The face is an important cosmetic and functional unit of the human being, and the trauma and scarring left after burns, trauma, and tumor resection not only affects appearance, but also the function of the eyes, ears, nose, and other organs. Traditional plastic surgery techniques – skin grafting, local flap and flap transfer – have their own limitations in facial repair and reconstruction, and since the application of skin soft tissue expansion, it has provided a new way of thinking for the repair of scar. 1, surgical operation Dilator placement (stage I surgery): according to the diseased area and lesions to design the incision and choose the shape and size of the implanted dilator. If the facial scar is large, and there is no local available tissue or the neck scar contracture deformity is heavy, the dilator (400-500ml) is usually buried in the chest, and the chest triangle flap or transverse cervical artery cervical segmental flap is applied to repair the scar. When the expander is implanted in the face, it is embedded in the superficial surface of the parotid occlusal fascia (SMAS); when the expander is implanted in the neck, it is implanted in the superficial layer of the cervical latissimus dorsi muscle for obese patients, and it is implanted in the subluxation layer of the cervical latissimus dorsi muscle for thin patients. In the chest, the dilator was placed according to the proposed repair method. For those who intended to use the thoracic triangle flap, the dilator was implanted on the surface of the myofascia with the line between the second intercostal space and the acromion as the axis; for those who intended to use the flap of the cervical segment of the transverse cervical artery, the dilator was implanted in an outwardly downwardly directed flap, with the level of implantation also being the surface of the myofascia, with the axis of the midclavicular point. When stripping the lumen is slightly larger than the periphery of the expander 0.5 – 1.0 cm, immediately after the expansion period is placed into the appropriate amount of saline, layered suture incision, postoperative 4 – 7 days of injection of water, the amount of water injection to the degree of vasodilatation of the flap and the color of the flap as an indicator of the change in the flap. The amount of water injected is based on the degree of vascular expansion of the flap and the change of flap color. Expansion flap transfer repair (stage II surgery): in general, when the expansion area reaches more than two times of the defect area, stage II surgery can be carried out, with scar excision and flap transfer. The design of the incision should take into account both the full extension of the expanded flap and the concealment of the incision after transfer in order to obtain good cosmetic results. For those who have buried expanders around the scar, according to the different parts and defects, advancement flaps, rotational flaps, and staggered flaps (translocation flaps) can be used to repair the defects. If the facial scar is large and there is no local available tissue, a thoracic triangular flap with the 2nd and 3rd intercostal branches of the internal thoracic artery as the tip is used for repair; if the neck scar is contracted, a transverse carotid artery cervical segmental flap is used for repair. In order to achieve the best results, retrograde design is important in face and neck repair. Otherwise, the size of the flap is not enough or the extension length is not enough, which is easy to cause the pulling deformity of the eyelid, the corner of the mouth and the upper lip; or the neck trauma is too large to be closed in one stage or need to carry out supplementary implantation. 2, the results of this group of 54 cases of 102 dilators, the occurrence of hematoma occurred in 2 cases, infection and incision exposure of 1 case each, all the complications after timely symptomatic treatment did not affect the surgical results. Follow-up 6 – 36 months, the appearance of color and elasticity is good, face, neck and chest activities are normal, 48 patients were satisfied, 6 patients complained that the incision scar hyperplasia is obvious, half a year later, scar excision suture surgery, postoperative results are satisfactory. 3, Discussion 3.1 Since Radovan physicians began to apply skin soft tissue expansion in 1976, due to the color, texture, and structure of the expanded tissue to match the recipient area, expansion has rapidly become one of the main means of tissue repair by plastic surgeons. However, its use has been somewhat limited due to its high complications such as infection, hematoma, and exposure. In order to reduce the complications, we carefully consider every detail before, during and after the operation to effectively reduce the occurrence of various complications. 3.1.1 In the preoperative period, according to the site of repair, the scope and shape of the lesion, and the size and shape of the normal skin available for expansion to select the dilator, decide the site and direction of burial, but also to pre-consider the proposed flap in the second stage of repair, the convenience of the flap transfer, and the second stage of the postoperative incision of the concealment and minimization. For example, for a relatively large round scar, we often bury the expander in two symmetrical directions, and the final repair is like an “O-Z” flap, which can effectively apply the expanded tissue and minimize the secondary incision. 3.1.2 For the face and neck, the greatest complication of dilator placement is hematoma. Many infectious complications are also secondary to hematoma, in order to effectively control hematoma, we mostly use endoscopy for thorough hemostasis, and small oozing blood is not spared; in addition, after the peeling of the dilatation capsule is completed, we usually do not hasten to implant the dilator, but fill in the wet gauze with warm saline, observe for half an hour, and hemostasis is performed again. This is due to the fact that during the stripping process, many broken blood vessels undergo spasm; coupled with the fact that in order to minimize bleeding during the stripping process, a certain amount of adrenaline is usually applied, which causes many small blood vessels to constrict, and do not bleed in the early stages, but bleed secondary to bleeding in the later stages. These vessels have a greater chance of causing hematomas if not electrocoagulated or ligated. In the face buried dilator, must pay attention to the zygomatic ligament there is a blood vessel from the deep to the skin of the blood vessels, if this branch is cut and not ligated, it is very easy to occur hematoma, this group of two cases of hematoma are caused by this. Expander incision exposure is ranked second in many literatures, in order to prevent incision exposure, we have made some improvements in the suture method and incision direction. When conditions permit, we usually use an incision perpendicular to the long axis of the dilator; for incisions parallel to the dilator, we first fix the flap to the deep tissue at about 0.5-1 cm from the incision during suturing, which can effectively reduce the tension of the incision after dilatation with water. 3.1.3 For the dilatation method, we mostly use the conventional dilatation method. Because the “extra” tissue obtained by too fast expansion is not obtained by tissue proliferation, but by elastic expansion and peristalsis of the surrounding tissues, the postoperative retraction is more serious, and the late effect is not good; in addition, too fast expansion is likely to lead to the appearance of the flap with “stretch marks” like changes, and the appearance is not good. In addition, too rapid expansion can easily lead to “stretch marks” on the skin flap, and the appearance is not good. 3.1.4 Since the face is an aesthetic organ, when expanding the flap for transfer, it is necessary to consider whether the suture opening after transfer is concealed and conforms to the aesthetic point of view. Also whether the flap transfer will cause secondary pulling deformities on the eyes, lips and other organs. In order to minimize secondary pulling complications after flap transfer, the expansion flap must be large, and flap retraction should be taken into account. In general, a flap larger than 10% – 30% of the repair area is preferred. For second stage surgery, it is important to utilize the flap effectively as well as to obtain the ideal result, the retrograde design is very important. If inexperienced, never dare to blindly make an incision, in the flap cut, try to transfer and then based on the repair area of the flap to excise the lesion and scar. 3.2 Application of axial flap pre-expansion: When the scar area of the face and neck is large or the contracture is more serious, there is often no local tissue available for expansion, and the application of distal or neighboring axial flap pre-expansion and then transfer is a more effective method. Since the flap is preexpanded and then retransferred, it increases the surgical time and surgical difficulty, so it is more important to pay attention to every detail during the surgery to minimize complications. The preexpansion area of both the thoracic triangle flap and the transverse carotid artery cervical segmental flap is in the anterior thorax, and a 400-600 ml expander is usually embedded. Because the anastomotic network of the major vessels in the thoracic triangle is in the superficial layer of the deep fascia, in order to avoid damage to the anastomotic branches of the vessels, the dilatation space should be peeled off at a level below the deep fascia to prevent hemodynamic obstruction when forming a larger flap. When separating to the proximal tip, it is important not to peel sharply in order to avoid injury to the intercostal perforating branch of the internal thoracic artery or the cervical segmental cutaneous branch of the transverse carotid artery. In addition, the delayed technique is applied flexibly in order to ensure the blood flow of the flap. For example, if a thoracic triangular flap is to be applied, the descending branches of the thoracic acromioclavicular artery and the carotid branch of the transverse carotid artery are ligated when the dilator is embedded, so that the blood supply of the dilated flap is dominated by the second and third intercostal perforating branches of the internal thoracic artery, which plays a delayed role. In the case of the proposed transverse carotid artery cervical segmental flap, the second and third intercostal branches of the internal thoracic artery and the thoracic acromioclavicular artery were ligated at the time of dilator placement. Also a delayed procedure should be performed first if it is necessary to carry the flap tip to repair jaw or chin scarring when the tip is broken. After the flap is transferred with the tip, in order to prevent the pulling and twisting of the flap tip, we tend to fix it with a plaster cast so that the neck is in a forced position, which is favorable for the tip to remain in a relaxed state. In order to facilitate the smooth progress of tip breakage, we start tip breakage training at 7 days after surgery, and usually break the tip at 21 days.