Temporomandibular Joint Disorders Short Notes

Question 1. Internal derangement of temporomandi¬bular joint. (or)
Articular disk displace¬ment.
Answer:

• The articular disk is situated between the condyle and glenoid fossa. It has muscle attachment in the front and a connective tissue band at the posterior aspect. These attachments make the disk to move forward and backward in the glenoid fossa when the condyle moves (opening and closing movements).
• Disk displacement (internal derangement) is described as a disturbance in the normal anatomic relationship between the disk and condyle that interferes with the smooth movement of the joint and causes momentary catching, clicking, popping, or locking.

Disk Displacement with Reduction:

• The articular disk is positioned anterior to the condylar head. The disk remains in the anterior position as long as the mouth is closed. When the mouth is opened, the disk is repositioned on the condylar head.
• The movement of the disk against the condylar head may result in a clicking, snapping, or popping sound but jaw movements are not affected.
• When the disk is displaced anteriorly, there is an excess stretch over the methodical tissues by the recurrent forces exerted by the condyle. This tissue has an adaptive capacity to these forces and transforms to a pseudo-disk state.
• In this situation, if the disk is recaptured, it results in complete translational condylar movement and an audible clicking known as disk displacement with reduction. When the condyle is back to the methodical tissue, a closing or reciprocal click will result.

Disk Displacement without Reduction (Closed Lock):

• In this, forward translation of condyle is limited by the anterior position of the disk, allowing only rotational and not translational movement.
• Patients report a sudden onset of pain and inability to open the mouth (mouth opening is restricted to 20-30 mm). The patient may also report the immediate cessation of joint noise with the onset of the symptoms. Clinically, the mandible deviates to the affected side during mouth opening, due to the translational movement of the unaffected joint.

Temporomandi¬bular joint Treatment:

• Stretching exercises
• Occlusal splints
• Arthrocentesis.

Question 2. Describe capsulitis and synovitis.
Answer:

• Inflammation of the capsular ligament is known as capsulitis and presents as constant pain and swelling over the joint. Trauma or abnormal function leading to inflammation is the causative factor.
• Pain is caused by movements that stretch the capsular ligament. Inflammation may increase joint fluid volume, and when this occurs, the condyle is displaced inferiorly resulting in an ipsilateral posterior open bite.
• The synovial membrane clears the debris through its rich vascular supply. Pain mediators are also released at this stage of capsulitis. When this healing response is reduced, the synovial membrane gets inflamed and is known as acute synovitis. Inflammation of the synovial membrane is an early sign of degenerative joint disorder.

Capsulitis and synovitis Treatment:

• Arthrocentesis and arthroscopy for joint lavage and lysis of adhesions will provide a good therapeutic effect.
• These procedures eliminate particulate debris and reduce inflammation. Steroid injections are also used to reduce synovial inflammation and pain.

Question 3. Describe bruxism.
Answer:

• Bruxism is defined by the American Academy of Orofacial Pain as diurnal or nocturnal parafunctional activity including clenching, bracing, gnashing, and grinding of the teeth.
• American sleep disorders association defines bruxism as tooth grinding or clen¬ching during sleep plus one of the following: Tooth wear, sounds or jaw muscle discomfort in the absence of a medical disorder.

Bruxism Etiopathogenesis:

• Daytime bruxism is associated with anxiousness, depression, and stress-related parafunction.
• Abrupt sleep disturbance (arousal response) is associated with repulsive changes like involuntary body movements and bruxism.
• Occlusal interference may cause local exaggerated muscle response and bruxism.

Bruxism Symptoms:

• Facial pain, earache, and headache.
• The International diagnostic grading system for sleep and awake bruxism:
  • Possible: Based on self-report, a questionnaire survey, and clinical history.
  • Probable: Based on self-report and the clinical examination.
  • Definite: Based on the self-report, clinical examination, and polysomnographic record.

Bruxism Treatment:

• No specific treatment is available to stop sleep bruxism. Behavior modification therapy, such as habit reversal therapy, relaxation techniques, and biofeedback, may reduce daytime bruxism.
• The occlusal splints and night guards minimize the adverse effects of bruxism.

Question 4. Temporomandibular joint ankylosis.
Answer: Ankylosis is defined as stiffness of a joint due to fusion of TMJ condyle with base of skull due to abnormal adhesion, and rigidity of the joint space by bone or fibrous tissue.

Etiology of Temporomandibular Joint Ankylosis:

• It may either be congenital or acquired.
• Congenital ankylosis is very rare and obstetric trauma is the cause. Congenital abnormalities like Pierre Robin syndrome and Treacher Collin’s syndrome are also associated with TMJ ankylosis.
• The acquired type of TMJ ankylosis arises from trauma, infection, systemic inflammatory disorders, irradiation, previous surgery, and neoplasm. Post-traumatic TMJ ankylosis follows delayed treatment, inadequate surgery, prolonged immobilization or insufficient physiotherapy.
• Temporomandibular joint (TMJ) ankylosis is either fibrous (pseudo ankylosis) or bony (true ankylosis).
  • True bony ankylosis occurs in children under 10 years of age due to the fusion of the condylar head and the temporal bone. This condition has a preference for children because of the higher osteogenic tendency and incomplete state of disk development. Restricted mandibular movements, deviation of the jaw towards the affected side on opening, and facial asymmetry are the clinical findings.
  • Fibrous ankylosis is characterized by intracapsular fibrous adhesions and fibrous changes in capsular ligaments. The results include severely limited mouth opening, no pain, no joint sounds, deviation to the affected side, and decreased movement to the contralateral side.

Temporomandibular joint ankylosis Treatment:

• Surgical correction is the treatment choice.
• Reankylosis is a common complication irrespective of the surgical technique used to treat TMJ ankylosis.

Question 5. Dislocation of mandible
(or)
Condylar dislocation.
Answer:

• The condyle is positioned in front of the articular eminence and cannot be returned to the normal position without manipulation.
• A mandibular dislocation occurs due to muscular incoordination during wide-opening like yawning. Trauma rarely causes this condition.
• The condition may be either unilateral or bilateral.
• The inability to close the jaws following opening and pain related to muscle spasms are the major symptoms.

Mandible Management:

• The condyle is repositioned manually by standing in front of the seated patient and placing the thumb lateral to the mandi¬bular molars on the buccal shelf of the bone.
• The remaining fingers of each hand are placed under the chin. Simultaneous pressing the posterior mandible in downward and backward movement and raising the chin will reposition the condyle.
• If muscle spasm is severe, diazepam can be advised.
• Recurrent and chronic dislocations are treated with surgery.

Question 6. Osteoarthritis of the temporomandibular joint
(or)
Degenerative disorder of temporomandibular joint.
Answer:

• The temporomandibular joint osteoarthritis (OA) is a unilateral, degenerative disorder.
• It is characterized by a break in the articular cartilage, changes in bone morphology, and disintegration of the synovial tissues causing pain and restricted movements of the jaw.
• The characteristic structural changes are disorganization and loss of articular surfaces and proliferation of tissues in and adjacent to these surfaces.
• The temporomandibular joint is the first joint to get affected with osteoarthritis. The patients present with symptoms including pain on opening, limited movement, grinding noise on function, history of recently stopped clicking sound, and deviation to the affected side during mouth opening.

Temporomandibular joint Radiographic Diagnosis: Narrow joint space, flat articular surface, bony projection from the degenerated cartilage (osteophytes), anterior lipping of the condyle, and Ely’s cysts (irregular radiolucencies near the articular surface).

Temporomandibular joint Management:

• The interdisciplinary team approach manages osteoarthritis.
• Physical therapy will relieve inflammation, pain, and functional improvement through various methods like TENS, ultrasound, iontophoresis, ice and stretch exercise, neuromuscular therapy, and postural and aerodynamic training.
• Arthroscopic surgery is used to flush out joint tissue fragments and inflammatory mediators.