Temporo-mandibular Joint Disorders

Introduction

Temporomandibular Joint disorders can be grouped under the following conditions:

  • Temporo-Mandibular Joint (TMJ) pain dysfunction syndrome
  • Osteoarthritis
  • Rheumatoid arthritis
  • Trauma.
  • Developmental defects
  • Ankylosis
  • Infection
  • Neoplasia

TMJ pain dysfunction syndrome

The most common problem in or around the TMJ

Clinical features and symptoms of Temporo-mandibular Joint Disorders

  • Equal frequency between genders, but five times as many females seek treatment
  • Patients are usually between 15 and 40 years
  • Unilateral or bilateral dull pain within the TMJ and/or surrounding muscles, sometimes on waking or during eating or speech
  • TMJ may lock in the open or closed positions, occasionally
  • TMJ sounds such as clicking, crunching or grating are often described
  • Associated headache is usually located in the temporal region
  • Pain is cyclical and usually resolves, but may recur
  • May be associated with psychological stress

Differential diagnoses

  • Psychologic depression
  • Migraine

Treatment

Treatment objectives

  • Most symptoms are self-limiting and do not require treatment
  • Treatment should be conservative and reversible

Non-drug treatment

  • Educate patient about the condition, emphasizing its frequency and self-limiting nature
  • Soft diet
  • Apply moist heat to painful muscles
  • Physiotherapy

Drug treatment

Analgesics as appropriate
Anxiolytics

  • Diazepam 5 mg orally 1 hour before sleep, then 2 mg every 12 hours, for up to 10 days (maximum)

Supportive measures

  • Occlusal splints

Osteoarthritis

  • This is rare
  • Increasing incidence after 50 years
  • Joint crepitus denotes degenerative joint disease
  • May be accompanied by pre-auricular pain, but not involving the masticatory muscles
  • Radiographs (e.g. panoramic, trans
    pharyngeal, trans-cranial, oblique, lateral, open and closed) show degenerative joint disease

Rheumatoid arthritis

  • A disease of unknown aetiology
  • Autoimmune mechanisms and immune complex formation have been implicated
  • Usually begins in early adult life and affects females more frequently
  • Patients rarely complain of pain from TMJ but clinical examination shows TMJ involvement in 50% of cases
  • Limitation of mouth opening; softness, crepitus, referred pain, and tenderness on biting
  • Severe disability is unusual

Trauma

Clinical features include:

  • Condyle fracture or trauma arthritis
  • Pain and trismus of traumatic arthritis resolve after one week
  • Micro-trauma from parafunction may result in chronic symptoms
  • Dislocation is usually a result of trauma and is rare; very rarely it occurs after yawning

Developmental defects

  • Aplasia of the condyle is extremely rare and may be unilateral or bilateral
  • Hypoplasia of the condyle may be congenital or acquired
  • Cause of congenital hypoplasia is not known; either one or both condyles may be involved
  • Acquired hypoplasia may be secondary to trauma, infection or radiation
  • Hyperplasia of the mandibular condyle is rare and self-limiting. Cause is unknown. It is
    generally unilateral with resultant facial asymmetry, deviation of mandible to the opposite side and malocclusion

Ankylosis

  • Ankylosis follows trauma, infection or other inflammatory condition
  • A disorder that leads to restriction of mouth opening from partial reduction to complete immobility of the jaw

Clinical features

An extremely disabling affliction that causes problems in mastication, digestion, speech, appearance, and oral hygiene
In growing patients, deformities of the
mandible and maxilla may occur together with malocclusion

Treatment

  • Temporo-mandibular joint (TMJ) ankylosis in children is challenging
  • Surgical correction is technically difficult
  • Incidence of recurrence after treatment is high
  • 7-step protocol consists of:
    1. Aggressive excision of the fibrous and/or bony ankylotic mass
    2. Coronoidectomy on the affected side
    3. Coronoidectomy on the contralateral side, if the above 2 steps do not result in a maximal incisal opening greater than 35 mm or to the point of dislocation of the unaffected TMJ
    4. Lining of the TMJ with a temporalis myofascial flap or the native disc, if it can be salvaged
    5. Reconstruction of the ramus condyle unit with either distraction osteogenesis or costochondral graft and rigid fixation
    6. Early mobilization of the jaw. If distractionosteogenesis is used to reconstruct the ramus condyle unit, mobilization begins the day of the operation. In patients who undergo costochondral graft reconstruction, mobilization begins after 10 days of maxillomandibular fixation.
    7. Finally, all patients receive aggressive physiotherapy
  • Adults may be treated with one or several osteotomies or joint replacement

Neoplasia

Primary neoplasms arising from the
structures of the TMJ are extremely rare.
Benign tumours such as chondromas and
osteomas are more frequent than sarcomas arising from bone or synovial tissues.
Others are secondary carcinomas