Trauma to the jaw or temporomandibular joint plays a role in some TMJ disorders. But for most jaw joint and muscle problems, scientists don’t know the causes. For many people, symptoms seem to start without obvious reason. Research disputes the popular belief that a bad bite or orthodontic braces can trigger TMJ disorders. Because the condition is more common in women than in men, scientists are exploring a possible link between female hormones and TMJ disorders.
There is no scientific proof that clicking sounds in the jaw joint lead to serious problems. In fact, jaw clicking is common in the general population. Jaw noises alone, without pain or limited jaw movement, do not indicate a TMJ disorder and do not warrant treatment.
The roles of stress and tooth grinding as major causes of TMJ disorders are also unclear. Many people with these disorders do not grind their teeth, and many long-time tooth grinders do not have painful joint symptoms. Scientists note that people with sore, tender chewing muscles are less likely than others to grind their teeth because it causes pain. Researchers also found that stress seen in many persons with jaw joint and muscle disorders is more likely the result of dealing with chronic jaw pain or dysfunction than the cause of the condition.