Temporomandibular joint described in detail along with prosthodontic implications under the headings INTRODUCTION DEFINITION PECULIARITY OF TMJ DEVELOPMENT ANATOMIC COMPONENTS VASCULAR SUPPLY INNERVATIONS MOVEMEN BIOMECHANICS PROSTHODONTIC IMPLICATIONS REFERENCES

1. GOOD AFTERNOON

2. TEMPOROMANDIBULARJOINT ANATOMY
PRESENTED BY:
FALAK NAZ
PG 1ST YEAR
DEPTT OF
PROSTHODONTICS
, CROWN
&BRIDGE,GDC SGR

4.  INTRODUCTION
 DEFINITION
 PECULIARITY OF TMJ
 DEVELOPMENT
 ANATOMIC COMPONENTS
 VASCULAR SUPPLY
 INNERVATIONS
 MOVEMEN
 BIOMECHANICS
 PROSTHODONTIC IMPLICATIONS
 REFERENCES

7. A JOINT is
•The place of union
of two or more
bones—GPT 8

8. A. Fibrous
B. Cartilaginous
C. Synovial
Joints can be classified as;

9. DEFINITION
 The articulation
between the
temporal bone and
the mandible.
It is a bilateral
diarthrodial,
bilateral ginglymoid
joint—
GPT 8

10. Also known as CRANIO-MANDIBULAR
ARTICULATION
 Considered as a ginglymoarthrodial SYNOVIAL joint
 Classified as a compound joint
 Multiaxial joint

11. Peculiarityof TMJ
1. Bilateral diarthrosis
2. Articular surface covered by
fibrocartilage instead of hyaline cartilage
3. Only joint in human body to have a rigid
endpoint of closure

12. Peculiarityof TMJ…….
4. In contrast to other diarthrodial joints TMJ
is last joint to start develop, in about
7th week in utero.
5. Develops from two distinct
blastema.

13.  At week 12 of gestation:
 TEMPORAL OR GLENIOD BLASTEMA
 Ossifies and becomes glenoid fossa
 CONDYLARBLASTEMA
 Becomes the condylar cartilage
 Clefts are formed
 lower joint cavity
 upper joint cavity
DEVELOPMENT

14. 1. Primitive articular disc
2. Upper cleft
3. Lower cleft
4. Temporal blastema
5. Condylar blastema

15. A - Fibrous layer
B - Reserve zone
C - Proliferative zone
D - Hypertrophic zone
E - Calcifying zone
F - Bone
{HISTOLOGY}

16. Anatomic
Components

17. COMPONENTS
PASSIVE BONY
COMPONENTS
JOINT CAPSULE
LIGAMENTS
DISC
ACTIVE MUSCLES

18. CRANIAL
COMPONENT
Articular fossa
MUSCLE
AREA OF INTEREST
LIGAMENT DISC
MANDIBULAR
COMPONENT
condyle

19. INDIVIDUALCOMPONENTS
BONE
- Fossa mandibularis ossis
temporalis
- Capitulum mandibula
(condyle )
- Tuberculum articulare
( articular eminence )
CAPSULE & LIGAMENTS

20. ARTICULAR DISC
MUSCULAR
COMPONENT

21. THEMANDIBULARCONDYLE
Processus condyloideus
-Mediolateral : 15 – 20 mm
-Anteroposterior : 8 – 10 mm
-Anterior view : medial & lateral poles,
the medial pole more prominent
-The actual articulating surface ~
extends anteriorly
and posteriorly to the most
superior
aspect
( P > A )

22. NECK CONSIDERED AS
FUSE BOX OF CONDYLE

23. If the long axes of
two condyles are
extended medially,
they meet at
approximately the
basion on the
anterior limit of the
foramen magnum,
forming an angle that
opens toward the
front ranging from
145° to 160°

24. The articular surface lies on its
anterosuperior aspect, thus
facing the posterior slope of the
articular eminence of the temporal
bone.
E: Articular eminence; ENP: entogolenoid
process; t:articular tubercle; CO: condyle;
POP: postglenoid process; LB: lateral border
of the mandibular fossa; PEP: preglenoid
plane; GF: glenoid fossa; CP: condylar
process

25. -
MANDIBULAR FOSSA
THE SQUAMOUS PORTION OF THE TEMPORAL BONE
(CONCAVE )
ANTERIOR : A CONVEX BONY PROMINENCE
( TUBERCLE ) = ARTICULAR EMINENCE
POSTERIOR : SQUAMOTYMPANIC FISSURE (M-L)
~ ANTEROMEDIAL : PETROSQUAMOUS FISSURE
~ POSTEROMEDIAL : PETROTYMPANIC FISSURE
E: Articular eminence; ENP: entogolenoid
process; t:articular tubercle; Co: condyle;
pop: postglenoid process; lb: lateral border of
the mandibular fossa; PEP: preglenoid
plane; GF: glenoid fossa; Cp: condylar
process

26. The posterior roof is thin ~ not designed
to sustain heavy force
The articular eminence consists of thick
dense bone ~ to tolerate such forces
The steepness of the articular eminence
surface ~ dictates the pathway of the
condyle
-CONDYLAR GUIDANCE.

27. Medial poles located in medial third of the fossa

28. This is the entire transverse bony
bar that forms the anterior root of
zygoma.
Articulareminence:
This articular surface is most heavily
traveled by the condyle and disk as
they ride forward and backward in
normal jaw function

29. Mandibular condyle
Squamous temporal bone
Articular eminence

30.  It is a BICONCAVE
FIBROCARTILAGINOUS structure
located between the mandibular
condyle and the temporal bone.
 It FUNCTIONS to accommodate a
hinging action as well as the
gliding actions .
ARTICULARDISC

32.  The ARTICULAR DISC is a
roughly oval, firm, fibrous
plate.
PARTS:
1. ANTERIOR BAND = 2 mm
thick
2. POSTERIOR BAND = 3 mm
thick,
3. INTERMEDIATE BAND of 1
mm thickness.
4.More posteriorly there is a
BILAMINAR OR
RETRODISCAL REGION.

33. • SHAPED like a PEAKED CAP
that divides the joint into a
 larger upper compartment
and
 a smaller lower compartment.

34. • Hinging movements take place in the lower
compartment and gliding movements take place
in the upper compartment.
• The superior surface of the disc - SADDLE-SHAPED
to fit into the cranial contour,
• The inferior surface - CONCAVE
to fit against the mandibular condyle.

36. ATTACHMENTS OF DISC
•POSTERIORLY:
RETRODISCAL TISSUE
- It is a loose connective tissue
region that is highly
vascularized and innervated.

37. AV SHUNT ALSO k/a
VASCULAR KNEE

38. SUPERIOR : superior retrodiscal
lamina
( CONTAINS MAINLY ELASTIC
FIBERS ]
It attaches the disc posteriorly to
the tympanic plate It prevents
slipping of the disc while yawning.
INFERIOR : inferior retrodiscal
lamina
( COMPOSED CHIEFLY
COLLAGENOUS FIBERS )
It attaches the inferior border of
the posterior edge of the disc to the
posterior margin of the articular
surface of the condyle.
It prevents excessive rotation of the
disc over the condyle.

39. ANTERIORLY:
Anterior region of the disc is
attached to the capsular ligament
- Anterio-Superior : anterior
margin of the articular surface of
the temporal bone
-Anterio-Inferior : anterior margin
of the articular surface of the
condyle
 Anteriorly the disc is also
attached by tendinous fibers to the
superior lateral pterygoid muscle

41.  ON SAGITTAL MR
IMAGING, THE DISK -
biconcave structure with
homogeneous low signal
intensity.
 The anterior band lies
immediately in front of the
condyle
• posterior band and
retrodiskal tissue
are best depicted in
the open-mouth
position.

42. LubricationoftheJoint
 Comes from Synovial fluid
 The synovial fluid comes from two sources: first, from
plasma by dialysis, and second, by secretion from type
A and B synoviocytes)
 Contrast radiography studies have estimated that the
upper compartment could hold approximately 1.2 ml
of fluid without undue pressure being created, while
the lower has a capacity of approximately 0.9ml.

43.  It is clear, straw-colored viscous fluid.
 It diffuses out from the rich cappillary network of the
synovial membrane.
Contains:
 Hyaluronic acid which is highly viscous
 May also contain some free cells mostly macrophages.
Functions:
 Lubricant for articulating surfaces.
 Carry nutrients to the avascular tissue of the joint.
 Clear the tissue debris caused by normal wear and
tear of the articulating surfaces.

44. Two mechanisms of the lubrication :
1. Boundary lubrication
Prevents friction in the moving joint
2. Weeping lubrication
Eliminates friction in the compressed but not
moving joint

45. LIGAMENTS

46. PRIMARY LIGAMENTS
1.Capsula articularis ~ CAPSULAR LIGAMENT
- THIN SLEEVE OF FIBROUS TISSUE surrounding the
entire TMJ
- Superior attachment
~ the borders of the
articular surface of the mandibular fossa
and articular eminence
- Inferior attachment
~ collum mandibula

47.  This capsule is reinforced more laterally by an
external TMJ ligament, which also limits the
distraction and the posterior movement of the
condyle.
 Medially and laterally-
blends with the
condylodiscal ligaments.

48.  Anteriorly, the capsule has an
orifice through which the
lateral pterygoid tendon
passes. This area of relative
weakness in the capsular
lining becomes a source of
possible herniation of intra-
articular tissues, and this, in
part, may allow forward
displacement of the disk.

49. - Function :
~ to resist any medial, lateral
or inferior forces that tend
to separate or dislocate the
articular surface
~ to retain the synovial
fluid
~ propioception

50. 2.Collateral ( discal ) ligaments
- From medial and lateral borders of the disc to the
poles of the condyle
~ the medial discal ligament
~ the lateral discal ligament
- Dividing the joint mediolaterally into superior and
inferior joint
cavities

52.  Permit the disc to be rotated A-P on
the articular surface of the condyle
These ligaments are RESPONSIBLE FOR THE
HINGING MOVEMENT BETWEEN THE
CONDYLE AND THE ARTICULAR DISC
- They have a vascular supply and are
innervated
- Function :
 Allow the disc to move passively with the
condyle as it glides A - P

53. 3.Temporomandibular ligament
- It lies at the lateral aspect of the capsular
ligament
- Composed of two parts :
 Outer oblique portion
From the outer surface of the articular
tubercle and zygomatic process postero
inferiorly to the outer surface of the
condylar neck
FUNCTION ~
it resists excessive dropping of the condyle so limiting the extent of
mouth opening

55. A, As the mouth opens, the teeth can be separated about 20 to 25 mm (from A to B)
without the condyles moving from the fossae. B, TM ligaments are fully extended. As
the
mouth opens wider, they force the condyles to move downward and forward out of the
fossae. This creates a second arc of opening (from B to C).

56.  Inner horizontal portion
From the outer surface of the articular tubercle
and zygomatic process posteriorly and
horizontally to the lateral pole of the condyle
and posterior part of the articular disc.
FUNCTION ~
It limits posterior movement of the condyle
and disc
UNIQUE FEATURE OF TML:
LIMITS ROTATIONAL MOVEMENT ---FOUND ONLY IN HUMAN

57. ACCESORY LIGAMENTS
4.Sphenomandibular ligament
 From the spine of the sphenoid bone
& extends downward to
lingula mandibula

58. 5.Stylomandibular ligament
- The second accesory
ligament.
- This is a specialized dense,
local concentration of deep
cervical fascia
- From the styloid process &
extends downward and
forward to the angle and
posterior border of the
ramus mandibula.

59.  -FUNCTION
 It limits excessive protrusive movements of the
mandible
 This ligament becomes tense only in extreme
protrusive movements.

61. DISCO-MALLEOLAR LIGAMENT
The disco malleolar ligament (PINTO
LIGAMENT) was described by
pinto(1962) as a connection between the
malleus & the medial wall of joint capsule.
However, a separate ligament can be
demonstrated here in only 29% of
temporo mandibular joints .

64. MUSCULAR COMPONENT

65. PRIMARYMUSCLESOF
MASTICATION
• MASSETER
• TEMPORALIS
• LATERAL PTERYGOID
• MEDIAL PTERYGOID

67. SECONDARYMUSCLES
OFMASTICATION
•Suprahyoid muscles
•Infrahyoid muscles

68. SUPRAHYOID GROUP
•DIGASTRIC
•MYLOHYOID
•GENIOHYOID
•STYLOHYOID

69. INFRAHYOIDMUSCLES
 STERNOHYOID
THYROHYOID
OMOHYOID
STERNOCLEIDOMASTOID AND TRAPEZIUS
&

70.  Skeletal
 Voluntary
 Multipennate
 Quadrate
 Antigravity
 Elevator
MASSETER

72. ELEVATION Of MANDIBLE By MASSETER

73. TEMPORALIS
 FAN SHAPED
 BIPENNATE MUSCLE
 SKELETAL
 VOLUNTARY

74. Anterior fibers ELEVATION
Posterior fibers RETRUSION
Functionsoftemporalismuscle

75.  a Thick muscle
 Quadrate
 Multipennate
 Skeletal
 Voluntary
MEDIALPTERYGOIDorINTERNALPTERYGOID
PTERYGOIDEUS MEDIALIS
 Consists 2 heads ( caput )
- Caput superficial
-Caput profundus

76. FUNCTION:
- Contraction ~ mandible is
ELEVATED and the teeth are
brought into contact
- It is also active in
PROTRUDING the mandible
- Unilateral contraction ~
mediotrusive movement of
the MANDIBLE

77. LATERAL PTERYGOID
PTERYGOIDEUS LATERALIS
It consists 2 heads or bellies
with different function
Caput superior
Caput inferior

78. FUNCTION :
-While the inferior active during
opening, the superior remains
inactive, becoming active only in
conjunction with the elevator
-The superior lateral pterygoid active during
power stroke

79. BLOODSUPPLY
 ARTERIES:
BRANCHES FROM SUPERFICIAL TEMPORAL
AND MAXILLARY ARTERIES
 VEINS:
VEINS FOLLOW ARTERIES

80. INNERVATION
 Movements of synovial joint are initiated & effected by muscle coordination.
 Achieved in part through sensory innervation.
 Hilton’s Law:
 The muscles acting on a joint have the same nerve supply as the joint.
 Therefore: Branches
of the mandibular division of the fifth cranial nerve supply the TMJ (auriculotemporal, deep
temporal, and masseteric) supply the joint.

81. MOVEMENTS

82. Movements
 Rotational / hinge movement in first 20-
25mm of mouth opening
 Translational movement after that when
the mouth is excessively opened.

84. 1. Depression Of Mandible
 Lateral pterygoid
 Digrastric
 Geniohyoid
 Mylohyoid

85. 2. Elevation of Mandible
 Temporalis
 Masseter
 Medial
Pterygoids

86. 3. Protrusion of Mandible
 Lateral Pterygoids
 Medial Pterygoids

87. 4. Retraction of Mandible
 Posterior fibres of Temporalis

89. 1. History taking
2. Measuring maximum interincisal opening
3. Palpation of pretragus area ; the lateral aspect of TMJ
4. Intra – auricular palpation ; the posterior aspect of TMJ
5. palpation of masseter muscle
6. Palpation of lateral pterygoid muscle
7. Palpation of medial pterygoid
8. Palpation of temporalis
CLINICAL EXAMINATION OF TMJ

90. •The maximum opening
distance between the incisal
edges of upper and lower
incisor is measured using scale
, Boley gauge or ruler
•Normal opening – 40 to 55
mm
•Normal opening can also be
estimated by patient’s own finger
•Normal : three finger end on end
•Two finger opening reveals reduction
in opening but not necessarily
reduction in function
•One finger opening indicates reduced
function

91. Normal lateral
range of
movement is
>7-10mm
PROTRUSIVE-
10-14mm

93. Palpation of pretragus area ; the lateral aspect of TMJ

94. TMJ can also be palpated through anterior wall of external auditory
meatus

95. PALAPATION OF MUSCLES

96. Temporalis muscle can be seen and readily palpated throughout entire
length and breadth when the patient’s teeth are firmly clenched.

97. Palpate multiple areas of
the masseter muscle
PALAPTION OF MASSETER
As with temporalis muscle,it can be
located when patient’s jaw are
forcibly

98. PALPATION OF MEDIAL PTERYGOID
Anterior part of insertion can be palpated by placing the finger at 45 degrees in
the floor of the patients mouth near base of the relaxed tongue.
The opposite hand can be used to extraorally to palpate posterior and inferior
portions of insertion.
Body of the muscle can be palpated by rotating the index finger upwards against
the muscle to near its origin on the tuberosity.

99. PALPATION OF LATERAL PTERYGOID MUSCLE
The muscle is palpated by using the little or index finger and placing it lateral to
maxillary tuberosity and medial to coronoid process.The finger presses upwards
and inwards and a painful response can be determined .

100. PROSTHODONTIC IMPLICATIONS&
BIOMECHANICS OF TMJ

101. Definition
 Study of function and structure of
biological system
-BIOMECHANICS

102. Two joint systems in one joint
 Condyle Disc complex
 ROTATIONAL MOVEMENT
 Condyle disc complex
functioning against the fossa
 TRANSLATORY MOVEMENTS

103. At rest condyle rests on posterior band; beginning of translation, it lies over the intermediate
zone; when mouth is fully open, it lies over the anterior band.

104. STOMATOGNATHIC
SYSTEM
TMJ
NEURO
MUSCULATURE
TEETH
LIGAMENTS

105. BASIC PRINCIPLE--Dawson
•Neuromuscular harmony depends on structural harmony
between the occlusion and temporomandibular joints.

106. PRIMARY REQUIREMENTS FOR SUCCESSFUL
OCCLUSAL THERAPY
----stable TMJ
----non interfering post.teeth
----anterior teeth in harmony with envelope of function
MASTICATORY MUSCLE FUNCTION IS
AFFECTED BY THE OTHER 3 STRUCTURES.

107. •OCCLUSAL INTERFERENCES
require
•DISPLACEMENT OF TMJ (to
achieve max.intercuspation)&
•Cause INCORDINATION OF
MASTICATORY MUSCULATURE
OCCLUSO MUSCLE PAIN

108. Occlusaldysharmony, most common cause of TMD PAIN in
patients seeking prosthetic rehabilitation
High points or deflective tooth inclines
Muscle hyperactivity
Pain

110. A PERMISSIVE (SMOOTH) ANTERIOR SPLINT SEPARATES THE INTERFERING
MOLAR FROM CONTACT, THUS PERMITTING THE CONDYLE DISK ASSEMBLIES TO
SEAT UP INTO CENTRIC RELATION. THIS ELIMINATES THE TRIGGER FOR MUSCLE ACTIVITY
AND ALLOWS THE INFERIOR LATERAL PTERYGOID MUSCLE TO RELEASE. PEACEFUL,
COMFORTABLE MUSCLE ACTIVITY RESUMES QUICKLY.

111. Posterior occlusal interference: When any posterior tooth
interferes with the anterior guidance in eccentric movement, the lateral
pterygoid muscles are activated and the elevator muscles are hyperactivated.
This results in incoordinated muscle hyperfunction. It also puts the
posterior teeth in jeopardy of horizontal overload, and subjects them to excessive
attritional wear, fractures, and hypermobility.

112. CENTRIC RELATION & TMJ
CENTRIC RELATION IS THE RELATIONSHIP OF THE MANDIBLE TO
THE MAXILLA WHEN THE PROPERLY ALIGNED CONDYLE-
DISK ASSEMBLIES ARE IN THE MOST SUPERIOR POSITION
AGAINST THE EMINENTIAE IRRESPECTIVE OF VERTICAL
DIMENSION OR TOOTH POSITION
GPT 8

113. HOW MANDIBLE GOES INTO CENTRIC
RELATION
TRIAD OF STRONG ELEVATOR MUSCLES
pulls the condyle-disk assemblies up the slippery
posterior slopes of the eminentiae.
The INFERIOR LATERAL PTERYGOID releases and stays
released through complete closure
Complete upward seating of the condyles
CENTRIC RELATION

114. A:SUPERFICIALMASSETER
pulls the condyle against the
posterior slope and up. …..
B:TheINTERNAL
PTERYGOID
PULLTHE CONDYLES UP
from the lingual side of the
mandible. …..
C:TheDEEPFIBERS OF
THE MASSETER PULL
THE CONDYLE UP…..
D:TheTEMPORALISattach to
the coronoid process between
the teeth and theTMJs and
PULLTHE CONDYLE
UP……

115. RELEASE OF INFERIOR
LATERAL PTERYGOID

116. MOST COMMONLY ENCOUNTERED
SIGNS ND SYMPTOMS AFFECTING
TMJ INAPROSTHETIC SET UP
JOINT SOUNDS
JOINT RESTRICTIONS
OCCLUSAL DISCREPENCIES
DYSHARMONY BETWEEN CENTRIC RELATION & OCCLUSION
BRUXISM
EMOTIONAL STRESS (MOSTLY IN EDENTULOUS PATIENTS)

117. A BRIEF ABOUT OCCLUSAL
SPLINTS

118. OCCLUSAL SPLINTS
 An occlusal splint is a removal device
made of hard acrylic creating precise
occlusal contact with the teeth of the
opposing arch.

119.  Temporarily provide an orthopedically
musculoskeletal stable joint position.
 Used to introduce an optimum occlusal
condition that recognizes the
neuromuscular reflex activity.
 Used to protect teeth from excessive tooth
wear.
USES OF OCCLUSAL SPLINTS

120. Types Of Occlusal Appliances
 The two most commonly used are:
1. The stabilization appliance
2. The anterior positioning appliance

121. INDICATIONS
 Stabilization appliance are generally used
to treat muscle pain disorders.
 Anterior positioning appliance are used for
treatment of disc derangement disorders.

122. Bruxism is the most common reason for
making a splint .

123. Considerations before making a splint
 Counseling, behavioral therapy,
relaxation training etc. may work as
well or even better than a splint.
 Age dependant wear is natural and
does not require splint protection.
 Physiotherapeutic exercise can also
sometimes treat the disorder.

124. A maxillary Occlusal Splint is the type
used .

125.  An impression is
recorded and a cast
is prepared.
 This is followed by
adaptation of a 2mm
thick hard clear
sheet of resin with
ultravac pressure
adapter.
Fabrication of Splint

128.  The patient is instructed how to proper
seat the appliance and the final seating is
done by biting.
 Patient is instructed to wear it as per
disorder like in night for bruxism and in
day time for disc problems.
INSTRUCTIONS

129.  A splint should be checked at least once during
the first 10 days after delivery. If adjustments are
needed and performed a new visit within 1-2
weeks has to be scheduled.
 Patients with TMD should preferably be recalled
after 2-6 months. Other splint patients need to be
seen 1-2 times per year.
 At the recall visit you should consider if the
patient may cease using a splint.
Important points in splint management

130. REFERENCES..
1. Gray’s Anatomy
2. Fundamentals of occlusion and TMJ disorders
-- Okeson
3. Grant’s Atlas of Human Anatomy
4. Occlusion – Ash RamfJord
5. Functional occlusion by dawson
6. Joseph H. Kronman et al (ajodo 1994;105:257-64.)
7. Stavros Kiliaridis et al ,European Journal of
Orthodontics 25 (2003) 259–263

131. HUMOR

133. THANK
YOU