What is temporomandibular joint dysfunction?

The temporomandibular joints (TMJ) connect the lower jaw, or mandible, to the temporal bones at the sides of the head. These joints are flexible, allowing the jaw to move smoothly up and down and side to side, and enabling us to talk, chew, and yawn. TMJ dysfunction involves face pain, clicking sounds in the TMJ, and limited movement of the jaw. About 33 percent of the population has TMJ dysfunction, and as many as 75 percent have some symptoms.