Temporomandibular Joint (TMJ) Syndrome refers to an acute or chronic inflammation and disorder of the temporomandibular joint (jaw joint). The jaw joint connects the mandible to the skull and the muscles that control chewing. If you place your fingers just below your temples and open your mouth, you will be able to feel the jaw joint on each side of your head. Pain in the jaw can be due to trauma, repetitive unconscious jaw movement such as grinding or clenching of the teeth, misalignment of occulusal surfaces of the teeth, excessive gum chewing, nail biting, lip biting when one is stressed, the size of food eaten and degeneration of joint cartilages. Signs and symptoms include headaches, toothaches, ear pain, ringing in the ears, neck, shoulder and back pain, pain behind the eyes, swelling and limitations when opening your mouth.