She grinds her teeth in her sleep. 她睡觉磨牙。
She was so angry she ended up grinding her teeth and giving herself a sore jaw.
My dentist has given me a mouthguard to stop me grinding my teeth in my sleep.
The hygienist said he'd been grinding his teeth.
When you grind your teeth it wears down the enamel.
See also: grind verb (RUB)