Pain in the jaw comes from a wide variety of things. Sometimes, jaw pain is caused by an injury. In many cases, however, jaw pain is caused by a disorder of the temporomandibular joint (TMJ), the ball and socket joint on each side of your jaw. This joint connects the lower jaw to the skull near the front of the ear. A properly formed TMJ allows the jaw to move smoothly in various directions, and plays an important role in talking, chewing, and yawning.
Temporomandibular joint disorders (TMDs) are caused by problems with the muscles of the jaw or the joint itself. A clicking or popping sound when opening the mouth wide, such as in yawning, may be a sign that you have a problem with your TMJ.
TMDs result from a variety of things, such as traumatic blow to the head (including whiplash), teeth grinding or clenching, and arthritis.
People with TMD sometimes experience chronic headaches, earaches, and facial and dental pain.