Temporomandibular Joint

People have two temporomandibular (jaw) joints, one located in front of each ear, that connect the lower jaw (mandible) to the temporal bones of the skull. These hinge joints allow for up-and-down and side-to-side movement of the jaw, so people can perform such functions as opening and closing the mouth, speaking, chewing, and yawning. Unfortunately, the temporomandibular joint (TMJ) is also the most common non-dental source of pain in the head and jaw area. Any problem with the jaw joints and the facial muscles that control them are known as a temporomandibular disorder (TMD), but many people incorrectly refer to this as TMJ, after the joint.

The National Institute of Dental and Craniofacial Research of the National Institutes of Health estimates that 10.8 million people in the United States suffer from TMD at any given time. There is no known cause for TMD, but dentists believe symptoms arise from an injury to the jaw, the joint, or the muscles in the head and neck. For example, whiplash or blunt force trauma to the head or jaw could possibly lead to TMD.

TMD happens more often to women than men, and it’s most common among people between the ages of 20 and 40.

When a problem is related to the muscle disorders, this is called myalgia/myofascial pain (pain from sore muscles). This pain is typically caused by grinding or clenching the teeth and typically results in pain to the jaw, face, head, neck and eventually translating to the shoulder, arm, back, hip, knee, and foot.

Headaches are a common TMD symptom. Other symptoms may arise, such as ringing in the ears, ear pain, diminished hearing, dizziness or vertigo, and visual disturbances. Pain usually appears in the joint itself, in front of the ear, but it may move elsewhere in the skull, face, or jaw and lead to headaches, dizziness, and even migraines.

When the joints move, sounds, such as clicking, grating, and/or popping may be heard by the patients and others nearby.

TMD may also cause the jaw to lock wide open (dislocation) or the mouth may not fully open. Or, upon opening, the lower jaw may deviate to one side, which may cause the face to swell on the affected site. Teeth may not fit properly together and the bite may feel odd.