Temporomandibular joint (TMJ) disorders


Temporomandibular joint (TMJ) disorders are a group of medical conditions that cause the jaw joint (called the temporomandibular joint or TMJ) to be sore and painful. The TMJ connects the lower jaw, called the mandible, to the temporal bone of the skull, which is located in front of the ear on both sides of the head. The TMJ allows the jaw to move up and down and side to side. These movements are important for many functions, including talking, chewing food, and yawning.
TMJ disorders are often divided into three categories: myofascial pain, internal derangement, and arthritis. Myofascial pain is the most common TMJ disorder. It occurs when the muscles that control the jaw are sore or tender. The cause of myofascial pain remains unknown. Internal derangement of the joint occurs when the joint becomes injured by a blow to the jaw. A TMJ disorder may occur if the injury causes the jaw to become dislocated, a disc becomes displaced, or the rounded ends of the lower jaw (called condyles) become damaged. Arthritis, which causes inflammation and swelling of joints, may also affect the TMJ. A patient may have one or more of these TMJ disorders, which may affect one or both sides of the jaw.
Several other medical problems, including sleep disturbances, chronic fatigue syndrome, and a painful condition that affects the muscles and other soft tissues in the body (called fibromyalgia), have been associated with TMJ disorders. However, it is unknown if these health problems share a common cause with TMJ disorders.
The exact number of people who have TMJ disorders remains unknown. However, as many as 10 million Americans experience symptoms related to TMJ disorders, according to the National institute of Dental and Craniofacial Research (NIDCR). For unknown reasons, these disorders occur more often in women than men. In general, TMJ disorders are most likely to develop in individuals who are 20-40 years old.
Most patients with TMJ disorders only experience temporary symptoms, which often come and go. Although pain may occur when the jaw is not moving, it is generally worse when the jaw is being used. For many, the pain eventually goes away with little or no treatment. Some patients may benefit from self-managed care or nonsurgical treatments. However, for a small number of patients, TMJ disorders may cause serious long-term pain. In such cases, patients may need to undergo dental or surgical procedures to treat the symptoms.

Related Terms

Arthritis, arthrocentesis, biteplate, condyles, internal derangement, jaw disorder, jaw pain, joint disorder, joint inflammation, mandible, myofascial pain, splint, temporal bone, temporomandibular joint, TMJ.