Your oral health can be a surprisingly important factor as you sink your teeth (quite literally) into diving. The temporomandibular joint (TMJ), a ball and socket joint located just in front of the ears on both sides of the head, attaches the lower jaw to the skull. It is one of the body's most complex joints and contains a small disc which under certain circumstances can become unstable. When it does, a clicking sensation can occur as it slips in and out of place. This in turn can cause a syndrome that includes ear pain, sore jaw muscles, temple/cheek pain, locking of the jaw, difficulty in opening the mouth fully, or frequent head/neck aches.