Bruxism, better known as teeth grinding, can be caused by stress and anxiety, an abnormal bite, missing and crooked teeth, or it can be due to sleep disorder. When under stress, many people find themselves grinding their teeth or clenching their jaws during sleep. Over time, bruxism may lead to symptoms such as dull headaches or a sore jaw. Severe grinding can lead to painful, loose teeth or fractures in your teeth. Consult your dentist to determine if you have a problem. You may need a mouth guard to protect your teeth during sleep.