My child has only 4 teeth and has begun grinding them I am unsure of the reason why he dose this but this can't be stopped. After consulting a dentist I was told nothing could be done, he is far too small for a mouth guard or to ask why and try to get him to stop. However I have found teething rusks do help he has something hard to chomp his teeth into and since they are new prehaps he just wants to use them.  My son is 9 months the dentist was not worried at all and its probably nothing but the sound his beautiful little teeth getting ground to dust makes just annoys me, so I am really tring to stop it.