Temporomandibular Joint Disorder (TMJ) occurs as a result of problems with the jaw, jaw joint, and surrounding facial muscles that control movement of the jaw. The temporomandibular joint is the hinge joint that connects the lower jaw to the bone of the skull. This joint is located immediately in front of the ear on each side of the head. The muscles attached to the jaw allow the jaw an incredible amount of movement: side-to-side and up and down. This flexibility allows us to chew, talk, and yawn.