I'm a lifelong teeth grinder, chomper, chewing in my sleep first degree Bruxer. I've got the flattened teeth, cracked teeth and even the roots of my rear teeth driven up into my sinuses to prove it. I've been doing it all my life. Usually if I have a bowl of cereal before bed, I won't grind. I also try to go to sleep with my mouth open. Man, some mornings I've woken up with my jaw literally stuck shut and ears ringing like fire engines.