The temporomandibular (tem-puh-roe-man-DIB-u-lur) joint, also called TMJ, acts like a sliding hinge. It connects the jawbone to the skull. There is one joint on each side of the jaw. TMJ disorders — a type of temporomandibular disorder or TMD — can cause pain in the jaw joint and in the muscles that control jaw movement.
The exact cause of TMJ disorder is often hard to determine. The pain may be due to a mix of factors, including habits such as teeth clenching, gum chewing and nail biting; stress; and painful conditions that occur along with TMJ disorder such as fibromyalgia, osteoarthritis or jaw injury. The habit of teeth clenching or grinding also is known as bruxism.
Most of the time, the pain and discomfort related to TMJ disorders lasts for only a limited time. Self-managed home care, physical therapy for the jaw and the use of a mouth guard can be effective in treating symptoms of TMJ disorder. Surgery is usually a last resort after conservative measures have failed. But surgical treatments may help some people with TMJ disorders.

TMJ disorders affect the temporomandibular joint, located on each side of your head in front of your ears. A soft cartilage disk acts as a cushion between the bones of the joint, so the joint can move smoothly.
Symptoms of TMJ disorders may include:
TMJ disorders also can cause a clicking sound or grating sensation when you open your mouth or chew. But if there's no pain or limitation of movement related to your jaw clicking, it's likely that you won't need treatment.
Seek medical attention if you have constant pain or tenderness in your jaw that occurs suddenly or during jaw movements or if you can't open or close your jaw completely. Your dentist, TMJ specialist or other healthcare professional can discuss possible causes and treatments.
The temporomandibular joint combines a hinge action with sliding motions. The parts of the bones that work together in the joint are covered with cartilage and separated by a small shock-absorbing disk. This disk usually keeps the movement smooth.
Painful TMJ disorders can happen if:
Many times, the cause of TMJ disorder has a variety of causes and is hard to identify.
Factors that may raise the risk of getting TMJ disorders include: