Diseases of temporomandibular joint- Dr Shaju George

1. DR SHAJU GEORGE CHAMMANAM -MDS
DEPT OF FACIOMAXILLARY SURGERY
ROYAL DENTAL COLLEGE CHALISSERY
DISEASES OF TEMPOROMANDIBULAR JOINT

2. INTRODUCTION
 The temporomandibular joint is crucial to the
everyday functioning of modern man. It is
subject to all the diseases and disorders that
can affect other joints, but vast majority of
these problems can be dealt effectively with
reversible nonsurgical methods. However, in
small number of cases surgical procedure is
indicated to eliminate the disease or deformity
and to restore the function and anatomy. One
should be aware of the basic biology of the
joint, sound diagnostic knowledge and also on
the efficacy of alternative treatments in
managing these conditions

3. ANATOMY
 The temporomandibular joint (TMJ),
also known as the craniomandibular joint/
articulation is peculiar to mammals. It is the
articulation between the squamous part of
the temporal bone and the head of the
mandibular condyle. The mandibular
articulation is labeled as a bilateral
diarthroidial or freely movable joint. It is
also considered as complex joint, because
it involves two separate synovial joints
(right and left), in which there is a presence
of intracapsular disc or meniscus and both
the joints have to function in coordination

4. ARTICULATORY SYSTEM
 The articulatory system
comprises of the following:
 A-The TMJ.
 B-The masticatory and
accessory muscles.
 C-The occlusion of the
teeth.
 The function is
governed by sensory and
motor branches of the third
division of the trigeminal
nerve (mandibular nerve)
and a few fibers of the
facial nerve

5.  The occlusion of the
teeth plays an
important role in the
function of the TMJ.
Normally, the greatest
part of the force of
mastication is borne
by the dentition of the
jaws, but in case of
occlusal disharmony,
a great deal of force
can be shifted to the
joint itself.

6. Mandibular (Glenoid) fossa (Cranial component)
Limits : Anteriorly, the articular eminence or tubercule,
and posteriorly, a small conical postglenoid tubercle.
Articular eminence: It is a small prominence on the
zygomatic arch. It is strongly convex anteroposteriorly
and somewhat concave mediolaterally.
Postglenoid tubercle: It separates the articular surface of
the fossa laterally from the tympanic plate. And the
tympanic plate separates the TMJ from the bony part of
the external auditory canal.
Glenoid fossa: It has an anterior articular area formed by
the inferior aspect of temporal squama. Its surface is
smooth, oval and deeply hollow and the bone is very thin
at the depth of the fossa. The fossa is lined by a dense
avascular fibrocartilage.

7. Mandibular Component
 Mandibular condyle:
 The articular part of the mandible is an ovoid
condylar process (head) with narrow mandibular
neck. It is broad laterally and narrower medially.
The mediolateral dimension varies between 13 to 25
mm and anteroposterior width varies between 5.5
to 16mm. The majority of human condyles (58%)
are slightly convex superiorly. Twenty-five per cent
of condyles may be flat superiorly and
approximately 12 per cent are pointed or angular in
shape and 3 per cent are bulbous or rounded in
shape. The two condyles of a patient may be
asymmetric.
 The articular part of the condyle is covered by
fiberocartilaginous tissue and not with hyaline
cartilage, as in most other joints in the human body.

8.  TMJ Capsule
 TMJ capsule is a thin sleeve of fibrous
tissue investing the joint completely. It is a
funnel-shaped capsule, which blends with the
periosteum of the mandibular neck and it
envelops the meniscus. It is attached above
anteriorly to the anterior border of the articular
eminence and posteriorly to the lip of the
squamotympanic fissure and to the anterior
surface of the postglenoid process and also to
the circumference of the cranial articulating
surface and below to the neck of the condyle,
on the lateral as well as on the medial aspect.
Inside this fibrous tissue capsule, there is a
lining of silky synovial membrane.

9.  Ligaments
 Lateral or
Temporomandibular
Ligament
 TMJ capsule is reinforced
by this main stabilizing
ligament. It extends
downward and backward
from the articular eminence
to the external and posterior
side of the condylar neck. It s
posterior fibers are united
with the capsular fibers. This
ligament is composed of
collagenous fibers that have
specific length and poor
ability to stretch, hence it
maintains the integrity and
limits the movement of TMJ.

10.  Accessory Ligaments
 Accessory ligaments
make no contribution to
joint activity.
 Sphenomandibular
ligament: a flat band arising
from the sphenoid spine
and the petrotympanic
fissure, runs downward and
medial to the TMJ capsule
and gets inserted on the
lingual of the mandible.
Sphenomandibular ligament
is important landmark
during surgery, as maxillary
artery and auriculotemporal
nerve lies between it and
the mandibular angle.

11.  Articular Disc or Meniscus
 The TMJ is a diarthroidial synovial paired joint.
This means that there are two joint movements,
which occur in separate compartments of this
synovial joint and that one joint cannot operate
without the other.
 The meniscus or an intervening disc divides
the articular space into two compartments:
 The lower or inferior compartment – condylodiscal
complex between the condyle and the disc.
 The upper (temporodiscal) or superior
compartment between the disc and the temporal
bone or glenoid fossa.
 The disc is biconcave in the sagittal section.
The superior surface in concavoconvex to match
the anatomy of the glenoid fossa and inferior
surface is concave to fit over the condylar head.

12.  The disc blends medially and laterally with the
capsule, which is attached to the medial and
lateral poles of the condyle. Anteriorly, the disc
is attached to the articular eminence above
and to the articular margin of the condyle
below. It is also confluent anteriorly with the
capsule as well as with fascial of the superior
head of the lateral pterygoid muscle.
Posteriorly, the disc is attached to the
posterior wall of the glenoid fossa above and
to the distal aspect of the neck of the condyle
below. This area is called as the posterior
bilaminar zone or retrodiscal tissue which has
a rich neurovascular supply. Sensory branches
of auriculotemporal nerve are abundant here.

13.  Radiographs:
 There is no perfect temporomandibular
radiograph in the diagnosis of
temporomandibular diseases.
 Panaromic radiographs are excellent for
screening, but not good for diagnosing internal
derangement. This can demonstrate changes in
condylar shape, image coronoid process and
look for antegonial notching.
 Transcranial radiographs is of some value in
the diagnosis of internal derangement. As disk
displacement occurs there is superior
positioning of the condyle, which is seen in
radiographs as lack of joint space.

14.  Arthrography
 The arthogram is the gold standard in the
diagnosis of internal derangement. This clearly
demonstrates the phenomena of reciprocal
clicking and locking in both acute and chronic.
Plain films may show a narrow joint space and
some degree of arthritic change but the
arthrogram will show the displacement.
 Arthroscopy
 This is helpful in diagnosing the presence
and degree of disk displacement, which is seen
as anteriorly positioned inflamed retrodiskal
tissue with varying degrees of synovitis.

15. CLASSIFICATION
 The disorders of temporomandibular joint can be classified into
structural and functional disorders:
 Structural disorders:
 1-Developmental
 2-Inflammation
 -Acute
 -Chronic
 3-Infection
 4-Degenerative
 5-Neoplasia
 6-Mobility disorders
 -Hypomobility / ankylosis
 -hypermobility
 7-Trauma
 Functional disorders
 - Pain/ dysfunction syndrome

16.  Hypomobility and hypermobility of the temporomandibular
joint
 Motility disorders of the temporomandibular joint
emanating from either too little or too much movement of the
condyle occur much less frequently than internal
derangement, arthrtidies and other diseases of the synovial
joints. Mobility disorders present stern challenges in the
diagnosis and treatment.
 Hypomobility resulting from ankylosis is an extremely
disabling affliction, causing problems in mastication,
digestion, speech and oral hygiene. Ankylosis occurring in
childhood may grossly affect mandibular growth and result
in gross facial deformity. Hypomobility occurring from either
intraarticular bony or fibrous ankylosis is called true
ankylosis, while those arising from extraarticular causes are
called false ankylosis.
 Hypermobility disorders result from hypertranslation of the
mandibular condyle anterior and superior to the articular
eminence. These disorders are composed of
hypertranslation, subluxation and dislocation.

17.  Hypomobility disorders.
 The treatment of hypomobility disorders is a
clinical challenge. These disorders can be
classified into the following as trismus and
ankylosis.
 Trismus is caused by stiffness of the
masticatory muscles.
 Kazanjian in 1938 classified the ankylosis into true
and false.
 - False ankylosis / Pseudoankylosis results from
pathology outside the joint, resulting in mandibular
hypomobility.
 True ankylosis is caused by fibrous or bony fusion
of intraarticular joint structures.
 The more severe form of hypomobility result from
true bony ankylosis of the condyle to the glenoid
fossa.

18.  Aetiology of hypomobility disorders.
 The cause of hypomobility is varied arising as a result of
 1-Trismus
 a- Odontogenic – myofascial pain, malocclusion.
 b- Infection – masticator space.
 c -Trauma – fracture of the mandible, muscle contusion.
 d -Tumours – nasopharyngeal tumours, tumours that invade
jaw muscles.
 e - Psychological – Hysterical trismus.
 f - Pharmacological – Phenothiazines
 g - Neurologic – Tetanus.
 2- Pseudoankylosis
 a - Depressed zygomatic arch fracture
 b - Fracture dislocation of the condyle.
 c - Adhesions of the coronoid process
 d - Hypertrophy of the coronoid process
 e - Fibrosis of the temporalis muscle
 f - Scar contracture following thermal injury
 g - Tumor of the condyle and coronoid process.

19.  3 -True ankylosis
 A - Trauma
 Intracapsular fracture (children).
 Medial displaced condylar fracture
 Obstretic trauma
 Intracapsular fibrosis
 B - Infection
 Otitis media.
 Suppurative arthritis.
 C --Inflammation
 Rheumatoid arthritis/
 Still’s disease.
 Ankylosing spondilitis.
 Marie-StÛmpell disease.
 Psoriatic arthritis.
 D - Surgical
 Postoperative complication of TMJ surgery &
Orthognathic surgery

20.  Trismus
 The most frequent cause of hypomobility
is muscular trismus. Trismus is derived from
the Greek term meaning “grinding together”
and may be myogenic, neurogenic or
psychogenic origin.
 Trismus is thought to be a protective
reflex that minimises jaw movement to
prevent the spread of bacteria, tumour cells,
or further trauma to already injured tissue.
Trismus id mediated through arthrokinetic
reflex from propioceptive nerve endings in the
periodontium, the muscle spindles and
mechano-receptors situated in the joint
capsule through the brainstem to the muscles
of mastication.

21.  The causes of trismus include:
odontogenic sources like myofacscial
pain, malocclusion etc.; infection around
the masticator facial spaces; trauma with
fracture of mandible; tumour invading the
jaw muscles and contiguous structures;
extrapyramidal reactions secondary to
drugs such as the phenothiazines; and
psychogenic and neurogenic sources
such as hysterical trismus, tetanus toxins
or brain tumours.
 The management of trismus is directed
at the causative factors.

22.  False ankylosis
 Hypomobility as a result of extraarticular
causes of obstruction are called
pseudoankylosis. There is confusing
mention in the literature about false
ankylosis and trismus. Miller et al in 1975
classified false ankylosis into six groups as:
 Myogenic
 Neurogenic
 Psychogenic
 Bone impingement
 Fibrous adhesions
 Tumors

23.  The factors frequently cited as the cause for the
extraarticular obstruction are
 The depressed fracture of the zygomatic arch, which
impinges on the coronoid process result obstruction of
free movement of the mandible.
 Fracture dislocation of the condyle limits mobility, either
as a result of direct trauma to the soft tissues and joint
structures or because the head of the condyle obstructs
movement of the mandible.
 Changes in and around the coronoid process – either
hypertrophy or fibrosis causes hypomobility.
 Fibrosis of temporalis muscle results in hypomobility.
This is seen in temporal shunt procedures carried out
for the correction of hydrocephalus.
 Other causes are fibrosis of the elevator muscles of
mandible as a result of burns or radiation therapy and
dystrophic calcification in myositis ossificans.
 The management of these cases of false ankylosis is
directed towards eliminating the causative factors.

24.  True ankylosis
 The intraarticular cause for ankylosis may range from
fibrous, fibro-osseous, osseous to osteocartilagenous.
The aetiology and pathogenesis are
 1- The most frequent cause for bony ankylosis is
trauma to the joint. In the child the most likely
mechanism of ankylosis is following a blow to the chin
or following obstetric trauma. Rich anastamosis of
capillaries penetrate the articular layer of condylar
cartilage and found lying just under the thin cortex in
the young individuals. The condylar neck is broader in
the children. There is crushing injury to the articular
surfaces following trivial injury. Trauma causes
extravasation of blood resulting in haemarthrosis or
intraarticular comminuted fracture with fragmentation
and haemarthrosis. Subsequent ossification of this
fibroosseous mass ultimately results in ankylosis.
Obstetric trauma is also an etiologic factor in the
development of ankylosis. In the adult ankylosis results
either from a medial displaced fracture of condyle and
bony fusion of the neck of condyle to the zygomatic
arch or from fibrous ankylosis.

25.  2- Intraarticular infection is the second leading
cause for true ankylosis. Before the use of
antibiotics, the incidence of ankylosis resulting
from infection exceeded that caused by trauma.
Infection to the temporomandibular joint can
produce prolonged limitation of motion,
disturbance and destruction of articular surfaces
and alteration of normal physiological process of
temporomandibular joint. Destruction of articular
surfaces along with limitation of motion will lead
to ankylosis.
 3- Ankylosis as a result of inflammatory
arthritidies occurs in less than 7 % of cases.
Rheumatoid arthritis, Still’s disease (juvenile
rheumatoid arthritis), Marie- StÛmpell disease,
psoriatic arthritis and osteoarthritis comprise this
group of disease.

26.  4- Fibrous and bony ankylosis can occur
following TMJ arthroplasty and
mandibular orhognathic procedures.
Adhesions can form between the disk and
the articular eminence following disk
repair procedures. Bony ankylosis can
occur after diskectomy procedures
without proper postoperative
physiotherapy or after multiple surgical
procedures on TMJ.
 5- Rarely, ankylosis may result from
neoplasia- either a tumor of the condyle, a
metastatic lesion, or chondromatosis of
the TMJ.

27.  Diagnosis of ankylosis
 The ankylosis of the
temporomandibular joint has distinct
clinical and radiological features.
 Clinical examination
 The findings depend on the time of
onset, severity, duration and whether the
ankylosis is unilateral or bilateral. The
features seen in the ankylosis occurring
at an early age before the completion of
the growth of mandible are.

28.  1- Restriction of mandibular motion. In severe cases
the mouth opening will be less than 5 mm. In false
and fibrous ankylosis there will be varying degree of
jaw motion, usually less than 15-mm. Unilateral
ankylosis will produce deviation of the mandible to
the ankylosed side on opening. This is due to the
hypermobility of the condyle on the normal side and
an absence of translation on the ankylosed side.
 2- Mandibular deficiency if the ankylosis has
produced severe damage to the joint at an early age.
There will be decreased ramal height, micrognathia
and bird face appearance in cases of bilateral
ankylosis. There is prominent antigonial notch due
to pull of the muscles attached to the mandible. The
facial deformity of the ankylosis is the combined
result of loss of epiphyseal growth and absence of
stimulation from the functional matrix.

29.  3 - Facial asymmetry if the ankylosis is unilateral and
occurs at an early age. There will be micrognathia
with chin deviated to ankylosed side and apparent
deficiency of the body of the mandible region on the
normal side. This is due to normal growth of the
mandible on the normal side when compared to the
ankylosed side. These cases will have associated
feature of canting of occlusion.
 4 - Besides these there will be varying degree of
malocclusion, caries tooth, poor oral hygiene,
halitosis and hypertrophic suprahyoid musculature.
 In case of adults the history is usually of limited
jaw opening and altered mandibular function
developing over a period of time. Facial
morphological characteristics are normal because
the alterations started after completion of growth.

30.  Radiological examination
 Plain film radiographs is of little value. They help in
visualising joint morphologic characteristics as narrowing
of the joint in inflammatory joint disease
 Arthrography may be occasionally useful in demonstrating
fibrous ankylosis but it is contraindicated in bony ankylosis.
 MRI imaging is of little value in the diagnosis of TMJ
ankylosis.
 The panoramic radiographic view is adequate for initial
screening.
 TMJ tomography taken in coronal and sagittal sections
gives more information. They are helpful in localising and
quantifying the bony ankylosis. Tomographic sections
through the entire joint provide information about condyle
and fossa morphologic conditions, joint space integrity and
location of osseous union. They may also reveal large
extraarticular mass of bone attached to the zygomatic arch
laterally and to the base of the skull medially.

31.  Classification of the ankylosis
 Sowhney in 1986 graded TMJ ankylosis into
following types.
 Type I: The condylar head is present without
much distortion.
 Type II: Bony fusion of the misshaped head and
the articular surface. No involvement of the
sigmoid notch and coronoid process.
 Type III: A bony block bridging across the ramus
and the zygomatic arch. Medially an atropic
dislocated fragment of the former head of the
condyle is still found. Elongation of the
coronoid process seen.
 Type IV: The normal anatomy of the TMJ is
totally destroyed by complete bony block
between ramus and skull base.


32.  Management of TMJ ankylosis
 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.
 Age of onset of ankylosis
 Extension of ankylosis
 Weather there is unilateral or bilateral
ankylosis
 Associated facial deformity

33.  Aims and objections of surgery:
 Release of ankylosed mass and creation of a
gap to mobilize the joint.
 Creation of a functional joint
 To improve patient nutrition
 To improve patients oral hygiene
 To carry out necessary dental treatment
 To reconstruct the joint and restore the vertical
height of the ramus.
To prevent recurrence
 To restore normal facial growth pattern (Based
on functional matrix theory)
 To improve esthetics and rehabilitate the
patient.


34.  Surgical treatment
 Number of techniques have been
advocated by different surgeons.
 Critical ankylosis of all filters only to
three basic methods.
 Condylectomy
 Gap arthroplasty
 Interpositional arthroplasty

35.  Surgical considerations in children
 Surgical treatment of ankylosis in
children includes two objectives
 To improve mandibular function or
 To maintain normal growth and
development of the face.

36.  Hypermobility disorders.
 Hypermobility disorders mean excessive
mobility, when applied to temporomandibular
joint it means hypertranslation. In 1832, Sir
Astley Cooper proposed the principles for
diagnosis and treatment of dislocation of the
lower jaw. He introduced the terms complete
dislocation (luxation) and imperfect
dislocation (subluxation).
 Hypermobility can be divided into three
interrelated clinical entities:
 Hypertranslation / hypermobility
 Subluxation and
 Dislocation

37.  Hypertranslation refers to the excessive anterior
movement of the condyle during opening.
Normally the condyle translates to the inferior
aspect of the articular eminence on full opening.
It may be predisposing factor to subluxation,
dislocation or internal derangement. Treatment
is seldom required for hypertranslation.
 Subluxation is defined as the displacement of
the condyle out of glenoid fossa and
anterosuperior to the articular eminence, which
can be reduced by the patient (self-reduced).
Patient might usually complaint of temporary
inability to close the jaw completely. Subluxation
can occur along with internal derangement, here
it occurs when the condyle translates over the
posterior surface of the disk and comes to rest
anterior to it. Treatment is not indicated in the
absence of pain.

38.  Dislocation is similar displacement of the condyle,
which cannot be self-reduced. Dislocation might be
acute or may be recurrent or habitual. The highest
incidence of recurrent dislocation is among females.
 Causes
 The dislocation is caused by
 Dysfunction of TMJ
 Abnormal Glenoid fossa
 Abnormal Condylar head
 Relaxation of ligaments
 Relaxation of capsule
 Dysfunction of muscles of mastication
Acute dislocation is caused by
 Trauma
 Sudden movement as in singing or yawning or as a
result of excessive downward pressure during
extraction

39.  Factors precipitating dislocation can be
grouped into extrinsic and intrinsic factors
 Intrinsic factors:
 Overextension injury
 Yawning
 Vomiting
 Wide biting
 Seizure disorders
 Extrinsic factors:
 Trauma
 Blow to the chin when mouth is wide open
 Manipulation of the jaw during
 Intubation
 Endoscopy
 Tooth extractions

40.  Miscellaneous causes
 Internal derrangement
 Occlusal discrepencies
 Factors modifying dislocation:
 Connective tissue diseases
 Ehlers-Danlos syndrome
 Marfan syndrome
 Psychogenic
 Habitual dislocation
 Parkinson’s disease
 Tardive orofacial dyskenesia
 Drug induced
 Phenothiazines.


41.  Signs and symptoms of acute and chronic
dislocation are the same and include
 1.Inability to close the mouth.
 Preauricular depression of the skin
 Prominence of the condylar head anterior to
the articular eminence.
 Elongated face.
 Excessive salivation
 Tense, spasmodic muscles of mastication
and
 Severe pain of the TMJ.

42.  Acute dislocation will produce damage to
the disk, ligament and capsule. There is an
inflammatory oedema characterised by
swelling, tenderness and increased
temperature.
 In chronic dislocation pain will be
minimum and there won’t be any swelling.
 Radiologic examination is essential to rule
out associated condylar fracture prior to
reduction

43.  Management
 Treatment of mandibular dislocation depends on
time elapsed between occurrence and
treatment. The longer elapsed period indicates a
difficult reduction. In acute cases immediate
reduction should be done and most often it will
be adequate. In chronic and longstanding cases
other forms of surgical treatment are to be
considered.
 Manual reduction will be complicated with
difficulties because of
 Anxiety, apprehension of the patient
 Severe spasm of masseter.

44.  Therefore before attempting reduction the
following measures are to be taken
 Reassure the patient.
 Asking the patient to open the mouth
 Mild sedatives like Diazepam
 Tranquillisers
 Massage over the coronoid and masseter
 Injection of local anaesthetic to the joint,
for disruption of reflex contraction reflex.

45.  Manual reduction
 This is done by standing in front of the
patient. Patient is firmly seated and head
supported. Thumbs wrapped with gauze
and placed over the occlusal surface of
mandibular molar teeth or alveolar ridge.
The lower aspect of chin is grasped with
fingers. Patient is encouraged to relax and
open in the direction of dislocation. The
condyle is depressed by pressing down in
the mandibular molar region and
simultaneously elevation of the anterior
region with fingers will rotate the condyle
over the articular eminence into the fossa.

46.  The difficulty encountered with treating
mandibular dislocation increases with the
duration of dislocation. In long standing cases
the dislocated condyle would have undergone
fibrous adhesions to the disk and articular
eminence. The jaw muscles would also have
undergone fibrotic changes. These prevent
nonsurgical methods of reduction. In such
cases the modalities of management include:
 Manual reduction under general anaesthesia
and muscle relaxant.
 Using functional appliance
 Using class III elastics.
 Surgical methods

47.  Surgical methods
 Open technique. Here wires are hooked
around the sigmoid notch and the condyle
is distracted inferiorly and condyle is
repositioned into the fossa.
 In case of fibrotic temporalis
coronoidectomy aids in repositioning of
the condyle.
 Condylectomy
 Eminectomy
 Sagittal split osteotomy.

48.  Management of chronic recurrent dislocation
 Management of cases with chronic
persistent dislocation is troublesome. These
are ideally managed by surgical methods.
Before initiating surgical intervention, all
reversible etiologic causes should be
investigated and possible psychological factors
evaluated. Many procedures have been devised
to manage this problem
 Surgical procedures for correction recurrent
dislocation can be divided into three types:
 Those that removing the blocking factor in the
path of the condyles
 Those that limit the range of motion
 Those that alter muscle balance.