3. Temporomandibular joint is the articulation of mandibular condyle in to
mandibular fossa of the temporal bone just anterior to the tragus of the ear.
It can be felt by pressing the immediately anterior to the tragus while opening
and closing the mouth.
6. DISEASES OF TMJ
Developmental disturbances:-
1.Hypoplasia or aplasia of the condyle
(a)Congenital or primary
(b)Acquired or secondary
2.Condylar hyperplasia
3.Bifid condyle
7. Condylar hypoplasia/Aplasia
◦ Condylar aplasia it is the failure of development of the mandibular
condyle, while condylar hypoplasia refers to underdevelopment of the
condyle.
◦ Both aplasia and hypoplasia may be either congenital or acquired and
may involve one side (unilateral) both side(bilateral)
Congenital or primary condylar hypoplasia or aplasia
◦ It is characterized by unilateral or bilateral under development or failure
of the development of the condyle,Usually due to disturbance in the first
and second brachial arches during development.
8. Conditions that show congenital hypoplasia
o Treacher Collins Syndrome
o Oculo auriculo vertebral syndrome
o Hemifacial macrosomia
o Pierre Robin Sequence
o Hurler Syndrome
Acquired or secondary condylar hypoplasia
◦ It may be due to trauma, infection of the mandible or middle ear and
therapeutic irradiation, which interferes the normal development of the
condyle and usually involves the affected side.
CLINICAL FEATURES
Frequently associated with other anatomical defects such as defective or
absence of external ear or under developed mandibular ramus or
macrostomia
9. In most of the cases seen as unilaterally, result in a obvious facial
asymmetry.
Mandible shift to the affected side while the patient opens the mouth
and a noticeable midline shift often present.This results from the
retardation of the downward and forward growth of the mandible in the
affected site, as the growth is normal in the unaffected side.
Bilateral condylar hypoplasia results in micrognathaia, often in
association with crowding of the teeth and anterior open bite.
The extend of the clinical features depends on the time of injury,
duration, and severity of the injury.
TREATMENT
Early diagnosis and intervention are important in managing the
occlusion, speech, and other functions. Although the condition is not
necessarily progressive, the resulting disturbance may become worse as
patient nears puberty.
10. ◦ Cartilage or bone transplants have been used to build up the
underdeveloped portion, preceded in some cases by unilateral or
bilateral sliding osteotomy.
11.
12.
13. CONDYLAR HYPERPLASIA
◦ Condylar hyperplasia manifest itself as a rare unilatera; enlargement
of condyle which is often mistaken for tumours such as osteoma or
chondroma.
◦ The cause of condylar hyperplasia is obscure but a mild, chronic
inflammatory process result in a condition analogous proliferative
osteomyletis has been suggested.
◦ Unilateral occurrence also support a local phenomenon.
TYPES
o According to Obewegeser and Makek, condylar hyperplasia is
classified into 3 distinct categories.
Type A
Type B
Type c
o Type A is hemimandibular hyperplasia,m causing asymmetry in the
vertical plane.In this type the growth is unilateral in the vertical
plane, with minimal deviation of the chin.
14. ◦ Type B is hemimandibular hyperplasia, causing asymmetry in the transverse
plane. In this type, the chin is deviated toward the contralateral side with no
vertical asymmetry. The patient may exhibit crossbite.
◦ Type c is a combination of both type A and type B and exhibits hyperplastic
features unilaterally or bilaterally.
CLINICAL FEATURES
Occurs more frequently in females.
Age – Patient of any age may be affected.
Most common 3rd decade of life.
DIAGNOSIS
Combination of clinical and radiographic findings.
Usually exhibit unilateral, slowly progressive elongation of the face with
deviation of the chin away from the affected side.
The enlarged condyle may be clinically evident or often palpated, presenting
a striking radiographic appearance in both coronal and sagittal views.
15. The affected joint may or may not be painful and malocclusion is a usual
sequele of the condition.
TREATMENT
Usually surgical.
Depending on the severity of the hyperplasia, condylactomy,
orthognathic surgery, or a combination of both may be carried out.
16.
17.
18. BIFID CONDYLE
◦ It is a rare condition affecting, less than 1% of the population.
◦ Characterized by presence of groove or depression of varying depth
around the midline of the condylar head.
◦ Depression may be visible on coronal or sagittal oreination. Usually it is
unilateral, although bilateral bifid condyle have been reported.
◦ Reason for bifidity is controversial and two theories have been
proposed.
◦ According to one theory speculates that bifdity may orginate in embryo
where blood supply to the condyle head is limited,
◦ The other theory suggest trauma due to either birth injury of the
condylar head as the cause of bifidity.
◦ Asymptomatic and do not require any treatment
19.
20. TRUAMATIC DISTRUBANCES OF TMJ
1.Dislocation of condyle
2.Ankylosis (hypomobility)
3.Injury of articular disc
4.condylar fracture
21. DISLOCATION OF CONDYLE
◦ 1.anterior dislocation
◦ 2.cranial dislocation
Cranial Dislocation
Condylar head is dislocated posteriorly into the cranial fossa as a result
of trauma, is extremely rare.
Mainly due to road traffic accidents or sports related injuries
Anterior Dislocation
More common than cranial dislocation.
It occurs when the head of the condyle moves anteriorly over the
articular eminencee into such a position that it cannot be return
voluntarily into its normal position.
22. The forward positioning causes myotactic reflex over the temporalis
muscle resulting in muscle spasm .
Anterior dislocation can further be divided into.
a. Luxation
b. Subluxation
LUXATION
It refers to complete dislocation, which cannot be brought back by the
patient (non self reducing)
SUBLUXATION
Subluxation is a partial or incomplete dislocation, which can be reduced
by the patient (self reducing).
Anterior dislocation may occur repeatedly, and condylar reduction may
become easier with successive dislocation.
Repeated anterior dislocation and self reduction is refers to as habitual
or recurrent dislocation
23. CLINICAL FEATURES
Characterized by sudden locking and un immobilization of the jaw when
mouth is opened, and accomaponied by prolonged spasmodic
contraction of the temporal, medial pterygoid and masseter muscles
with protrusion of the jaw.
Patient experiences severe pain of the TMJs, excessive salivation.
Depression of the skin in the pre auricular area.
All activities requiring movement of the mandible, such as eating or
talking become impossible.
The mouth cannot be closed, and the patient frequently become
panicky, especially it is their first experience.
TREATMENT
Reduction of the anterior dislocated condyle is accomplished by using
inducing relaxation of the muscles and the guiding the head of the
condyle under the articular eminence into its normal position by an
inferior and posterior pressure of thumbs in the mandibular molar area.
24. The necessary relaxation can sometimes be brought about only by
means of general anesthaisa or by tiring the masticatory muscles by
cupping the chin in the palm of the hand and applying a posterior and
superior pressure for 5 to 10 mins.
25. ANKYLOSIS
• It is a disorder in which adhesion of joint components takes place by
fibrous or bony union, resulting in loss of function.
• The most frequent causes of ankylosis of the TMJ are traumatic injuries
and local or systemic infections.
• Other causes of ankylosis include systemic diseases such as ankylosing
spondylitis, rheumatoid arthritis, psoriasis, or previous TMJ surgery.
• Bilateral ankylosis is often a result of rheumatoid arthritis.
26. CLASSIFICATION
◦ TMJ ankylosis is classified into two types.
a) intra-articular
b) extra-articular.
• Intra-articular ankylosis-the joint undergoes progressive destruction of
the meniscus with flattening of the mandibular fossa, thickening of the
head of the condyle, and narrowing of the joint space.
• The ankylosis is basically fibrous, although ossification in the scar may
result in a bony union.
• extra-articular ankylosis results in the "splinting" of the TMJ by a fibrous
or bony mass external to the joint proper, as in cases of infection in the
surrounding bone or extensive tissue destruction.
27. Clinical features
◦ Ankylosis of the joint occurs at any age, but most cases occur before the
age of 10 years. Distribution is approximately equal among the genders.
◦ Mouth opening may be normal or restricted to varying degrees
depending on the type of ankylosis.
◦ In complete ankylosis, bony fusion limits the TMJ movements.
◦ There is usually some degree of movement in fibrous ankylosis when
compared to bony ankylosis.
◦ The type and extent of deformity is partially dependent on whether the
ankylosis is unilateral or bilateral. In unilateral ankylosis, the chin is
displaced laterally and backwards on the affected side because of the
failure of development of the mandible on the affected side.
28. ◦ Attempt to open the mouth leads to deviation of the chin toward the
affected side. Bilateral ankylosis results in the underdevelopment of the
lower face, receding chin, and microg-nathia.
Radiographic features
In fibrous ankylosis, the joint space is often limited.
The articulating surfaces of the condyle and the fossa may be irregular
and appear to inter-digitate in a locking fashion.
In bony ankylosis, a bony bridge exists from the condylar head to the
articular fossa.
Treatment
Treatment of TMJ bony ankylosis is surgical.
Early surgical intervention in childhood can reduce the adverse effect on
facial development.
Different surgical procedures, including condylectomy, gap
arthroplasty.interpositional arthroplasty, and joint reconstruction, have
been attempted.
31. OSTEOARTHRITIS(DEGENERATIVE JOINT
DISEASES)
◦ Osteoarthritis is the most common type of arthritis.
◦ It may occur in all persons older than 40 years.
◦ Etiology is unknown.
◦ it is a disease associated with the aging process.
◦ The joints first involved are those which bear the weight of the body and
are thus subjected to continuous stress and strain.
◦ such as the joints of the knees, hips, and spine.
32. Clinical features
Clinical signs and symptoms of osteoarthritis are often remarkably
absent even in the face of severe histologic or radiographic joint
changes.
Since the TMI is not a weight-bearing joint, the changes are insignificant,
though arthropathy may be present in the other joints.
Those changes that do occur may be the result of disturbed balance of
the joints due to loss of teeth or external injury.
Patients with osteoarthritis of other joints may complain of clicking and
snapping in the TM, but pain is not necessarily a feature.
33.
34. RHEUMATOID ARTHRITIS
◦ Rheumatoid arthritis is a chronic disease of unknown etiology which
commonly begins in early adult life.
◦ (35-50 years) and affects women more frequently than men in a ratio of at
least 3:1.
◦ It is an aggressive condition that can damage the joints within 2 years of
time.
◦ The disease is not due to a specific bacterial infection, there is evidence to
indicate that it may be a hypersensitivity reaction to bacterial toxins,
specifically streptococci.
Clinical features.
Rheumatoid arthritis, in its earlystages, may be manifested by slight fever,
weight loss, and fatigability.
The joints affected are often swollen and the patient usually complains of
pain and stiffness.
35. Involvement of the TMJ may occur concomitantly with the other joint lesions or
may arise subsequently.
Radiographically, joints may be irregular, articular surfaces become flat, and
subcortical pseudocysts and osteophytes may be present.
36.
37. Temporomandibular disorder
(TMD)(temporomandibular syndrome)
◦ TMI syndrome or TMD is the most common cause of facial pain after
toothache.
◦ There is no convincing definition for the disease, and there exist
discrepancies concerning the terminology, definition, and treatment
methodologies.
◦ TMD can be classified broadly as TMD secondary to myo-fascial pain
and dysfunction (MPD)) and TMD secondary to true articular disease.
◦ The MPD type forms the majority of the cases and is often associated
with pain without noticeable destructive changes of the TMJ on
radiograph.
◦ It is frequently associated with bruxism and daytime jaw clenching in a
stressed and anxious person.
◦ The etiology of MPD is multifactorial and includes malocclusion, jaw
clenching, bruxism, personality disorders, increased pain sensitivity, and
stress and anxiety.
38. ◦ The principal factors responsible for the clinical manifestations in MPD are
muscular hvperactivity and dvsfunction due to malocclusion of variable
degree and duration.
◦ Disk displacement is the most common.
◦ Other diseases such as degenerative joint disorders, rheumatoid arthritis,
ankylosis, dislocation, infection, neoplasia, and congenital anomalies may
contribute to pain.
Clinical features.
◦ TMD primarily affects young women aged 20-40 years.
◦ The male-to-female ratio is1:4.
◦ The diagnosis of MPD is based on four cardinal signs and symptoms of the
syndrome:
• Pain
• Muscle tenderness
• Clicking or popping noise in the TMJ
• Limitation of the jaw movement.
The pain is usually felt in the periauricular region radiating to the head and
often associated with chewing.
39. ◦ It is usually unilateral in TMD of articular origin (except rheumatic arthritis).
◦ whereas it may be either unilateral or bilateral in MPD and more severe during
periods of stress.
◦ The jaw movement is often restricted to one side or both sides, and at times with
deviation on mouth opening.
◦ Limited jaw opening due to pain or disk displacement may be seen.
◦ Other symptoms are otalgia, neck pain and/or stiffness, shoulder pain, and
dizziness.
Differential diagnosis
Cluster headache
Migraine headache
Postherpetic neuralgia
Temporal/giant cell arteritis
Trigeminal neuralgia
Middle ear infections.
40. Treatment and prognosis
Most TMDs are self-limit-ing and conservative treatment involving self-
care prac-tices, rehabilitation aimed at eliminating muscle spasms, and
restoring correct coordination are all that is required.
NSAIDs may be used on a short-term, regular basis.
Treatment of chronic TMD is often difficult and best managed by a team
approach, consisting of a primary care physician, a dentist, a
physiotherapist, a psychologist, and, in a few cases. a surgeon.
41. Reference
◦ Shafer’s Oral pathology
◦ Textbook of oral &maxillofacial surgery- Balaji
◦ Human anatomy- chaurasia
