The pain associated with TMD is caused when the temporomandibular joint (the joint that connects the lower jaw to the skull) is damaged or has deteriorated or when the muscles surrounding the joint are malfunctioning, causing an imbalance in the movement of the jaw joint. For instance, TMD can be caused by the impact of an auto accident, an improper bite that causes stress on the chewing muscles or by behaviors associated with stress, such as clenching the jaw or grinding the teeth.