B.R.
My 10 month-old son grinds his teeth (two on top and two on bottom). I asked my pediatrician about it and she says it's just that he's discovering these new things in his mouth and learning what to do with them. Also may feel good. She says there's really no way to make him stop since he is too young for a mouth guard. Also, not to worry because they are only his baby teeth, not that she thinks he will damage them anyway.