Temporomandibular (TM) joint

The temporomandibular (TM) joints join the skull and lower jawbone. These gliding "ball and socket" joints are located just in front of each ear. They move when you open and close your mouth.

The TM joints are held together by muscles and other tissues that attach to the jawbone. The jawbone and the bone of the skull are separated by a disc made of cartilage, called the articular disc. This keeps the two bones from rubbing together.