Pain is caused by the muscles in and around the jaw joint tightening up.
Joint noises occur if the disc of cartilage moves out of its normal position between the bones of the jaw joint. Most commonly, the cartilage slips forward and a noise is made when it returns to its normal position in between the bones of the jaw joint. The noises sound louder to some patients than others because the joint is just in front of the ear.
The ligaments and muscles surrounding the joint can, in turn, go into spasm, producing pain and limited mouth opening.