The temporomandibular joint (TMJ) is 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 your 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.
Other jaw disorders
Chins that protrude or “sink in,” or teeth do not seem to fit together correctly, are sometimes the result of upper and lower jaws growing at different rates, or both jaws growing too much or too little. People with such problems often have a jaw abnormality that results in poor teeth alignment, and sometimes experience problems eating or even swallowing.
If you have a poorly formed chin or misaligned teeth, you may be a candidate for orthognathic (jaw) surgery.
Speech and swallowing problems often occur because the tongue and lips attempt to compensate for poor jaw alignment, and move around awkwardly.
Injury to the jaw and birth defects can also affect the alignment of your jaw.