K.D.
My daughter had the same issue I spoke with the denstist about her teeth and it was happening because of the position of her teeth. they were not concerned. she actually wore them down so the two baby teeth in front top were so small when they fell out there was almost nothing to pull. but her adult teeth are in better alinement. teeth grinding can also indicate stress. so you may want to talk to you son about some stressor. K.