Generally, when sleeping, the teeth are in a loose state, neither occluded nor completely separated. If people sleep, the upper and lower teeth are always in the state of clenching or separation, so that the closed mouth muscle group or the opening muscle group is often in a state of contraction will cause muscle fatigue, prolonged muscle fatigue may lead to muscle pain. Generally in 24 hours, normal people upper and lower teeth contact time is only a total of ten minutes, but clenching or night grinding teeth of the population, in the case of non-chewing will also make the upper and lower teeth frequent contact, not only will cause serious wear and tear of the teeth, but also increase the periodontal tissues, chewing muscles and temporomandibular joints of the burden of the oral and maxillofacial system caused by the damage to varying degrees. Therefore, when sleeping with open mouth breathing or teeth clenching, nocturnal teeth grinding, need to go to a professional dental hospital for intervention and treatment, it is recommended to maintain good oral hygiene habits, brush and rinse after eating, if there are abnormalities of teeth opening and closing, it is recommended to go to the orthodontics department of the regular hospital as soon as possible to be examined and treated.