Gummy smile is not a disease, it is a common facial pattern. Due to the excessive exposure of the lip-side gums of the maxillary anterior teeth when smiling (usually greater than 2mm), it destroys the beauty and harmony of the face to some extent and brings a psychological burden to people, so there is often a clinical requirement for correction. Severe bony causes of dewlap smile must be corrected by orthognathic surgery, but some people do not have bony occlusion problems and cannot be corrected by orthodontic or periodontal surgery treatment, or candidates who do not accept other treatment methods can make an incision in the intraoral maxillary vestibular groove, find out the upper lip square and lifting muscles on both sides, cut off and adjust the stops, and properly extend the mucosal tissues in the ligature area to loosen the upper lip and by After the surgery, the function of the lip muscle is trained so as to effectively increase the length of the upper lip and achieve the purpose of correction. The surgery is performed before the operation with routine blood and serological tests to exclude contraindications to surgery, and is performed under local anesthesia on an outpatient basis, with no important blood vessels and nerves at the surgical site and no incisions on the exterior skin, with positive surgical results and good safety.