As the main support of the facial contour, the mandible is an important part that affects the beauty of the face, and the shape of the mandible affects the entire facial contour. In Eastern aesthetic culture, the melon and oval face shape can show the unique femininity, gentleness and quietness of Eastern women. The “melon face” and “goose egg face” are very popular, and the face shape seems to somehow weaken women’s temperament and charm, which makes more and more women ask for “facial reshaping surgery This has led more and more women to request “facial reshaping”. Protruding jaw angle with chewing muscle hypertrophy is also called squarejaw or square face deformity, and among those who request jaw angle surgery, a considerable number of people do not have severe jaw angle or chewing muscle hypertrophy. In this sense, mandibuloplasty is not only the removal of the protruding jaw angle, but also the requirement that the newly formed jaw angle has a harmonious and natural contour, whether from the front or from the side, is fuller and softer and has a three-dimensional sense, so that the front and side appearance of the face meet the aesthetic requirements. The use of surgical correction of square jaw deformity was first reported by Gurney in 1947, and the surgery was done through an extra-oral approach. However, the extra-oral approach leaves a visible scar on the face, which is contrary to the original intention of cosmetic surgery to “put the icing on the cake”. The intraoral approach for partial excision of the bite muscle and mandibular angle was first reported by Converse (1951), which avoided facial scars, but at that time, the conditions were limited and the intraoral view was not good, so the operation was not convenient. Currently, with the introduction and application of various high-efficiency jaw surgery power and cold light source illumination systems, it has become easier and safer to complete mandibular angle osteotomy via the intraoral approach. For a skilled surgeon who is familiar with the anatomy of the jaws, the intraoral approach to mandibular angioplasty makes it easier to perform a fine revision of the entire jaw shape to achieve a satisfactory postoperative result. The disadvantage of the intraoral approach is that the surgical field of vision is poor and not easy for beginners. The surgeon must be equipped with osteotomy tools such as a micro bone saw or bone drill and an optical fiber intraoral illumination system, and must receive systematic and rigorous training, including proficiency in the use of osteotomy instruments. The patient’s facial shape should be accurately and comprehensively analyzed and evaluated before surgery in order to achieve the ideal surgical result. For example, some patients not only have overdeveloped mandibular angle and chewing muscle hypertrophy, but also have a wide facial area, such as wide zygomatic arch, so mandibuloplasty alone may not achieve the ideal treatment effect, and need to perform zygomatic bone and zygomatic arch plastic surgery at the same time. In some patients with receding chin and enlarged cheek fat pad, if chinplasty and cheek fat pad removal are performed at the same time, very satisfactory results can be achieved. There are two basic procedures for intraoral approach mandibuloplasty: 1. For patients with an enlarged mandibular angle and a lateral angle close to 90 degrees, a mandibular angle osteotomy is required to form a new mandibular angle with a beautiful angle. The osteotomy should form a new mandibular angle, and should not be a simple excision. The simple resection is like cutting a square table corner, cutting off one and leaving two, forming a double-angle deformity, making the side shape less than ideal. 2. A considerable number of patients do not have an obvious overdevelopment of the jaw angle, and the lateral shape of these patients is basically normal, but the posterior part of the mandible appears to be too wide or the jaw angle is abducted to the side. For patients with basically normal lateral morphology, removal of the mandibular angle will not only destroy the natural lateral curvature of the mandible, but also may not achieve the corrective effect of narrowing the width of the lower part of the face. The use of lateral mandibular cortical osteotomy (also called modified sagittal splitting of the mandible) to correct this type of deformity can achieve satisfactory results. The surgery only reduces the lateral width of the mandible in the area of osteotomy, while preserving the original normal lateral contour of the mandibular angle, with satisfactory results in both front and side after surgery. To achieve a fine surgical result, jaw angioplasty should be performed under general anesthesia. Antibiotics are used for 3-6 days after surgery to prevent infection. You can eat liquid food on the second day after surgery, and the swelling can be basically reduced and normal eating can be resumed one week after surgery.