Been lifting regularly for 8 months. I begin noticing my upper and lower front teeth were beginning to chip a little.  Anybody else have this problem?  What did you do about it?  I worked out today and noticed that even knowing I had this problem, I still set my jaw when lifting in a way that grinds my front teeth.   My thinking is to wear a mouth guard.  If nothing else it will make me more aware of this problem.

I don't grind my teeth and I lift pretty heavy.

Could just be the way you grunt/technique.  Try chewing some gum maybe?

Ball gag will solve that problem and maybe even help with your underbite.

I have a lot of severe pains from various injuries and find myself grinding my teeth when doing just about anything halfway strenuous now, so you are not alone.  I have considered getting a mouth guard myself because I often feel small pieces of my teeth floating around afterwards.