The temporomandibular (TM) joints join the skull and lower jawbone (mandible). These gliding "ball and socket" joints are separated by a disc made of cartilage, which keeps the two bones from rubbing together.
These joints are located just in front of each ear. They move when a person opens and closes the mouth.
The TM joints are stabilized by muscles that attach directly to the jawbone. If these muscles are strained or tense, jaw pain may result.
Sometimes TM joint problems result when the cartilage disc tears or moves out of its normal position (disc displacement).