Located on both sides of the head, where the jawbone meets the skull,  the temporo-mandibular joint (TMJ) is used during talking, eating, swallowing, etc.  This joint can become displaced or overused resulting in severe tension headaches, as well as sharp pain in the jaw.  TMD signs and symptoms include pain and tenderness in or around the ear, the jaw joint, or the muscles of the jaw, face or temples.  Other symptoms include issues with opening/closing your mouth, and a clicking/popping/crunching or grinding noise when you yawn, chew or open your mouth.