For most people, clenching their teeth while sleeping is a normal physiological phenomenon, especially for children during the period of tooth replacement is also more common, generally do not worry too much. However, if you clench your teeth hard and often while sleeping, it may be caused by bruxism. And there are many causes of teeth grinding, mainly related to mental tension, dental problems, sleep disorders, disease stimulation, genetics and many other reasons. 1, mental tension: excessive pressure in learning and work, emotional tension, excessive fatigue, or excessive excitement before bedtime, etc., may lead to the contraction of the bite muscle when entering sleep, and then the situation of clenching teeth to sleep; 2, dental problems: such as misalignment of teeth, tooth loss, buck teeth, upper and lower teeth can not kiss. buck teeth, upper and lower teeth can not match, etc., may lead to night bite muscle or chewing muscle contraction, resulting in some people clenching their teeth to sleep; 3, sleep disorders: such as dreaming, apnea, etc., can lead to abnormal transmission of information from the central nervous system, resulting in clenching teeth to sleep; 4, disease stimulation: gastrointestinal disorders, parasitic infections, calcium deficiency, rickets, endocrine disorders, imbalance of hormone levels, allergies, hyperthyroidism, etc. Diseases, may stimulate or inhibit the cerebral cortex, triggering some people to appear to sleep and clench their teeth. In addition, there are also genetic reasons, that is, some parents have the condition of clenching their teeth in bed, the child may also appear to clench their teeth. Regular clenching of teeth in bed is likely to cause wear and tear on teeth, so it is recommended to relax before bedtime, reduce the consumption of foods that cause excitement such as chocolate and coffee, and also try to avoid smoking. Pay attention to calcium supplementation, deworming, maintain good oral hygiene, and orthodontic treatment if there are teeth deformities.