When under stress, many people find themselves grinding their teeth or clenching their jaws. It is often something we do when we sleep. Bruxism can be caused by stress and anxiety, an abnormal bite or missing and crooked teeth, or it can be due to sleep disorders. Bruxism can lead to symptoms such as dull headache or a sore jaw. Severe grinding can lead to painful or loose teeth which can lead to fractures in your teeth. Your dentist can fit you with a mouth guard to protect your teeth during sleep.