rest Position”
It is the position where the muscles that close
the jaws and those that open the jaws are in a
state of minimal contraction [function], just
enough to maintain the posture of mandible

41. VDR > VDO
VDR – VDO = FREEWAY SPACE
VDO VDR FREEWAY
SPACE
2-4mm

42. IMPORTANCE OF FREEWAY SPACE
•Assessing the vertical dimension of
occlusion of dentures
If the freeway space is < 2mm , it indicates
that the VDO is increased
If the freeway space is > 4mm , it indicates
that the VDO is decreased

43. •Relaxation of masticatory apparatus
and denture bearing areas
At rest position , when the teeth are not in
contact & freeway space is adequate, there is
no strain on the TMJ and minimal activity of
elevator and depressor muscles of the mandible
Allows for relaxation of the muscles and TMJs
and avoids fatigue

44. At the same time , if the dentures have no /
inadequate freeway space , the denture bearing tissues
are continuously and excessively loaded
Resorption of bone is aggravated

45. Methods for Determining Vertical
Dimension
Mechanical methods
Preextraction records
Ridge relations
Measurement of former
dentures
Physiologic methods
Physiologic rest position
Phonetics
Swallowing methods
Tactile sense & patient comfort

46. MECHANICAL METHODS

47. PRE-EXTRACTION METHODS
Profile radiographs
Can be used to assess the vertical dimension of
occlusion before extraction
The vertical dimension existing before the
removal of teeth can be used as a guide
establishing vertical dimension of the dentures

48. Casts of teeth in occlusion
The casts of teeth in occlusion give an
indication of the amount of space between the
ridges for the teeth of this size

49. Facial measurements
Devices like calipers or pair of dividers can be
used to make measurements in the middle &
lower 3rd
of the face e.g., from the base of the
nose to the base of the chin , before the
extraction of the teeth
These measurements can be used to establish
the same dimensions during denture fabrication

52. RIDGE RELATIONS
Incisive papilla to mandibular incisors
The distance of papilla from the incisal
edges of the mandibular incisors averages
approximately 4mm in natural dentition
The distance of papilla from the incisal
edges of the maxillary incisors averages
approximately 6mm in natural dentition

54. Therefore the mean vertical overlap of
the opposing incisors is about 2mm

55. Parallelism of Ridges

56. Parallelism of the maxillary & mandibular
ridges , plus a 5-degree opening in the
posterior region, often gives a clue as to
the appropriate amount of jaw separation

57. Parallelism of the maxillary & mandibular
ridges is natural
Parallelism of the maxillary & mandibular
ridges is favorable from a mechanical
point of view to prevent any
anteroposterior sliding of dentures during
function

58. Measurement of former dentures
Measurements can be made between the ridge
crests of the maxillary and mandibular dentures
with a Boley gauge
If the observations on the patients face indicate
that this distance is too short or too long , a
corresponding change can be made in the new
dentures

60. PHYSIOLOGICAL
METHODS

61. PHYSIOLOGIC REST POSITION
Registration of the jaw in physiological
rest position gives an indication of the
vertical dimension of occlusion
At the physiological rest position , there
should be a freeway space of 2-4mm
between the occlusal rims

62. This may not be an exact guide ;
therefore has to used in concordance with
other methods

63. PHONETICS
Phonetic tests include listening to speech
sound production & observing the
relationships of teeth during speech
The production of ch, s, & j sounds brings
the anterior teeth close together and
almost touch each other but do not touch

64. If the distance between the upper & lower
incisors is too large , it indicates that the
VDO is too small
If the anterior teeth touch when these
sounds are made / click together during
speech , it indicates that the VDO is too
large

65. SILVERMAN’S CLOSEST SPEAKING SPACE
Similar to the technique of phonetics
where ‘S’ sounds are used to assess the
vertical dimension
Range of 2-11 mm depending on the
functional range of the patient

66. The Freeway Space & Closest Speaking
Space are not the same
The freeway space is an assessment of VD
at rest ; while the speaking space is an
assessment of VD during function

67. ESTHETICS
The vertical relation of the mandible to
the maxillae also affects esthetics.
Normally the tone of the facial skin
should be the same throughout and for
this an appropriate vertical dimension is
necessary

68. If the vertical dimensions of the dentures
is excessive , it will lead to stretched
appearance of the facial skin
If the vertical dimensions of the dentures
is too less , it will lead to wrinkled
appearance of the facial skin

69. However , this guide is a relatively
unreliable one ; therefore should be used
with caution or in combination with
other methods

70. Whether the face is appearing long or
otherwise is subjective
If the facial skin of the patient is already
wrinkled , one may be tempted to
increase the vertical dimension excessively

71. SWALLOWING THRESHOLD
The position of the mandible at the
beginning of the swallowing act has been
used as a guide establish the vertical
dimension of occlusion
When a person swallows, the teeth come
together with a very light contact at the
beginning of the swallowing

72. If the denture teeth fail to contact during
swallowing , the VDO is excessively
reduced

73. TACTILE SENSATION
The patient’s tactile sense can be used as a
guide to the determination of the VDO
The problem with this method relates to
presence of foreign objects in the palate &
the tongue space which can obscure the
patient's judgment

74. HORIZONTAL JAW
RELATION

75. Horizontal Jaw Relation is the
relationship of the maxilla to the
mandible in the horizontal plane i.e., in
the anteroposterior and lateral directions

76. Horizontal Jaw Relations can be classified
into 2 types
Eccentric Relations
Centric Relation

77. CENTRIC JAW RELATION
The relationship of mandible to maxilla ,
when the mandible is in the most
posterior / retruded ,unstrained position
in relation to the maxilla, at an
established vertical dimension
WHAT DOES THIS STATEMENT
IMPLY ???

78. “The Maxillomandibular relationship in
which the condyles articulate with the
thinnest avascular portion of the articular
disc & the complex (of articular disc and
the head of condyle) braced
anterosuperiorly against the (posterior)
slopes of the articular eminence”

79. When the natural teeth are present, the
proprioceptive impulses from the teeth
guide the movement of the mandible so
the teeth can come in occlusion in a
comfortable position

80. When the natural teeth are absent, the
proprioceptive impulses from the the
Temporomandibular joint guide the
movement of the mandible so that the
mandible can close in a comfortable &
unstrained position

81. It is at this comfortable position , the
denture teeth should come in occlusion
with each otherc
The comfortable position is the Centric
Relation Position
The occlusion of the denture teeth in this
comfortable position is the Occlusion at
Centric Relation Position / Centric
Occlusion

82. SIGNIFICANCE OF CENTRIC RELATION
POSITION
•The recording of the Centric relation
position is the starting point for
developing occlusion in the complete
dentures
•It is a bone to bone relation
•It is a hinge position

83. •It is an ideal arch to arch relation and an
optimum functional position of the jaws
for the health, comfort & function of the
TMJ and musculature
•During swallowing the mandible is at
/near the centric relation position
•It is a learnable , repeatable &
reproducible position

84. Although the position is reproducible , it
is difficult to record it with sufficient
accuracy in edentulous patients
BIOLOGICAL
DIFFICULTIES
PSYCHOLOGIC
DIFFICULTIES
MECHANICAL
DIFFICULTIES

85. Instructions can be given to assist patient
to retrude the mandible
“Let your jaw relax , pull it back ,and close
slowly and easily on your back teeth”
“Get the feeling of pushing your upper jaw
out & closing your back teeth together”

86. Instruct the patient turn the tongue
backwards towards the posterior part of the
hard palate
Instruct the patient to protrude & retrude the
mandible repeatedly while holding his or her
fingers lightly against the chin

87. METHODS TO RECORD THE
CENTRIC JAW RELATIONS
Interocclusal
Check records
Wax Squash
Bite
Pressure – less
method
STATIC METHODS

88. Can be made at the stage of Try- in of the
waxed up trial dentures after the arrangement
of teeth
INTEROCCLUSAL CHECK RECORDS

89. A softened sheet of Aluwax is placed between
the upper & lower teeth on the trial dentures
The patient is guided into centric relation
position
The patient is then asked to close in that
position without contacting the teeth

90. WAX SQUASH BITE
Involves placement of a horse-shoe shaped
roll of softened wax between maxillary &
mandibular rims and having the patient close
the jaws in centric relation

91. PRESSURE - LESS METHOD
The occlusal rims are adjusted to establish the
correct vertical dimension
The patient is trained to close in centric
relation position
The wax can then be sealed in centric relation
position using Nick & Notch method / Staple
pins

92. These methods use functional movements of
the jaw to record the centric relation
The patient is asked to perform lateral and
protrusive movements in order to identify the
centric relation position of the mandible
NEEDLE HOUSE
TECHNIQUE
PATTERSON’S
TECHNIQUE
FUNCTIONAL METHODS

93. These methods are called so because they
use graphs / tracings to record various jaw
movements & centric jaw relation position
Done with the help of tracing apparatus
2 types of tracings
ARROW POINT TRACING PANTOGRAPHIC TRACING
One dimensional tracing Three dimensional tracing
GRAPHIC METHODS

94. RADIOGRAPHIC METHODS
Lateral cephalometric radiograph can be used
to record the centric relation position by
studying the position of the condyles in relation
to the articular eminence

95. ECCENTRIC JAW RELATION
Any relationship of the mandible to the
maxilla other than centric relation
It includes the recording of protrusive
and lateral movements of the mandible
The basic purpose is to be able to
reproduce these movements on the
articulator

96. TECHNIQUE FOR
RECORDING JAW
RELATIONS

97. PATIENT POSITION
The patient should be relaxed, with the trunk
upright ,and head unsupported

98. ADJUSTMENT OF OCCLUSAL PLANE & VERTICAL
HEIGHT OF THE MAXLLARY RIM

99. OCCLUSAL PLANE SHOULD BE FLAT

100. THE OCCLUSAL PLANE OF MAXILLARY RIM IS
EVALUATED USING FOX’S PLANE

101. ANTERIORLY THE OCCLUSAL PLANE SHOULD BE
PARALLEL TO THE INTERPUPILLARY LINE

102. POSTERIORLY THE OCCLUSAL PLANE IS MADE
PARALLEL TO THE ALA-TRAGUS LINE

103. ALA-TRAGUS LINE
A line drawn from the superior portion of
the tragus to the inferior border of the ala
Also referred to as the ‘CAMPER’S PLANE’

104. THE ANTERIOR VISIBILITY SHOULD BE 1-2mm AT THE
RESTING POSITION OF THE UPPER LIP

105. ADJUSTING THE VERTICAL DIMENSION

106. Once the occlusal plane of maxillary rim is
adjusted corrected, YOU SHOULD NOT
TOUCH THE PLANE AGAIN !!!
The vertical dimension is established by
adjusting the height of the mandibular wax
rim

107. FREEWAY SPACE OF 2-4 mm AT PHYSIOLOGIC
REST POSITION

108. The patient is asked to swallow
Relax his lips and cheeks muscles
Lightly contact the lips
The lips are then parted to evaluate the
freeway space
HOW TO CHECK FOR THE CORRECTNESS OF THE
VERTICAL DIMENSION
I.

110. The patient can be asked to pronounce
words with sounds of ‘M’ instead of
swallowing action and the same procedure
can be repeated
Pronunciation of sibilants (words with
sounds of ‘S’) with clarity can also be used to
evaluate the correctness of VD
II.

111. The distance between the most prominent
point on the nose and the most prominent
point on the chin at rest and in occlusion can
be measured and the difference can be
calculated to evaluate the freeway space
e.g., VDR - 65 mm
VDO - 62 mm
VDR – VDO = FREEWAY SPACE=3mm
III.

112. .
.

113. The distance between base of the nose and
the base of the chin at rest and in occlusion
can also be used

115. THE MANDIBULAR RIM AFTER ADJUSTING THE
HEIGHT

116. THE RIMS SHOULD CONTACT EACH OTHER UNIFORMLY
ALONG THE FULL LENGTH AT THE CORRECT VERTICAL
DIMENSION

117. APPEARANCE OF THE PATIENT AFTER ESTABLISHING THE
CORRECT VERTICAL DIMENSION

118. TRANSFERRING THE FACIAL MIDLINE ON THE MAXILLARY
RIM

119. MARKING THE CANINE LINES ON THE MAXILLARY RIM

120. RECORDING THE CENTRIC RELATION
NICK & NOTCH
TECHNIQUE
Static record

121. NOTCH

122. ‘V’ shaped space created on the maxillary
rim in the 1st
molar region crossing the full
width of the rim
Function : to prevent Anteroposterior
movement / sliding during centric relation
recording

123. NICK

124. ‘V’ shaped space created on the maxillary
rim in the 2nd
premolar region not crossing
the full width of the rim
FUNCTION : to prevent Lateral movement /
sliding during centric relation recording

126. TROUGH

127. An area of depression created on the
mandibular rim in direct apposition to the
nick & notch on the maxillary rim
FUNCTION: to provide space for the bite
registration paste that will enter the nick and
notch

128. NICK NOTCH
TROUGH

129. BITE REGISTRATION
PASTE FILLED IN THE
TROUGH
The rims are then placed in patients mouth &
guided to close in centric relation

130. BITE REGISTRATION PASTE ENTERS THE
NICK & NOTCH
The rims are locked by the bite registration paste

131. TROUGH PREPARED WITH A SHARP KNIFE

132. PATIENT GUIDED INTO CENTRIC RELATION & ASKED
TO CLOSE

133. THE PATIENT CLOSES IN CENTRIC RELATION