Temporomandibular joint (TMJ) syndrome is pain in the jaw joint that can be caused by a variety of medical problems. The TMJ connects the lower jaw (mandible) to the skull (temporal bone) in front of the ear. Certain facial muscles that control chewing are also attached to the lower jaw. Problems in this area can cause head and neck pain, tinnitus, vertigo, facial pain, ear pain, headaches, a jaw that is locked in position or difficult to open, problems with biting, and jaw clicking or popping s