Children like to grind their teeth in bed may be due to the following reasons: First, before going to bed without a good brush and rinse, the teeth will be stored in the food residue, in sleep will stimulate the taste buds, resulting in teeth chewing movement during sleep, resulting in the occurrence of the phenomenon of night grinding teeth. Second, sleep before eating indigestible food led to sleep bloating, abdominal pain, will also appear the phenomenon of night grinding teeth. Third, the oral cavity has tooth decay, pulpitis or periapical inflammation and other diseases, in sleep due to the swelling of the teeth discomfort will also appear night grinding symptoms. Fourth, see in children with serious calcium deficiency, such as rickets children will also occur night grinding teeth. Fifth, if children are in the stage of permanent teeth and milk teeth replacement, due to the continuous eruption of permanent teeth will make the milk teeth appear local cusp early contact, will stimulate the temporomandibular joints, muscles cause both functional movement enhancement, thus causing the occurrence of night grinding teeth.