TMJ disorders are multifactorial in origin. Trauma to the jaw or temporomandibular joint plays a role in some disorders as this can lead to stretching of the joint ligaments or displacement of the articular disc. Other risk factors include systemic arthritic conditions (rheumatoid arthritis), jaw clenching, teeth grinding, fibromyalgia, and congenital deformities. Stress is thought to play a role is some but not all cases. For many people, symptoms may start without an obvious trigger. TMJ disorders most commonly occur in women between the ages of 30 and 50 and consequently a hormonal contribution is also possible. What is clear now through research is that a bad bite or malocclusion is not now considered a major contributing factor.