Abnormalities in the development of the jaw and face caused by sleeping with the mouth open can be gradually restored by surgical correction treatment after the cause is removed. The cause of open mouth breathing is mainly due to adenoid enlargement or rhinitis. Adenoid hypertrophy is mainly a pathological hyperplasia of the adenoids due to repeated stimulation by inflammation, which causes nasal congestion and open-mouth breathing. When rhinitis does not relieve nasal congestion, open mouth breathing will occur. It is recommended that when a child has open-mouth breathing, he or she should be admitted to the hospital in time to identify the cause and then undergo orthodontic treatment in the orthodontic department, which usually leads to better improvement. However, if it is delayed until adolescence or adulthood, the effect of simple orthodontic treatment may be poor, and orthognathic surgery in oral and maxillofacial surgery is needed at this time.