The Temporomandibular joint (TMJ) acts like a sliding hinge, connecting your jawbone to your skull. 

The exact cause of a person's TMJ disorder is often difficult to determine. Your pain may be due to a combination of factors, such as genetics, arthritis or jaw injury. 

A Temporomandibular joint (TMJ) facture occurs when the mandible and/or temporal bone is broken near or through the TMJ, the joint connecting the jaw bone to the skull. Like other bones in the body, the mandible, also known as the jaw bone, and the temporal bone, the bone on the skull that forms the upper part of the jaw joint, can break when subjected to trauma. TMJ fractures occur due to direct trauma to the face. The jaw most often breaks along the condyles, which are rounded projections on the jaw bone. Fracture also may occur with a dislocation of the joints.

Motor vehicle accidents, assault, sports injuries, and falls are the most common causes of TMJ fractures. 

Following a TMJ fracture, especially if the inside surface of the mouth is torn, there also is a risk of infection, which can lead to osteomyelitis of the jaw. Blows to the head severe enough to cause a TMJ fracture can also cause a concussion.

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