TMJ stand for Temporo Mandibular Joint. This is the joint that is the hinge for your jaw. Tooth clenching, gum chewing, eating big sub sandwiches, chewing on ice cubes and other trauma to the jaw can cause this. The pain seems as if it is coming right from the ear. Treatment usually includes resting the jaw (which means not chewing) anti-inflammatory antibiotics and correction of problems with the bite.