Bruxism, is the grinding of the teeth, and is typically accompanied by the clenching of the jaw. It is an oral parafunctional activity that occurs in most humans at some time in their lives. In most people, bruxism is mild enough not to be a health problem; however, 25% of people suffer from significant bruxism that will become symptomatic. While bruxism may be a diurnal or nocturnal activity, it is nocturnal bruxism which causes the majority of health issues, and can even occur during short naps. Bruxism is one of the most common sleep disorders.
Although teeth grinding can be caused by stress and anxiety, it often occurs during sleep and is more likely caused by an abnormal bite or missing or crooked teeth.