Q: How can I tell if I'm grinding my teeth at night?

A: If you wake up with a headache and sore jaw muscles, you may be a tooth grinder. Another sure sign is if your partner elbows you in the ribs in the middle of the night. "The sound of teeth grinding can be really grating on the nerves," says dentist Howard Glazer, of Fort Lee, New Jersey, who is president of the Academy of General Dentistry.

Teeth grinding, or bruxism, is often related to stress. It also can be caused by crooked or missing teeth or by something that creates an abnormal bite, such as a high spot on a molar.

To diagnose bruxism, dentists look for flattened spots on the teeth. Treatment includes smoothing down those high spots and behavior modification for stress reduction. Your dentist also may recommend a mouth guard or a custom-made splint to be worn at night. These prevent teeth from coming together, which interrupts the grinding and gives muscles a chance to relax.