Jaw muscle contraction, during certain stages of sleep, results in intense jaw clenching and/or vigorous teeth grinding. This pressure on the teeth will speed up the bone loss from periodontal disease, and can cause headaches and problems with the jaw. Occlusal guards help to minimize the damage from clenching. The NTI is an inch-wide mouthpiece that sits between the two upper and lower front teeth. It's designed to limit grinding and clenching by preventing the molar and canine teeth from touching, therefore relaxing tense muscles in the jaw and face. Invented in 1989 by Dr. James Boyd, the NTI received clearance from the U.S. Food and Drug Administration as a device to treat migraines and tension headaches in June. The creators of NTI claim 82% of migraine and headache sufferers who use the device experience an average 77% reduction of pain within two months.

Chronic symptoms of the head and neck may be attributed to:

A . Headache (the temporalis muscle opens and closes the jaw)
B . Sinus pressure and pain (the lateral pterygoid muscle muscle moves the jaw side to side and foreward)
C. Neck pain and stiffness (the trapezius muscle stabilizes the skull during clenching and grinding)