Progressive hemifacial atrophy, also known as Romberg’s disease or Parry-Romberg syndrome, was first reported by Parry in 1825 and described in detail by Romberg and Henoch in 1846, whose main clinical manifestation is atrophy of the skin, subcutaneous tissue and muscles on one side of the face bounded by the midline. Partial loss of occlusal function. The traditional classical treatment mainly focuses on the restoration of soft tissue volume, including: fat, dermis, vascularized dermal fat flap free transplantation or allogeneic material filling, while often neglecting the reconstruction of the skeletal structure, so the treatment effect is not very satisfactory. 1. The treatment plan mainly focuses on the patient’s deformity, and the corresponding surgical plan is designed to reconstruct the shape and function of the affected side. For those who do not have obvious skeletal deformity but mainly show soft tissue atrophy and depression, tissue transplantation and other means can be used to fill in the repair; for those who also have severe craniofacial skeletal dysplasia, the skeletal scaffold of the face should be reconstructed first to improve the facial morphology, and further improve the contour with the necessary soft tissue surgery. 2.1 Reconstruction of facial skeletal contour hemifacial atrophy skeletal deformity mostly involves the affected zygomatic bone and maxilla, manifesting as obvious concavity of the zygomatic maxilla, and in severe cases, obvious maxillary dysplasia, shortening of the maxillary longitudinal length, tilting of the occlusal surface to the affected side, causing open bite on the affected side and affecting masticatory function. Hypoplasia of the lower jaw leads to a narrow mandibular body and a skewed chin. According to the deformity of the bones, the face as a whole is contoured and osteotomy displacement or bone filling implants are used to reconstruct the anatomical scaffold of the face and increase the local bone volume. 2.1.1 Autologous bone or Medpor implantation for zygomatic bone augmentation and mandibular angle body widening Preoperatively, the site and thickness to be grafted are analyzed by cranial 3D CT reconstruction, and an intraoral incision is used to reveal the anterior wall of the maxilla and the zygomatic body, or the mandibular body and angle area. The autologous mandibular outer plate, iliac bone or Medpor prosthesis is trimmed to the appropriate size and shape, placed at the preoperatively designed site, and fixed with two to three titanium nails. 2.1.2 Orthognathic surgery, for patients who are relatively limited to severe maxillary atrophy, there may be open jaw, hemifacial anterior and posterior retrusion, the damaged maxilla is displaced forward and downward through maxillary Le Fort I osteotomy to restore the patient’s normal occlusal relationship, while free bone grafting is applied to the anterior wall of the maxilla and the osteotomy gap by applying autologous bone, which serves to correct the atrophy of the maxillary body, fix the broken ends of the bone and It can improve the appearance and increase the stability of the bone segment. For patients with severe atrophic deformities of the upper and lower jaws and facial soft tissues, along with a deviated occlusal plane, bimaxillary surgery can be performed, including sagittal or vertical splitting of the mandibular ascending branch and maxillary Le Fort I osteotomy. In patients with significant reduction in mandibular volume and severe soft tissue atrophy on the affected side, the sagittal splitting of the mandible often does not allow complete descent and accurate rotational advancement of the bone segment due to high soft tissue tension, and the recurrence rate is also high. The application of mandibular lengthening can be considered for simultaneous lengthening of the ascending mandible or body and soft tissues to first correct the deviation of the mandibular occlusal plane and cause open dentition on the affected side. The lengthening device is fixed for 3-6 months and then removed. While removing the lengthening device, a second-stage maxillary Le Fort I osteotomy is performed according to the patient’s occlusal relationship to restore its normal occlusal relationship and position, and if necessary, the teeth can be adjusted with postoperative orthodontics. For patients with hypertrophy of the mandible on the healthy side, the outer plate of the mandible on the healthy side can also be removed, which can improve the asymmetric deformity of the face and be used as a material for filling the mandible on the affected side, as well as provide a bone source for bone grafting in the bone gap of maxillary Le fort I osteotomy. The chin of these patients is often asymmetrical, short and receding, and overall skewed, so most of them need to be adjusted with chinplasty for the necessary facial appearance. 2.2 Reconstruction of soft tissues According to the restoration of bone construction, the necessary soft tissue deformities are repaired for the patients, and the commonly used methods include the following 2.2.1 Autologous fat free graft filling This method can be used as the preferred method for soft tissue reconstruction of mild, moderate or even severe hemifacial atrophy. Before surgery, the patient is placed in a sitting position and the extent of atrophy is marked with US blue. The desired fat is extracted with a 2 mm diameter liposuction needle in the lower abdomen or anterolateral femur, centrifuged, 1000 r/min for 3 min (10 cm centrifugal radius), the upper layer of oil and the lower layer of hemorrhagic swelling fluid are removed, and the purified fat particles in the middle section are taken and set aside. According to the preoperative markings, the fat was pushed slowly and evenly in multiple directions and levels under the skin in the depressed area with a 2mm blunt-tipped liposuction needle, and gently massaged until the fat was evenly distributed. Due to the presence of absorption of autologous fat, 2 to 3 treatments are usually performed. 2.2.2 Vascularized fat flap free graft filling For severe hemifacial atrophy that cannot be filled with fat particles, vascularized free fat flap graft filling can be used, including anterolateral femoral fascia fat flap [3], scapular dermal fat flap, and also foreign scholars use vascularized large omental graft. We often use the anterolateral femoral fascial fat flap, which provides a large volume of tissue, has a long vascular tip, does not require intraoperative position changes, and is easy to manipulate. According to the classical surgical approach [3], a fascial fat flap is taken, and the vessels in the recipient area are mainly facial arteries and veins, but also the superior thyroid artery and external jugular vein can be used, and small skin islands can be prepared in order to observe the blood flow of the flap. Two to three half-tubes must be placed for postoperative drainage to prevent the formation of subcutaneous hematoma. The donor area can be directly closed with sutures. The biggest problem with the use of free fascial fat flap repair is soft tissue sagging in the long term, manifested by bulging of the lower face, downward pulling and displacement of the lower eyelid and external canthus, which often leads to repeat visits and requires multiple surgical revision and shaping to obtain partial improvement. achieve the desired facial shape. 2.2.3 Auxiliary surgery When facial autologous fat particles are injected and filled, the fat injected in the patient’s chin and lips is often significantly absorbed, leaving obvious local depression deformity, and even if repeatedly injected and filled, the effect is still poor, which may be related to the frequent activity of the lip muscles. We often choose autologous dermal folding graft for treatment. For patients with atrophic depression of the soft tissue of the affected upper lip, especially with red lip atrophy, the red lip defect can be repaired by cross-lip transplantation of the contralateral lower red lip. Angle of mouth deviation is the most difficult deformity to correct in soft tissue reconstruction, and its main cause is the shortening of the full-layer longitudinal soft tissue defect from the affected medial canthus to the angle of the mouth. To improve the angle of mouth deviation, a myocutaneous flap of the lower lip with the orbicularis oris muscle as the tip can be designed and transferred to the upper lip, similar to Z reshaping, to reduce the height of the affected angle of the mouth, paying attention to the design of the myocutaneous flap of the lower lip to be long enough. For those who also have white lip atrophy, overlapping autologous dermal implants can be used to fill in the same time. 3. Discussion: Soft tissue filling technique is still one of the most prominent treatments for patients with mild to moderate hemifacial atrophy. However, in severe atrophy, the bone tissue atrophy is also very severe with partial loss of function, so systematic reconstruction of soft tissue and skeletal structures is required. The skeletal changes include: ① Atrophic deformity of the zygomatic complex and maxilla, which can result in inferior displacement of the orbital bone, depressed deformity of the zygomatic complex, and upward and posterior displacement of the maxilla, accompanied by a lack of bone mass. ② Atrophy of the mandible, especially the ascending mandibular branch and, to a lesser extent, the corpora mandibularis, can lead to chin deviation and an inclination of the occlusal plane. Although the etiology of the soft and hard tissue atrophy caused by this disease is not clear, it is generally accepted that the earlier the onset, the more severe the bone tissue deformity. two cases were reported by Grippaudo et al. who gave orthodontic treatment to the patients during their adolescence, and the mandibles were basically symmetrical after the craniomaxillofacial development had matured and stabilized. This suggests that early orthodontic intervention can reduce the degree of atrophy of the skeletal structure or alleviate further distortion of the skeletal structure. Meanwhile, in the reconstruction of the skeletal structure, not only is it necessary to adjust the upper and lower jaws to achieve left-right symmetry to correct the inclination of the occlusal plane, but it is also necessary to increase the bone volume through bone grafting. For example, in Le Fort I osteotomy, due to the downward and anterolateral movement of the maxilla, autologous bone free grafts are needed in the segmental space or on the bone surface to promote segmental healing, enhance the stability of the segment, and increase bone volume. We found that some patients had good autologous bone survival and disappearance of the bone gap when the titanium plate and nail were removed at a later stage. In cases of maxillary deviation and mild mandibular atrophy, Le Fort I osteotomy can be performed alone, but in cases of severe mandibular atrophy and torsion, there is a need to lengthen and rotate the mandible, and the disease is characterized by atrophy of the soft tissues and high tension, and the sagittal splitting of the ascending branch of the mandible for anterior descent is greatly restricted, resulting in a restricted maxillary rotation as well, which is prone to recurrence after surgery. Therefore, we prefer to apply jaw lengtheners for mandibular ascending branch or body bone lengthening to increase the length of jaw bone and soft tissue while correcting the mandibular occlusal plane. In the second stage, the maxillary deformity is then corrected and the occlusal relationship is improved. Many scholars advocate a phase I simultaneous maxillary and mandibular lengthening to correct the jaw deformity to restore the occlusal relationship, but we prefer to complete the treatment in two phases of surgery, which can reduce the time of the patient’s intermaxillary ligature, and the patient can carry the lengthener home to recuperate after mandibular lengthening without affecting study and work, and then perform maxillary surgery, chin surgery and mandibular body widening after 3 to 6 months for skeletal contour reconstruction. In soft tissue reconstruction for mild patients, autologous fat injection is generally preferred. This method allows repeated operations without leaving defects in the donor area, avoids the complications of soft tissue sagging often encountered in doing fat flap free grafting, and also corrects the excessive area at the junction of the atrophy site and the normal site. In cases of severe soft tissue and bone tissue atrophy, often manifesting as “skin and bone”, according to our experience, for such patients, if bone reconstruction is performed first, normal postoperative healing of the jawbone is generally not guaranteed. Or choose the anterolateral femoral fascial fat flap with more fat volume, rich blood supply and long vascular tip for repair. We usually use Z-plasty and lower red lip cross-lip flap to repair the corners of the mouth and upper red lip tissue loss, and autologous dermal fold free graft to increase the amount of white lip tissue. Atrophy of the eyelid area is also one of the difficulties and can be repaired by brow suspension and transfer of the upper eyelid orbicularis muscle flap with a lateral tip to repair the lower eyelid.