There are several reasons why children grind their teeth during sleep: first, tooth decay, pulpitis or periapical inflammation and other diseases, making the teeth swollen and uncomfortable during sleep, which will cause teeth grinding. Second, children do not brush their teeth and rinse their mouths carefully before going to bed, so that a lot of food residues are stored on the tongue, which will stimulate the taste buds and taste nerves, resulting in children grinding their teeth during sleep. Third, for children with severe calcium deficiency, especially rickets patients, prone to the phenomenon of night grinding teeth. Fourth, children eat indigestible food before bedtime, or children’s own digestive function is not yet well developed, resulting in abdominal pain and bloating during sleep will also cause night grinding. Fifth, children are in the replacement stage of permanent teeth and milk teeth, due to the gradual eruption of permanent teeth, will cause early contact with the tips of milk teeth, will also cause night grinding.