Follow-Up: I have researched this issue quite well. In my opinion, there are several factors to examine: 1) Physical / structural problems: Misaligned teeth or improper cranial development causes stress in the jaw muscles. This triggers grinding, clenching and / or snapping the jaws shut repeatedly at night. For some groundbreaking developments on correcting this, see www.ndnd.com, regarding 'neuro-cranial restructuring'. This procedure will loosen the bone joints in your head so that they can re-seat themselves more properly. Surprisingly, it's not that painful, and has numerous benefits. Orthodontia and bite correction may also solve the problem, as could a special mouth appliance that reduce muscle stress may work. Some appliances may reduce this stress, while others only serve to reduce the damage caused by the grinding itself. To this effect, and hard appliance is better than a soft one, because it is more slippery, and will not allow the user to 'torque out' on it, like the soft gummy kind. The torquing can loosen teeth. Improper jaw, teeth and head development is primarily caused by poor diet during childhood development. To learn more about this 'diet connection', do a search on Dr. Meinig's book, 'Root Canal Coverup', or search the works of Dr. Weston Price. 2) Physical stress: Not enough sleep & exercise, a continuous low-grade infection, poor diet, toxic substances (such as mercury from your 'silver' fillings) and allergies can all cause bruxism. 3) Emotional stress: Self-explanatory. In my opinion, biofeedback devices are best suited for this. However, I doubt if they would do too much good for the afore-mentioned causes of bruxism. SPECIAL NOTE: Regarding 'silver' amalgam fillings. These fillings are 50% mercury, which is an extremely toxic material. It can screw up your mineral balance, and cause bone loss in your teeth, in addition to NUMEROUS other problems. The mercury leaks as vapor, or may even crumble off into your mouth. It's dangerous even if you don't grind your teeth. But many readers are now grinding their fillings at night - right into your mouth. There's a lot of info on the web about this: search it out! Also, if you live alone, the only way you may know whether a 'cure' is working would be to get a sensor device. The only one I know of can be obtained by calling 888-BRUX NOT. Good luck. - 'Dr.' Kevin 2)