Temporomandibular Joint Dysfunction (TMJ)

Temporomandibular joint (TMJ) syndrome is pain in the jaw joint that can be caused by a variety of medical problems. The TMJ connects the lower jaw (mandible) to the skull (temporal bone) in front of the ear. Certain facial muscles that control chewing are also attached to the lower jaw. Problems in this area can cause head and neck pain, facial pain, ear pain, headaches, a jaw that is locked in position or difficult to open, problems with biting, and jaw clicking or popping sounds when you bite. Temporomandibular joint syndrome is also referred to as temporomandibular joint disorder. Overall, more women than men have TMJ syndrome.

The TMJ is comprised of muscles, blood vessels, nerves, and bones. You have two TMJs, one on each side of your jaw.

Muscles involved in chewing (mastication) also open and close the mouth. The jawbone itself, controlled by the TMJ, has two movements: rotation or hinge action, which is opening and closing of the mouth, and gliding action, a movement that allows the mouth to open wider. The coordination of this action also allows you to talk, chew, and yawn.

If you place your fingers just in front of your ears and open your mouth, you can feel the joint and its movement. When you open your mouth, the rounded ends of the lower jaw (condyles) glide along the joint socket of the temporal bone. The condyles slide back to their original position when you close your mouth. To keep this motion smooth, a soft disk of cartilage lies between the condyle and the temporal bone. This disk absorbs shock to the temporomandibular joint from chewing and other movements. Chewing creates a strong force. This disk distributes the forces of chewing throughout the joint space.