If you take it literally, the result could be grinding your teeth or clenching your jaws. It's called bruxism, and often it happens as we sleep, caused not just by stress and anxiety but by sleep disorders, an abnormal bite or teeth that are missing or crooked.
Symptoms include a dull headache or a sore jaw.
You could have teeth that are painful or loose from severe grinding. This can lead to fractures in your teeth.
Your dentist can fit you with a mouth guard to protect your teeth during sleep.
If stress is the cause you need to find a way to relax! Physical therapy, muscle relaxants, counseling and even exercise may help reduce tension.