This document provides an overview of the temporomandibular joint (TMJ), including its: - Types (synovial, bicondylar, ginglymoarthroidal) - Anatomy (bones, articular disc, ligaments, muscles) - Histology of the articular surfaces - Biomechanics and functions like opening and closing the mouth - Age-related changes like flattening of bones and thinning of tissues

2. By Dr.Shashwati Paul
Dept of Periodontics

3. CONTENTS
Introduction
Types of joints
Joint Characteristics
Evolution and Embryology
Anatomy
Histology of Articular Surfaces
Muscular Component
Ligaments
Blood Supply
Innervation
Lymphatic Drainage
Biomechanics
Age Changes

4. INTRODUCTION
 Joints are areas where two bones are attached
for the purpose of the motion of the body parts.
 Temporomandibular joint is the articulation
between the temporal bone and the mandible. It
is a bilateral diarthroidal, bilateral ginglymoid
joint. (GPT-8)

5. TYPES OF JOINTS
FIBROUS (Synarthroses)
Sutures {fixed joints}
Syndesmoses {slightly movable joints}
Gomphosis {junction between teeth and their socket}
Synchondroses (hyaline cartilage) {primary}
Symphyses (fibro cartilage)(secondary)
SYNOVIAL(Diarthroses)
Uniaxial-Ginglymus (hinge),Trochoid (pivot)
Biaxial - Condyloid,Saddle
Triaxial-Ball and socket
CARTILAGINOUS
(Amphiarthroses)

6. TEMPOROMANDIBULAR JOINT
 Synovial.
 Bicondylar – Bilateral,
unison functioning
 Ginglymoarthroidal –
Hinge type movement
 Compound – More than one
articular surface
 Complex – Presence of
intracapsular disc

7. 6th weekIU - Articular Disc Appearance.
7th week IU
Meckel’s Cartilage extends all the
way from the chin to the base of the
skull.
12th week IU Condylar growth first
appearance
13th week IU The condyle and articular disc have
moved up into contact with the
temporal bone.
22nd week IU Meckel’s cartilage degenerates
31st week IU Meckel’s cartilage transformed to
anterior ligament of malleus and
sphenomandibular ligament.

8. ANATOMY OF THE TMJ
BONY COMPONENTS
 Glenoid fossa
 Condylar head
 Articular eminence
SOFT TISSUE COMPONENTS
 Articular disk
 Joint capsule
 Ligaments

9. ANATOMY OF THE TMJ

10. TMJ
Articulating
Surface of
the
Temporal
bone
Mandibular
Condyle
Joint
Capsule
Articular
Disc

11. TEMPORAL BONE
 The mandibular condyle articulates at the base of the
cranium, with the squamous portion of the temporal
bone.
 This portion is made up of a concave mandibular fossa,
in which condyle is situated, called the articular or
glenoid fossa.

12.  Anterior to the fossa is a convex, bony
prominence called the articular eminence
 Posterior to the mandibular fossa is the
squamotympanic fissure.

13. MANDIBULAR CONDYLE
The mandible possesses two articular surfaces
located on the superior extremity of each of the
bilateral condylar processes

14. The condyle articulates with the cranium around
which the movements occur.
 From the anterior view it has a medial and lateral
projection called poles.
The medial pole is generally more prominent than the
lateral pole.

15. ARTICULAR DISK
 Articular disck is oval in shape.
Composed of dense fibrous connective tissue
Most part of the disk devoid of any blood vessels or
nerve fibers
Extreme periphery of the disc, however, is slightly
innervated
The disc divides the joint into two cavities, upper
joint cavity and lower joint cavity

16. In the sagittal plane, it can be divided into 3
regions according to its thickness:
 Anterior Band (AB)
 Intermediate Zone (IZ)
 Posterior Band (PB)

17. The disc is slightly thicker medially than
laterally
During movement the disc is somewhat
flexible and can adapt to the functional demands
of the articular surfaces.

18. RETRODISCAL TISSUE
Posteriorly, the articular disc is attached to loose
connective tissue.
Disc- superiorly bordered by the superior retrodiscal
lamina, contains lamina of connective tissue and elastic
fibers.
At lower border is inferior retrodiscal lamina, made of
collagen fibers. Attached to condylar facet.

19. ARTICULAR CAPSULE AND SYNOVIAL
MEMBRANE
 Articular capsule surrounds TMJ like a cuff
 2 layers-
 Outer-Fibrous-Capsular ligament
 Inner-Cellular- Synovial membrane
 Synovial membrane lines TMJ Cavity Internally

20. SYNOVIAL FLUID
. Purpose:
1. Acts as a medium for providing metabolic
requirements to these tissues
2. surfaces during function

21. SYNOVIAL FLUID
Synovial fluid brings about lubrication by
two mechanisms:
1. Boundary lubrication (Primary) :
Synovial fluid is forced from border areas to
the articular surfaces when the joint is in
function.
2. Weeping Lubrication:
Occurs due to the ability of the articular
surfaces to absorb a small amount of
lubrication.

22. RELATIONS OF THE TMJ
 LATERALLY:
-Skin, Fasciae
-Parotid Gland
-Temporal Branches of VII nerve
 MEDIALLY:
-Tympanic plate separates tmj
from Internaly- carotid artery, spine of the
sphenoid with upper end of the
sphenomandibular ligament,
auriculotemporal & chorda tympani
nerves, middle meningeal artery.

23. HISTOLOGY OF ARTICULAR SURFACES
Composed of four Layers or Zones
 Articular Zone
 Proliferative Zone
 Cartilaginous Zone
 Calcified Zone

24. MUSCULAR COMPONENT
 Lateral pterygoid
 Origin –
 Upper head arises from the infratemporal
surface of the greater wing of the sphenoid
 Lower head arises from the lateral surface of the
lateral pterygoid plate
 Insertion - The anterior aspect of the neck of the
mandibular condyle and capsule of the TMJ
 Innervation - A branch of the mandibular
division of the trigeminal nerve

25. Upper
head
• chewing
• Anteriorly rotate
the disc on condyle
during closing
movement.
Lower
head
• Anterior ,lateral
and inferior pull
of mandible.
• Opening of the
jaw
• Protuding the
mandible
• Deviating
mandible to
opposite side.
Function

26. Medial pterygoid
• Origin - Deep origin situated on the medial aspect of the
mandibular ramus .
• Insertion - The inferior and posterior aspects of the
medial subsurface of the ramus and angle of the
mandible.
• Innervation - A branch of the mandibular division of the
trigeminal nerve.
• Function - Working bilaterally - assists in mouth
closing. Working unilaterally – deviation of the
mandible toward the opposite side.

27. Temporalis
 Origin - The floor of the temporal fossa and temporal
fascia
• Insertion - On the anterior border of the coronoid
process and anterior border of the ramus of the
mandible
• Innervation - A branch of the mandibular division of the
trigeminal nerve
• Function - assists with mouth closing/side-to-side
grinding of the teeth. Also provides a good deal of
stability to the joint

28. Digastric
 Origin - The posterior belly arises from the mastoid, or
digastric, notch immediately behind the mastoid
process of the temporal bone.
 Insertion - The posterior belly passes downwards and
forwards towards the hyoid bone where it becomes the
intermediate digastric tendon and joins with the
anterior belly.
 Nerve Supply - derived from the digastric branch of the
facial nerve.
 Vasculature - arterial blood supply from the posterior
auricular and occipital arteries.
 Action - The muscle depresses the mandible and can
elevate the hyoid bone. The posterior bellies act in
unison and are particularly active during swallowing and
chewing.

29. Masseter
two-layered quadrilateral shaped muscle.
 Origin-
 The superficial portion arises from the anterior two-thirds of
the lower border of the zygomatic arch
 The deep portion arises from the medial surface of the
zygomatic arch.
 Insertion - On the lateral surface of the coronoid process
of the mandible, upper half of the ramus and angle of
the mandible
 Innervation - A branch of the mandibular division of the
trigeminal nerve
 Function - The major function of the masseter is to
elevate the mandible, thereby occluding the teeth
during mastication.

30. LIGAMENTS OF THE TMJ
FUNCTIONAL LIGAMENTS:
1. Collateral Ligaments
2. Capsular Ligaments
3. Temporomandibular Ligament
 ACCESSORY LIGAMENTS:
1. Sphenomandibular Ligament
2. Stylomandibular Ligament

31. COLLATERAL LIGAMENTS
Attach Medial and Lateral
borders of articular disc
to poles of the condyle.
They divide joint
mediolaterally into
superior and inferior joint
cavities.
 Responsible for the
Hinge like movement of
the TMJ.

32. CAPSULAR LIGAMENT
 Fibers attached superiorly to temporal bone
along borders of articular surfaces of
mandibular fossa and articular eminence
 Inferiorly attached to neck of the condyle.
 Resist medial, lateral or inferior forces that tend
to separate or dislocate the articular surfaces
and retain synovial fluid.
 Well Innervated
 Provide proprioceptive feedback.

33. TEMPOROMANDIBULAR LIGAMENT
 Composed of two parts:
1. Outer Oblique Portion
2. Inner Horizontal
Portion

34.  Outer Oblique Portion extends from the outer
surface of the articular eminence and zygomatic
process posteroinferiorly to the outer surface of
the condylar neck.
 Inner Horizontal Portion extends from the
outer surface of the articular eminence and
zygomatic process posteriorly and horizontally
to the lateral pole of condyle and posterior part
of articular disc.
 TM Ligament limits rotational movement
 Inner Horizontal portion of the TM Ligament
limits posterior movement of the condyle and
disc.

35. SPHENOMANDIBULAR
LIGAMENT:
Arises from spine of sphenoid bone,
extends downward to lingual
STYLOMANDIBULAR LIGAMENT:
Arises from styloid process, extends
downward and forward to angle and
posterior border of angle of ramus of
mandible.

36. BLOOD SUPPLY
 Internal Maxillary Artery
 Deep Temporal Artery
 Masseteric Artery
 Superficial Temporal Artery
 Transverse Facial Artery
Others:
Deep Auricular Artery
Anterior Tympanic Artery
Middle Meningeal Artery

37. INNERVATION
 Auriculotemporal Nerve
 Deep Temporal Nerve
 Masseteric Nerve
 Four Types of Nerve Endings:
Ruffini Endings (limited to capsule)
Pacini Corpuscles ( limited to capsule)
Golgi Tendon Organ (confined to ligament)
Free Nerve Endings (Most abundant)

38. PROPRIOCEPTION
 Ruffini Endings
Position the mandible
 Pacinion Receptors
Accelerate movement during reflexes
 Golgi tendon Organs
Protection of ligaments Around TMJ
 Free Nerve Endings
Pain receptors

39. Ruffini Posture
proprioception
Dynamic and
static balance
Pacini Dynamic
mechanorecepti
on
Movement
accelarator
Golgi Static
mechanorecepti
on
Protection
(ligaments)
Free Pain
(nociception)
Protection
(joint)

40. LYMPHATIC DRAINAGE
 Described by Tanasesco(1912)
Preauricular Nodes
Parotid Nodes
Submandibular Nodes

41. NEUROPHYSIOLOGY
Golgi tendon
organs and
muscle
spindle
monitor
active muscle
contraction.
Joints
movement and
tendon’s
stimulate the
pacinian
corpuscle. All
receptors
continuously
provide input to
CNS.

42. BIOMECHANICS OF TMJ
Biomechanics of TMJ is a complex
combination activity
Both left and right joints must function
together in co-ordination with jaw movement

43. BIOMECHANICS OF TMJ
The TMJ is a compound joint. It can be divided into
two distinct systems :
One joint system is the tissues that surround the
inferior synovial cavity. Disc is tightly bound to the
condyle by the lateral and medial discal ligaments.

44. BIOMECHANICS OF TMJ
 The second system is made up of the condyle-
disc complex functioning against the surface of
the mandibular fossa. Because the disc is not
tightly attached to the articular fossa, free
sliding movement is possible between these
surfaces in the superior cavity.
 This movement occurs when the mandible is
moved forward (referred to as translation).
Translation occurs in this superior joint cavity
between the superior surface of the articular
disc and the mandibular fossa

45. TMJ IN FUNCTION

46. TMJ IN FUNCTION
 Functional elements
 Glenoid fossa; Posterior surface of articular eminence.
 Entire superior surface of Condylar head.
 Capsule and ligament.
 Articular disc
 Non functional elements
 Glenoid fossa; posterior half

47. Lateral and medial pterygoid
Temporalis,digastric,geniohyoid
Temporalis,masseter,medial
pterygoid

48. Lateral
pterygoid,digastric,geniohy
oid,mylohyoid
Medial and lateral
pterygoid

49. THE OPENING AND CLOSING MOVEMENTS
When the mouth opens the mandibular condyles rotate on a common
horizontal axis and also glide forward and downwards on the inferior
surface of their articular discs.
The discs slide in the same direction on the temporal bones due to their
attachment to the mandibular heads and to contraction of the lateral
pterygoid drawing heads and discs on the articular tubercles.
Discal sliding ceases when their posterior fibro-elastic attachments to the
temporal bones are stretched to their limits.Further hinging and gliding
of the condyles bring them into articulation with the most anterior parts
of the discs when the mouth opens fully

50. In closure movements are reversed.
Each head glides back and hinges on its disc ,still held by the
lateral pterygoid which relaxes to allow the disc to glide back
and up into the mandibular fossa

53. AGE CHANGES
 Stop growing at 20 years of age - continuous
adaptational responses.
 Condylar head –
 Decrease in convexity
 Decrease in condylar height
 Resorption more on lateral aspect than medial
 In extreme cases, drastic changes may produce
disappearance of condyle

54. Glenoid fossa and articular eminence -
 Flattening of the articular fossa.
 Decrease in articular eminence.
 Decrease in the vertical dimension of the
glenoid fossa
 Flattening of the sigmoid curve.

56. CONDYLE
 Becomes more flattened
 Fibrous capsule becomes thicker
 Osteoporosis of underlying Bone
 Thinning or absence of cartilaginous Zone
DISK
 Becomes thinner
 Shows hyalinization along with chondroid changes

57. AGE CHANGES OF TMJ
SYNOVIAL FOLD
 Becomes fibrotic with thick basement
membrane
BLOOD VESSELS & NERVES
 Walls of blood vessels are thickened
 Nerves decrease in number

58. AGE CHANGES OF TMJ
CHANGES LEAD TO :
 Decrease in synovial fluid formation
 Impairment of motion due to decrease in
the disc and capsule extensibility
 Decrease the resilience during mastication
due to chondroid changes in collagenous
elements
 Joint dysfunction in older people

59. TMJ EXAMINATION
• Examined both
clinically and
radiographically.
• Any signs and
symptoms
associated with
pain and
dysfunctions are
noted.

60. PALPATION OF TMJ
Pain or tenderness of TMJ is determined by
digital palpation when the mandible is in
stationary and dynamic movements.
The examiner finger tips are placed over the
lateral aspect of joint areas simultaneously on
both sides.

61. LATERAL PALPATION:
• The finger tips should feel the lateral poles of
condyles passing down towards across articular
eminence. Once position is verified, the medial
force is applied to the joint area to check for any
pain.
POSTERIOR PALPATION:
• Position the little finger in the external auditory
meatus and palpate the posterior surface of
condyle during opening and closing of the
mandible. Palpation is done in such a way that
the condyle displaces the little finger when in the
full occlusion

62. AUSCULTATION OF THE TMJ
Sounds made by the TMJ can be examined
with a stethoscope. Also the timing of
clicking during opening and closure can be
noted.
CREPITATION
This is a grating or scalping noise that occurs
on jaw movements. Sounds like when sand
paper is rubbed against a surface.
Crepitation is very uncommon in
asymptomatic joint and may be an early sign
of degenerative joint disease.
Crepitus is caused by roughened, irregular
anterior surface

63. CLICKING
It occurs due to the uncoordinated movement of condylar
head and TMJ disc. Joint clicking is differentiated as:
Initial clicking: it is a sign of retruded condyle.
Intermediate clicking: it is a sign of uneven condyle surfaces
and articular disc.
Terminal clicking: it is an effect of the condyle being moved
too far anteriorly in relation to the disc on maximum jaw
opening.
Reciprocal clicking: it is an expression of incordination
between displacement of the condyle and the disc.

64. TMJ IMAGING
Diagnostic imaging should be considered for
patients with:
• a history of trauma
• significant dysfunction
• alteration in range of motion
• significant change in occlusion.
Purpose :
• to evaluate the integrity & relationship of hard
& soft tissues
• confirm extent & stage of progression of diseases
• evaluate effects of treatment

65. HARD TISSUE
•Panoramic imaging
•Specialized TMJ radiography
techniques:
Trans cranial
Trans pharyngeal
Trans orbital
•Submento vertex (basal) projection
•Conventional Tomography
•Computerized Tomography
SOFT TISSUE
• Arthrography
• CT scan
• MRI

66. TEMPOROMANDIBULAR JOINT
DISORDERS

67. 1. Intra-articular origin or intrinsic disorders.
2. Extra-articular origin or extrinsic disorders.
Intrinsic factors relate to those conditions
existing within the confines of the capsule of
the joint'.
Extrinsic factors are those not directly associated
with the TMJ

68.  TRAUMA
 Dislocation, subluxation
 Haemarthrosis
 Intracapsular fracture, extracapsular fracture

 INTERNAL DISC DISPLACEMENT
 Anterior disc displacement with reduction
 Anterior disc displacement without reduction

 ARTHRITIS
 Osteoarthrosis (degenerative arthritis, osteoarthritis)
 Rheumatoid arthritis
 Juvenile rheumatoid arthritis
 Infectious arthritis

69.  DEVELOPMENTAL DEFECTS
 Condylar agenesis or aplasia—unilateral
/bilateral
 Bifid condyle
 Condylar hypoplasia
 Condylar hyperplasia
 ANKYLOSIS
 NEOPLASMS
 Benign tumours: osteoma, osteochondroma
 Malignant tumours: Chondrosarcoma,
fibrosarcoma, synovial sarcoma.

70. During normal or unstrained opening of the mouth, the condylar
heads translate forward to a position under the apices of the
articular eminences.
If oral opening proceeds to its maximum capacity, the condylar
heads move to the anterior slope of the articular eminences in many
normal individuals. Excursion of the condylar heads beyond these
limits may be viewed as abnormal and termed as dislocation.
The dislocation can be unilateral or bilateral.
Anterior mandibular dislocation can be classified as
1. Acute
2. Chronic recurrent (habitual) subluxation
3. Long-standing.
The term luxation is also used for acute dislocation and the terms,
subluxation or hypermobility or habitual chronic recurrent
dislocation is substituted for the term dislocation, when it is
incomplete.

71. Extrinsic or iatrogenic causes: Acute dislocation is
common
Blow on the chin, while mouth is open;
Injudicious use of mouth gag during general anesthesia
excessive pressure on the mandible, during dental
extraction
Post-traumatic
Intrinsic or self induced forces as excessive: yawning,
vomiting, singing loudly, blowing wind instruments,
laughing loudly or opening mouth too wide for eating or
hysterical fits can also bring about episode of acute
dislocation.

72.  UNILATERAL ACUTE
DISLOCATION
 BILATERAL ACUTE
DISLOCATION
Unilateral acute dislocation: It
is characterized by difficulty in
mastication and swallowing.
Speaking may be difficult and
profuse drooling of saliva can
be present in the early stages.
A deviation of the chin toward
contra-lateral side is seen.
The deviation produces a lateral
cross and open bite on the
contralateral side.
It is associated with pain, inability
to close the mouth, tense
masticatory muscles, difficulty in
speech, excessive salivation,
protruding chin.
The mandible is postured forward
and movements are restricted.
There is a gagging of the molar
teeth with the presence of anterior
open bite. Difficulty in swallowing
and drooling of saliva is seen.

73. The major problem in reduction of dislocation is
overcoming the resistance of the severe muscle spasm.
Therefore, initially attention is given to reduce tension,
anxiety and muscle spasm.
This can be achieved by
(i) reassuring the patient,
(ii) tranquilizer or sedative drugs,
(iii) pressure and massage to the area, and
(iv) manipulation

74. • First of all, the patient should be given assurance about
the procedure and asked to relax completely in a dental
chair.
• Few drops of local anaesthetic solution may be injected in
the glenoid fossa which will eliminate the pain.
• The operator has to stand in front of the patient and he
has to grasp the mandible with both the hands, one on
each side to reverse the process of dislocation.
• The thumbs of the operator should be covered with gauze
to prevent injury during manipulation, as sudden
reduction can take place trapping the thumbs of the
operator by the teeth

75. MANIPULATION PROCEDURE
The thumbs are placed on the occlusal surfaces of the
lower molars and fingertips are placed below the chin.
Operator has to exert full body pressure and give
downward pressure on the posterior teeth to depress the
jaw and at the same time the fingertips are placed below
the chin to elevate it by giving upward pressure.
The downward pressure overcomes spasm of the
muscles, plus it brings the locked condylar head below
the level of articular eminence and then the backward
pressure is given to push the entire mandible posteriorly

76. This will allow the condylar head to go back into its original
position. After this reduction procedure, the mouth is closed
and patient is asked to keep the oral opening restricted.
Immobilization can be carried out, by giving barrel bandage to
the patient for the period of 10 to 14 days and patient is kept on
semisolid diet. This will allow to give rest to the joint.
Anti-inflammatory, analgesic drugs should be prescribed for
the period of 3 to 5 days

77. Long-standing acute dislocation, which does not respond
to the above procedure can be reduced by administering
general anaesthesia. If manual reduction fails, then open
surgical procedure.
Open reduction consists of opening the joint through
preauricular incision and direct vision manipulation can
be done.
If this also fails then eminectomy or condylectomy
procedure

78. CHRONIC RECURRENT OR
HABITUAL DISLOCATION OR
SUBLUXATION
The term should be reserved for repeated episodes of
dislocation, where there is abnormal anterior excursion of
the condyles beyond the articular eminence, but the
patient is able to manipulate it back into normal position.
So here the condylar head moves, unassisted, forward and
backward over the articular eminence.
This recurrent, incomplete, self-reducing, habitual
dislocation is termed as hypermobility or chronic
subluxation of the TMJ

79. The triad of ligamentous and capsular flaccidity, eminential
erosion and flattening and trauma is well-recognized in the
genesis of chronic recurrent subluxation.
In such predisposed individuals yawning, vomiting,
laughing may precipitate subluxation. It is also seen in
severe epilepsy, dystrophic myotonia and the Ehlers-Danlos
syndrome.
It can be also seen in professionals like teachers, speakers
and musicians

80. Intermaxillary fixation or limiting the oral opening by
giving elastics
Use of sclerosing solution injections into joint space
CAPSULE TIGHTENING PROCEDURES
Capsulorrahaphy — consists of shortening the capsule by
removing a section and suturing it to make it tight.
Placement Of vertical incision in the capsule and then
drawing it tight by overlapping the edges and suturing.
Reinforcement of the joint capsule by turning down a strip
of temporal fascia and suturing to the capsule

81. CREATING OF A MECHANICAL OBSTACLE
A number of procedures have been suggested forcreating
an obstacle, in the region of articular eminence, so that it
can effectively block the excessive anterior excursion of
the condyle.
Lindermann performed an osteotomy on the eminence
and turned it down in front of the condylar head to
prevent its forward movement.
Mayor advocated a placement of graft (taken front the
zygoma)over eminence to increase the size and height.
Placement of silastic block or vitallium mesh implants to
add the height of eminence.

82. DIRECT RESTRAIN OF CONDYLE
Procedures directed towards restraining the condyle
from abnormal forward movements, have been
attempted for over half a century.
Temporalis fascia turned down and sutured to the
lateral surface of the articular capsule.
Piece of fascia lata threaded through a hole in the
zygomatic-arch and second hole in the condyle.
• The fascia was then tightened, until half of the
preoperative opening existed

83. ANKYLOSIS OF TMJ
Ankylosis is a Greek terminology meaning 'stiff joint'. Here
because of immobility of the joint, the jaw function gets affected.
Hypomobility to immobility of the joint can lead to inability to
open the mouth from partial to complete.
The incidence of intra-articular TMJ ankylosis is difficult to
assess. But, in the western literature it is reported as decreasing,
due to better understanding of management of condylar fractures
and also to the decreased incidence of middle ear infection
following the introduction of antibiotics.
While in India the incidence of TMJ ankylosis is still high. The
reported age distribution ranges from 2 to 63 years. Onset is
usually seen before the age of 10.

84. 1. False ankylosis or true ankylosis.
2. Extra-articular or intro-articular.
3. Fibrous or bony.
4. Unilateral or bilateral.
5. Partial or complete.
Extra-articular and intra-articular types of TMI ankylosis
have been described depending mainly on the anatomic
site of the fusion or union. intra-articular ankylosis
indicates union between the articular surfaces of the TMJ,
while extra-articular ankylosis results from lesions
involving extra-articular structures.
The fusion or union of the articular surfaces of the head of
the condyle with the glenoid fossa may be of fibrous or
bony depending on the nature of the tissue.

85. Clinical manifestations vary according to:
(a) severity of ankylosis,
(b) time of onset of ankylosis, and
(c) duration.
1. Early joint involvement-less than 15 years: Severe facial
deformity and loss of function.
2. Later joint involvement -after the age of 15 years: Facial
deformity marginal or nil. But, functional loss is severe.

86. Seen in a child or in a person where the onset was usually in
the childhood.
1. Obvious facial asymmetry.
2. Deviation of the mandible and chin on the affected side.
3. The chin is receded with hypoplastic mandible on the
affected side.
4. Roundness and fullness of the face on the affected side.
5. The appearance of the flatness and elongation on the
unaffected side.
6. The lower border of the mandible on the affected side
has a concavity that ends in a well-defined ante-gonial
notch.
7. In unilateral ankylosis some amount of oral opening may
be possible. Interincisal opening will vary depending on
whether it is fibrous or bony ankylosis.
8. Cross bite may be seen.

87. 1. Inability to open the mouth progresses by gradual decrease
in interincisal opening. The mandible is symmetrical but
micrognathic. The patient develops typical 'bird face'
deformity with receding chin.
2. The neck chin angle may be reduced or almost completely
absent.
3. Antegonial notch is well-defined bilaterally.
4. Class II malocclusion can be noticed.
5. Upper incisors are often protrusive with anterior open bite.
Maxilla may be narrow.
6. Oral opening will be less than 5 mm or many times there
is nil oral opening.
7. Multiple carious teeth with bad periodontal health can be
seen.
8. Severe malocclusion, crowding can be seen and many
impacted teeth may be found on the X-rays

88. The treatment of TMJ ankylosis is always surgical. Early
surgical correction of the ankylosed joint is highly desirable,
if satisfactory function is to be regained.
Surgical strategy adopted depends on the following:
a. Age of onset of ankylosis.
b. Extent of ankylosis.
c. Whether there is unilateral or bilateral involvement.
d. Associated facial deformity

89. SURGICAL TECHNIQUES
Numbers of techniques have been advocated by different surgeons. Critical
analysis of all, filters only to three basic methods.
CONDYLECTOMY is advocated in case of fibrous ankylosis, where the joint
space is obliterated with the deposition of fibrous bands, but there is not
much deformity of the condylar head.
GAP ARTHROPLASTY:
In the extensive bony ankylosis, a broad, thick area of bone deposition
obliterates the entire joint, sigmoid notch and coronoid process.
Identification of the previous joint structure is impossible and mobilization at
the level of the joint becomes difficult, if not impossible (one cannot identify
the roof of the glenoid fossa which forms the floor of the middle cranial
fossa).

90. The term gap arthroplasty is therefore, used to describe the
operation in which the level of section is below that of the
previous joint space and in which, no substance is
interposed between the two cut bony surfaces.
INTERPOSITIONAL ARTHROPLASTY
Interpositional arthroplasty involves the creation of a gap,
but in addition a barrier (autogenous or alloplastic) is
inserted between the cut bony surfaces to minimize the
risk of recurrence and to maintain the vertical height of the
ramus.

91. MPDS is a pain disorder, in which unilateral pain is
referred from the trigger points in myofacial structures,
to the muscles of the head and neck.
Pain is constant, dull ache in contrast to the sudden
sharp, shooting, intermittent pain of neuralgias (chronic
pain). But the pain may range from mild to intolerable.
ETIOLOGY:
Multi factorial origin.
a. Psychologic or Central etiology
b. Occlusal or peripheral etiology
c. Due to intrinsic joint disorder etiology

92. Psychologic or Central etiology:
Emotional stress patient – the selected muscles exhibits general
and sustained hyperfunction, susceptibility to neurotic muscular
contraction resulting in muscle fatigue.
Oral habits – Teeth clenching, bruxism, jaw thrusting, tongue
thrusting, constant
chewing of tobacco, lip licking etc.
Occlusal disharmony:
Inherent malocclusion- is due to developmental deformities. Gross
occlusal discrepancy can lead towards the TMI disorder due to
constant microtrauma.
Acquired malocclusion - failure to replace the lost teeth and mesial
drifting of adjacent teeth leading to occlusal disharmony.
Iatrogenic occlusal disharmony - faulty restoration, high points,
and altered vertical dimension in denture wearer

93. Cardinal symptoms of MPDS are
1. Pain or discomfort (unexplained nature, anywhere
about the head and neck).
2. Deviation and limitation of motion of the Jaw.
3. Joint noises - grating, clicking etc.
4. Tenderness to palpation of the muscles of
mastication - negative recent history of trauma,
infection, ear / joint or maxillary sinus pathosis.
No evidence of any biochemical and/or radiological
feature.
Pain – constant, dull range from mild to intolerable

94. PATIENT COUNSELLING AND ASSURANCE
SYMPTOMATIC PAIN RELIEF
a. NSAIDs for 14-21 days
b. Muscle relaxants only for short term.
i. Diazepam — 2.5 mg. for 10 days
ii. Cyclobenzopine — 10 mg at bed time — 10 days
iii. Meprobamate — 400 mg TID for 7 days
c. Ethyl chloride spray or IM local anesthetic injection into
affected muscles.

95. a. HEAT APPLICATION: 15-20 mins - 4 times per day. It increases
blood flow, acts as sedative, lower muscle tension.
b. ULTRA SOUND: Using ultrasonic waves produces heat deep in
tissues. 0.7 to 1 Watt /cm2 for ten minutes every alternative day.
c. CRYOTHERAPY: Ice pack application to the painful areas 4 times
per day for 20 minutes. Cold compression lowers thermal gradient in
the skin, Interrupting massive concentration of histamine, Lower
pain threshold.
e. MASSAGE WITH COUNTER IRRITANTS
f. USE OF VAPOCOOLENT SPRAY
Fluromethane are ethyl chloride spray-5 seconds
Muscles are gently stretched after that

96. g. ELECROGALVANIC STIMULATION: pulse at 80 cycles per
seconds for ten minutes followed by exercise for 5 minutes. This
delivers a wide range of intensity(voltage) to activate injuried
muscles, stimulate local circulation, achieves excitability and
conductivity without painful healing.
h. TRANSCUTANEOUS ELECTRONIC NERVE STIMULATION
(TENS): it interferes with the sensation of pain in the brain and
increase blood flow to the site.
i. ACTIVE STRETCH EXERCISE: opening and closing of mouth
for ten times.

97. 4. STRESS MANAGERS - to relieve stress by Biofeedback techniques,
Acupressure, Acupuncture, Yoga, Hypnosis, deep breathing relaxation
etc.
5. OCCLUSAL SPLINTS:
To temporarily disengage the teeth
To reduce spasm, contracture and hyperactivity of muscles
To restore vertical dimension
Serves as safety/protective appliances
6. INTRA ARTICULAR INJECTIONS: not indicated for routine
therapy.Hydrocortisone + Lignocaine — 2% (0.5cc) - To treat
inflammation.

98. ANOMALIES OF THE MANDIBLE AND THE TMJ
Hypoplasia
Hyperplasia
Dysplasia / dysmorphia
Deformation

99. MICROGNATHIA- describes an abnormally small mandible.
Many anomalies have this as one of their features.
Cause: ocurs due to deficiency in the amount of avialable
mesenchyme during the formation; due to earlier destruction
or absence of undifferentited cells.
Deficiency is always bilateral and symmetrical.
Many craniofacial anomalies include hypopalsia; normal but
small manidible;often with an abnormality of TMJ.

100. Hallerman Strieff syndrome, Pierre Robin syndrome &
Treacher Collins syndrome.
HALLERMANN STRIEFF SYNDROME: includes a
number of facial defects involving the eyes, nose, maxilla
and mandible giving a distinct facial apperance.
Features: Small mandible particulary the condyles, and
forward positioning of the condyle out of a poorly
formed fossa is characteristic.
Positioning partly postural to improve airway; regularity
and symmetry of the condition suggests a reduction in
mesenchyme at an early embryonic stage.

101. PIERRE ROBIN SYNDROME
Robin sequence;
Small mandible an essential feature; also one of the causes of associated
cleft palate; more generalised hypoplasia involving facial and masticatory
muscles and maxilla mandible and palate; thus wide spread deficiency of
mesenchyme.
TREACHER COLLINS SYNDROME
dysplastic anomalies of eye, zygomatic arch, temporal bone, ear and
mandible; produces a distinct facial appearance.
Small mandible including condyle; unusual TMj relations; condyle
positioned posteriorly and inferiorly in close relation with the external
auditory canal .
This may be related to the abnormal muscle balance in this condition; or
anomaly of the capsule as an unusual discomalleolar ligament

102. TREACHER COLLINS SYNDROME:
Excessive size of the mandible is termed mandibular
prognathism.
Usual criteria for estimating prognathism is the amount of
anterior protrusion of the chin; length of the mandible form
condyle to symphysis.
Unilateral hyperplasia is limited to the condyle, larger than the
unaffected side.
Another form of unilateral hypertrophy is part of a generalized
hemihypertrophy involving many facial structures and the entire
mandible. TMJ on the affected side is positioned far anterior to
the external auditory canal accounting for midline deviation.

103. DYSMORPHIA
Group of anomalies characterized by partial of complete agenesis or
malformation of parts of the TMJ.
AGNATHIA
Complete or nearly complete absence of the mandible and hyoid
bone with other branchial arch defects . Due to failure of neural
crest cells to enter face.
OROFACIAL DIGITAL SYNDROME( TYPE II)
Includes absence of the symphysis(cleft mandible), cleft of lower lip
and macroglosssia, ODS(type I) less severe form.
Dyspalsias of the TMJ belong to the group of anomalies most
commonly termed HEMIFACIAL MICROSOMIA (ALSO termed
Lateral facial Dysplasias).
Features: Complete agenesis of the TMJ, also affects ramus condyle
muscle of mastication etc.

104. CONCLUSION
The TMJ exhibits mature morphology and attains more than 50% of
mature size upon complete eruption of primary dentition.
After 5 years of the age growth velocity decreases and TMJ is sufficiently
formed at an early age to effect the parafunctional habits.
Bruxism and grinding are also implicated in temporomandibular
disorder. Therefore knowledge about the anatomy and physiology of TMJ
and various disorders affects TMJ and treatment is essential.

105. REFERENCES
Jeffery P. Okesons- TMJ and Occlusion.
Tencate’s Oral histology and Embryology-6th edition
Clinical Periodontology- Carranza 10th edition
Textbook of Oral Surgery-Neelima A.Malik, Balaji
Textbook of Anatomy- Chaurasia

106. THANK YOU !!!