The temporomandibular joint (TMJ) is a sliding hinge that connects your jawbone to your skull. There is a joint on each side of the jaw. TMJ disorders are disorders in the temporomandibular joint that cause pain in the jaw joint and the muscles that control jaw movement.
The exact cause of a person's TMJ disorder is often difficult to determine. Your pain may be the result of a combination of factors, such as genetics, arthritis or a jaw injury. Some people with mandibular pain also tend to clench or grind their teeth (bruxism), although many people habitually clench or grind their teeth and never develop TMJ disorders.
In some cases, the pain and discomfort associated with TMJ disorders are temporary and can be relieved by self-managed care or non-surgical treatment. Surgery is often the last resort after conservative treatment has failed, but some patients with TMJ disorders may benefit from surgery.
Symptoms and signs of TMJ disorders may include:
Pain or tenderness in the jaw
Pain in the temporomandibular joint
Pain in and around the ears
Difficulty or pain in chewing
Locking the joints, difficult to open or close your mouth
TMJ disorders can also cause a clicking or jarring sensation when you open your mouth or chew.
The temporomandibular joint combines hinge movement and sliding motion. The bones that interact within the joint are partly covered with cartilage and separated by a small shock absorber, which usually keeps the motion steady.
TMJ disorder could happen if:
Disk erodes or moves out of its proper alignment
Articular cartilage is damaged by arthritis
The joint is damaged by a blow or other impact
However, in many cases, the causes of TMJ disorders are unclear.
Factors that may increase the risk of TMJ disorders include:
Various types of arthritis, such as rheumatoid arthritis and osteoarthritis
Permanent (chronic) grinding or clenching of teeth
Certain connective tissue diseases may affect the temporomandibular joint