Progressive hemifacial atrophy (progresivehemificialarophy) is an acquired facial deformity characterized by progressive unilateral atrophy of the skin, subcutaneous tissues and bone structures. The lesion mainly involves the hemifacial tissues and in mild cases results in sunken cheeks and bilateral facial asymmetry. In severe cases, the upper and lower jaws are underdeveloped, the eyes are sunken, and vision is diminished or blinded, resulting in severe facial disfigurement. In the past 10 years, we have treated more than 100 patients, and through a large number of clinical cases, we have accumulated rich clinical experience for different degrees of deformities, proposed our own clinical classification method, and formed our own treatment concept and characteristics. According to the severity of hemifacial atrophy, the hemifacial atrophy deformity is divided into: 1, mild: local soft tissue atrophy of the affected cheek, basic symmetry of the overall facial contour, no obvious involvement of the nose and lips, no obvious angle of mouth tilt. 2.Moderate: large atrophy of facial soft tissues, forming a clear division with the healthy side, atrophy of the nose, atrophy of the upper lip on the affected side, skewing of the mouth angle to the affected side, and involvement of facial bones. 3.Severe: severe atrophy of facial soft tissues, severe dysplasia of deep bones, accompanied by skewing of the chin and tilting of the jaw plane. Treatment principles Bilateral asymmetrical deformities of the craniomaxillofacial region caused by hemifacial atrophy are a group of deformities that are common and difficult to treat clinically, with varying degrees of severity, involving the treatment of soft and bone tissues. The etiology and pathogenesis of this deformity are still unclear, and there is no effective treatment to stop or reduce the development of the deformity for patients in the progressive stage, and only surgical treatment can be used after the development of the disease has stopped. We need to design a personalized surgical plan according to the patient’s specific situation, and use a combination of plastic and craniomaxillofacial surgical techniques to reconstruct in stages. If the skeletal deformity is not obvious but mainly soft tissue atrophy and depression, tissue transplantation can be used to fill and repair the deformity. For patients with craniofacial skeletal dysplasia, the reconstruction of facial skeletal scaffolds should be emphasized. For patients with severe hemifacial atrophy and obvious soft tissue atrophy, the blood supply of local bone tissue and soft tissue is poor, so the soft tissue coverage problem should be solved first, and then bone tissue reconstruction should be considered in stage II. Good soft tissue coverage is a prerequisite for successful bone reconstruction. Surgical methods 1. Soft tissue reconstruction: (1) Mild to moderate facial soft tissue atrophy and depression – use autologous fat particles to fill in by injection. (2) Localized depression of autologous fat particles cannot be filled by sub-injection – autologous dermal graft is used for filling. (3) Severe facial soft tissue atrophy – free tissue grafting with anastomotic vessels. The depressed face can be filled with anterolateral femoral fascial fat flap or scapular dermal fat flap graft, and the contour will be trimmed after 3-6 months. 2, facial bone reconstruction according to the degree of bone involvement, the following methods can be used to rebuild: (1) mild zygomatic and mandibular dysplasia, the occlusal relationship is basically normal: the affected side of the zygomatic bone and mandible bone implants, increase the degree of zygomatic protrusion and the width of the mandible. Osteotomy of the chin can be used to correct the skewed chin deformity. (2) Maxillary and mandibular dysplasia with occlusal plane tilt: maxillary LeFort I osteotomy rotation, mandibular sagittal split osteotomy rotation and chin osteotomy displacement, patients with severe occlusal plane tilt, simultaneous maxillary LeFort I osteotomy and mandibular sagittal split osteotomy rotation to correct jaw plane deviation is often difficult, such patients are best first mandibular ascending branch and body retraction extension to correct In such patients, it is better to perform mandibular ascending branch and body distraction lengthening first to correct the mandibular deformity, and then perform maxillary LeFortI osteotomy rotation and descent in stage II to correct the open jaw on the affected side. In conclusion, the treatment of severe hemifacial atrophy is still one of the difficult problems in plastic surgery, mainly because of the difficulty of surgery, the number of operations and the unsatisfactory results. Atrophy of the nasal flank, the angular deviation of the mouth caused by the shortening of the upper lip, and the inversion of the eye caused by the atrophy of the orbital contents are the most difficult to treat.