The National Institutes of Health estimates that 5 to 10 percent of Americans have TMD, or problems affecting the jaw joint and/or muscles. Your temporomandibular joints are located where the skull connects to your lower jaw. To feel these joints, place your fingers in front of both ears and open your mouth. The muscles on the sides of your head and face control the movements of the joints. Researchers believe women between 20 and 40 may be more likely to suffer from TMD due to hormone levels.

Updated: November 2008