I read that tooth grinding is the brain "twiddling its thumbs". The book recommended eating a bagel or other "chewy" (apple works too) food before bed and wear out the jaw muscles some and it would lessen. Maybe chew gum a lot during the day? I think I tried (my dentist says I grind/ground my teeth (this was many many years ago -- I've never broken any, or anything like that) out the food before bed thing and didn't really notice any difference but I never noticed I ground my teeth, either :-)