Bruxism can occur during sleep (sleep bruxism) and while awake (awake bruxism). In some people, bruxism causes headaches, neck pain, and/or jaw pain. The most severe and extensive grinding and clenching occurs during sleep. People may be oblivious to their bruxism, but family members might notice. Bruxism can abrade and eventually wear down enamel and dentin in the crowns of teeth, damage metal or ceramic dental crowns, and cause teeth to become mobile.
Bruxism is considered a multifactorial condition. Well-established risk or contributing factors include sleep disorders and emotional stress (eg, anxiety). Tooth abrasion and erosion is often worse in patients who also have gastroesophageal reflux disease Gastroesophageal Reflux Disease (GERD) Incompetence of the lower esophageal sphincter allows reflux of gastric contents into the esophagus, causing burning pain. Prolonged reflux may lead to esophagitis, stricture, and rarely metaplasia... read more 
(GERD) and/or obstructive sleep apnea Obstructive Sleep Apnea (OSA) Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ; the understanding of the association between sleep apnea and bruxism is evolving.
Treatment requires that the patient consciously try to reduce bruxism while awake. Plastic oral appliances (night guards) that prevent occlusal contact by fitting between the teeth can be used while sleeping. When symptoms are severe, a guard can also be used during the day. Usually, such devices are custom-made and fitted by dentists. However, if the only problem is tooth wear, over-the-counter (OTC) heat-moldable devices fitted at home are available, but a dental evaluation should first be done to assess the severity of wear and determine whether an OTC device is adequate. Mild anxiolytics, particularly benzodiazepines, may help until a night guard is available but should not be used for extended periods.
(See also Myofascial Pain Syndrome Temporomandibular Myofascial Pain Syndrome Temporomandibular myofascial pain syndrome (previously known as myofascial pain and dysfunction syndrome [MPDS or MFPDS]) can occur in patients with a normal temporomandibular joint. It is caused... read more .)
