The main reasons why babies and children grind their teeth in bed at night are as follows: First, because children do not brush and rinse their teeth before bedtime, a large amount of food residue accumulates on the dental surface, which stimulates the taste buds and leads to teeth grinding. Second, due to feeding the baby indigestible food before bedtime or having indigestion problems, resulting in abdominal pain and bloating during sleep, thus causing night grinding. Third, there is early contact of tooth tips in the dental row, children due to the gradual development of permanent teeth secondary to the alveolar bone, resulting in early contact of milk teeth, children’s temporomandibular joint and chewing muscles are very sensitive to early contact and will subconsciously grind down this early contact, causing the symptoms of night grinding. Fourth, babies with serious calcium deficiency, such as rickets children will have night grinding teeth. Fifth, infants and children with dental caries, pulpitis or periapical inflammation of milk teeth and other dental diseases in the mouth, due to the swelling of the teeth in the mouth, discomfort generated night grinding teeth. Sixth, intestinal parasites caused.