violently, often resulting in ligament tears, stretching of structures to their limits and discal tearing. All can lead to the development of TMJ symptoms.

Bruxism/Clenching: Bruxism, the grinding of the teeth, usually occurs during sleep. Clenching can occur throughout the day or night. Both can be directly related to TMJ, either as a trigger for muscle spasms or as a result of malocclusion. Constant grinding also causes pressure on the TMJ. Bruxing can put pressure on the articular disc, squeezing out synovial fluid and robbing it of lubrication.

Loss of teeth: When a tooth is lost, the teeth around it tend to shift to fill the space. This change can alter the way the teeth gear in relation to the joint, causing symptoms to develop.

Malocclusion: Malocclusion is the abnormal contact of opposing teeth with respect to the temporomandibular joint that interferes with the efficient movement of the jaw during mastication. It is one of the most frequent triggers of TMJ syndrome. Malocclusion, even on a minute scale, can trigger the spasm of muscles, resulting in pain.

Systemic Diseases: The TMJ, like any other joint, is susceptible to any of the systemic diseases. Immune disorders such as osteoarthritis, rheumatoid arthritis, psoriatic arthritis and systemic lupus erythematosus and electrolyte imbalances can produce inflammation and muscle cramping in the TMJ. In addition, viral infections can cause damage to the surfaces of the TMJ.

Disc Displacement: The jaw joint, in addition to being a ball and socket joint, glides forward and backward. When functioning correctly, the articular cartilage lies between the condyle head of the mandible and the roof of the joint. It normally follows the condylar head in its forward and backward movement.

If the ligaments that hold the disc to the condylar head are injured, the disc can slip out of place and can no longer serve as a normal cushion between the lower and upper parts of the jaw. Typically, the disc is pulled forward.

Mild displacements can cause a clicking or popping sound in the joint and sometimes can be painful. Permanent damage may result.