Maxillofacial deformity is a facial deformity caused by abnormal development of the maxillofacial bones or other acquired factors, such as abnormalities in the volume and shape of the maxillofacial bones and the relationship between the upper and lower jaws and other bones in the craniofacial area. The main disciplines of orthognathic surgery, plastic surgery, and craniomaxillofacial surgery are the research and treatment of maxillofacial deformities. The treatment of maxillofacial deformity has a history of more than 100 years, in 1849 Hullihen first reported a case of post-burn scar contracture caused by mandibular deformity, through the osteotomy can be corrected, this is the earliest modern medical literature recorded in the jaw plastic surgery. In 1957, Obwegeser’s sagittal splitting osteotomy of the ascending mandible, and McCarthy’s traction osteotomy of the jaws in 1992. In China, Wu Tingchun first reported the surgical correction of mandibular protrusion in 1959. The early maxillofacial surgery only corrected the skeletal deformity, and could not solve the malocclusion disorder caused by the jaw deformity. With the demand of continuous progress of various disciplines, many advanced techniques have been born in addition to the formed conventional surgery, and the interdisciplinary collaboration and joint development has become an important development direction for the correction of maxillofacial deformity. First, the modern conventional orthognathic surgery and plastic surgery Modern orthognathic surgery is a combination of medicine and aesthetics of the edge of the discipline, it is the application of oral and maxillofacial surgery and orthodontic methods of joint correction of deformity, restore function, alter the tissue structure, so that patients get a beautiful appearance and teeth alignment of the treatment effect. China is from the 1980s, after a few 10 years of development and improvement, orthognathic surgery has formed a complete set of treatment procedures, from preoperative diagnosis, determine the treatment plan, preoperative orthodontic treatment, model surgery, surgical correction, postoperative orthodontic and other links. After generations of exploration, practice and improvement, the standardized orthognathic surgical procedures have matured, including Le Fort I osteotomy, ascending sagittal split osteotomy, horizontal osteotomy chinplasty, strong internal fixation after osteotomy and a series of orthognathic surgical techniques have formed a standardized operation procedure. Most of the oral and maxillofacial deformities can be solved by maxillary LeFort I osteotomy and bilateral ascending sagittal splitting osteotomy assisted chinplasty, so these procedures have become the classic orthognathic surgical procedures with a wide range of indications. And the application of some tissue substitutes in plastic surgery, such as porous polyethylene, expanded polytetrafluoroethylene, fluorinated ethylene propylene, etc., both good tissue compatibility, good forming effect, but also reduce the surgical trauma, from another angle for the maxillofacial deformity correction provides a useful supplement. Distraction osteogenesis The maxillofacial distraction osteogenesis technique (distraction osteogenesis) is a new technique developed in the 1990s based on the traction lengthening technique for long limb bones. The principle is to use a specific device to apply a continuous slow force to the amputated bone segment, which induces a simultaneous regeneration of bone tissue and surrounding soft tissue, resulting in the formation of new bone in the gap between the distracted bone segments and the simultaneous growth of the surrounding bone tissue. The emergence and application of this technique has opened up new ideas and avenues for the treatment of many complex dental and maxillofacial malformations that are difficult to treat with conventional clinical techniques. Not only can severe skeletal deformities be corrected, but also the accompanying various soft tissues (muscles, blood vessels, nerves, skin, etc.) can be lengthened. With a series of advantages such as significantly reduced surgical trauma, reduced surgical complications, and improved postoperative stability compared to conventional surgery, this technique has rapidly become a hot spot of concern for maxillofacial and plastic surgeons around the world, and a large number of research papers have been coming out. This technique is mainly used in the treatment of severe jaw deformities, such as severe maxillary hypoplasia, cleft lip and palate secondary to maxillary and mid-facial hypoplasia, severe micromaxillary deformity due to joint ankylosis, hemifacial hypoplasia, jaw defects and other deformities. However, there are some drawbacks, such as long treatment course, requiring phase II surgery, the relationship between upper and lower jaw cannot be well controlled during retraction, extra-oral retractors inevitably leave scarring on the face, intra-oral retractors increase the chance of infection, and the existing retractors are uniaxial retractors, which cannot fully solve the deformity of jaws in all directions, so further development of small, multi-axial, more flexible, easy to adjust, personalized Even the absorbable extender is a direction for the continued development of the technology. Third, strong internal fixation technology The successful application of this technology in the international arena began in the early 1990s. Although China started late, but the progress is rapid, standardized maxillary and mandibular osteotomy after the use of strong internal fixation technology in many hospitals has become routine. The strong internal fixation technique not only greatly simplifies the intraoperative operation procedure, reduces the risk and pain of postoperative intermaxillary ligation, and improves the postoperative quality of life of patients; the fixation according to the main stress trajectory is more in line with the biomechanical characteristics of the jaw bone, improves postoperative stability and reduces postoperative complications, which is welcomed by patients. This has also become a symbol of China’s international integration. In recent years, foreign countries have developed absorbable fixation plates and nails, and some clinical applications have been reported, but they are not yet popular. Pre-operative and post-operative orthodontic techniques Most of the maxillofacial deformities are accompanied by the dental relationship and the functional abnormalities of the oral and maxillofacial system, the perfect maxillofacial deformities should be pre-operative and post-operative orthodontic treatment personnel, so that patients not only have the improvement of appearance and dental relationship to achieve good dental standard, this work in China is now gradually popularized in provincial and municipal hospitals, which is the treatment of such diseases in China to achieve a comprehensive and This is another sign that the surgical treatment of these diseases in China has achieved full compliance with international standards and has reached the orthodontic level of developed countries in the world. Unlike traditional orthodontics, orthodontics before and after jaw surgery for malocclusion both belongs to the category of adult orthodontic treatment and is different from general adult orthodontics. The goal of orthodontic treatment is to achieve a better postoperative dental relationship, increase postoperative jaw stability, and reduce unnecessary intraoperative osteotomies by the maxillofacial surgeon. With the wide development of minimally invasive techniques in the field of surgery, some scholars have also introduced the concept of minimally invasive surgery into the surgical treatment of various skeletal deformities of the jaws. In 1994, Bostwick [8] first reported the sensation of endoscopic Le Fort III osteotomy in adults, and in 1995, Kobayashi et al [9] reported that the endoscopic osteotomy was performed via the scalp with a small median incision and nasal root. In 1995, Kobayashi et al [9] reported three cases of whole nasal frame osteotomy and two cases of modified Le Fort II nasal frontal joint osteotomy successfully performed under endoscopy through small median incisions and incisions at the root of the nose and between the nasal cartilages, with results that did not differ from those of open surgery. In 2001, Rohner and Yeow et al. performed minimally invasive Le Fort I osteotomy in 2 patients with cleft lip and palate secondary to maxillary hypoplasia using endoscopic technique, with anterior displacement of the maxilla by 5-7 mm. the operative time was 1h30min. postoperative swelling was slight and the wound healed well. Troulis et al [11] selected 1 patient each with mandibular protrusion, deviation and mandibular asymmetry. Wiltfang et al. reported minimally invasive surgery-assisted traction osteogenesis in two patients with maxillary hypoplasia treated with transverse sphincter arch with good results, and concluded that minimally invasive surgery-assisted traction combines the advantages of both traction osteogenesis and minimally invasive surgery and can more effectively release the deformity. In recent years, with the prevalence of facial contour remodeling, many scholars at home and abroad have applied endoscopic techniques to facial contour remodeling for mandibular angle and high zygomatic bone reshaping. Minimally invasive surgery in maxillofacial deformity revision is still in its infancy, with the development of three-dimensional CT, navigation surgical system, the joint use of other new technologies, can make it a routine surgical operation for patients. Sixth, computer and three-dimensional navigation technology Thanks to the rapid development of information science and life sciences and cross-penetration between disciplines, computer-aided surgery technology (computer aided surgery, CAS) using modern digital imaging technology such as CT, MRI, PET obtained by multi-mode image data, through computer processing and analysis, the precise design of surgical plans Altobelli, Evertt and others have created a three-dimensional surgical simulation system to realize three-dimensional visualization of craniomaxillofacial soft and hard tissues and surgical simulation of interactive osteotomy. . In other words, the virtual surgical osteotomy instruments can be used in the virtual three-dimensional space to cut and quantitatively move or rotate the bone blocks to simulate deformity correction. At this stage, the more representative and influential craniomaxillofacial CAS system is Julius developed by the German caesar research center and Amira developed by ZIB laboratory. similar results have been reported by Sun Yingming et al. in China. Hassfeld et al [18] reported several cases of navigation-guided completion of maxillofacial osteotomy, which obtained incomparable surgical results in the past. VII. Microsurgical techniques Although many jaw deformities can be satisfactorily corrected by traditional orthognathic surgical means or plastic means, there are still some jaw deformities due to long-term functional factors or other factors that cause underdevelopment of soft tissues, such as progressive unilateral facial atrophy, where such patients not only have short deformities of half of the jaws, but also have significant atrophy of half of the facial soft tissues, for which severe For the surgical correction of this severe facial asymmetry, simple osteoplasty cannot completely restore a symmetrical facial shape. Some scholars advocate a phased approach to surgery, with surgical correction of the maxillary and mandibular deformities completed first, followed by a phase II soft tissue revision to restore the facial shape, usually after 6 months. In the past, the commonly used methods included free grafting of the greater omentum or anastomotic vessels, or free grafting of dermal fat, but the results were poor due to a greater degree of postoperative absorption of the grafted tissue. At present, the method of free grafting of composite scapular flap with vascular tip or other vascularized musculocutaneous flap is mostly used, which has the advantages of completion at one time, taking into account the repair of subcutaneous tissue and skin tissue, high survival rate, less absorption and atrophy. In cases with red lip atrophy, a tipped tongue flap graft can be used with good results. There are also many reports from abroad on the repair of soft tissues for such disorders. In fact, after years of practical development in various disciplines, people gradually realize that a complete plastic treatment of maxillofacial deformities should be an organic combination of plastic surgery, oral and maxillofacial surgery and orthodontics. The collaboration between the various disciplines to complement each other’s strengths is essential for the treatment of these disorders.