The treatment of congenital microtia mainly includes two aspects, one is the reconstruction of external ear and the other is the reconstruction of hearing function. Generally, the external ear is reconstructed first, and then the auditory function is reconstructed. Hearing reconstruction often destroys the skin behind the ear and should be carried out after auricle reconstruction. Normal auricle reconstruction is composed of thin skin and soft tissue wrapped by elastic cartilage scaffold, which has an elastic thin shell structure and consists of helix, tragus, helix, earlobe, external ear, triangular fossa and navicular fossa. The shape is complex, so auricle reconstruction is a difficult and complicated operation. Although the reconstructed ear with normal auricle shape can be made at present, there are many factors that affect the shape of the reconstructed ear. The elasticity, thickness and size of the skin behind the residual ear and the length, shape and thickness of the costal cartilage used are very different. These conditions will affect the effect of the operation, and the scar composition of individual patients will also affect the shape of the reconstructed ear. Therefore, patients who require auricle reconstruction can understand the difficulty of the operation and take a realistic attitude towards the results before they can carry out auricle reconstruction, otherwise they should be cautious. Old and infirm people should wear artificial ears, and ear reconstruction is not suitable. 1. Timing of operation The timing of ear reconstruction is very important, which is one of the main determinants to obtain ideal surgical results. We think that 9 years old, 10 years old and1/kloc-0 years old are the best age for ear reconstruction. Too young, because its autogenous costal cartilage is small, thin and soft, it affects the fabrication of auricular cartilage scaffold, thus affecting the final surgical effect. Moreover, premature surgery requires more costal cartilage to be removed, and the probability and degree of thoracic deformation are higher and heavier when a costal cartilage is loaded than when a cartilage is older. However, it is best to complete the external ear reconstruction operation before puberty, because the psychological changes of adolescent children are great, and the impact on their psychological development before puberty will be much smaller. Although we have solved the technology of ear reconstruction for elderly patients, it is best not to wait until we are too old. With the increase of age, the texture of costal cartilage will change, even become yellow and brittle, which increases the difficulty of making auricular cartilage scaffold. 2, reconstruction methods Ear reconstruction usually requires 2 to 3 operations. There are two specific methods. One method is called Brent method. Brent is an American doctor. Later, Dr. Nagata of Japan made great technical improvements. This method is the most widely used and common method in the world. This method does not require skin expansion. This method usually has two operations. In the first operation, the costal cartilage was taken and the ear bracket carved from costal cartilage was directly implanted under the skin behind the ear. Ear reconstruction surgery is the most important thing this time. The second operation pricked up the ears. If you do it for the third time, you can make it more beautiful. Each operation takes about 10 days, and the interval between operations is 4-6 months. The ear made by this method is thin, the outline is clear, the surgical scar is small, the method is simple, safe, the treatment time is short, and the patient's pain is small. This method is suitable for patients with rich deformed ear skin, loose skin behind deformed ear and large area, and we prefer this method for patients in this situation. The other is skin expansion, and the operation usually takes 3 times. In the first operation, 50 ~ 80 ml water sac (skin and soft tissue expander) was implanted in the mastoid region of the residual ear, and the hospitalization time was about 4 days. Seven days after operation, normal saline was injected every other day, and it took about 1 month to fill it with 50 ~ 80 ml normal saline. After the water injection, he rested for 1 month, and then came to the hospital for a second operation. The second operation took out the dilator, cut it from the costal cartilage of the body, carved the ear bracket according to the size of the healthy ear to rebuild the auricle, and the hospitalization time was about 10 days. Some patients can further repair the reconstructed ear 3 ~ 6 months after the second operation, and the hospitalization time is about 7 ~ 10 days. Although this method takes a long time to treat and causes great pain to patients, it is best to choose the method of skin expansion for patients with small and thick skin behind ears. The key to the choice of ear reconstruction method is the patient's own conditions, and the method suitable for the patient is the one that can get the best effect. Hearing reconstruction Most patients with congenital microtia have atresia of external auditory canal. When parents take their children to see a doctor, they are often most concerned about hearing, thinking that the child's ear is completely deaf, or a hole in the skin can completely restore hearing. In this regard, doctors should explain hearing problems from the embryonic development of ears and correct their misconceptions. During embryonic development, the middle ear and external ear mainly come from the first and second branchial arches. At 5-week-old embryo, the auricle appears in the form of six hills on these two branchial arches, while the inner ear appears at 3-week-old embryo, and the inner ear comes from ectodermal tissue. Due to different tissue sources, patients with microtia are mainly developmental malformations of the outer ear and middle ear, and the inner ear is often not involved. There are two ways for sound to reach people's inner ear. The way from the outer ear to the middle ear and then to the inner ear is called air conduction, and microtia has air conduction disorder. The transmission of sound from the skull to the inner ear is called bone conduction. The bone conduction of microtia exists, and it can also be heard for loud sounds. Generally speaking, the hearing of the affected side of unilateral microtia is about 40%, and the hearing of the healthy side is normal, which has little influence on language pronunciation and daily life except for poor judgment direction. Therefore, it has been controversial whether such patients should undergo external auditory canal plasty to improve their hearing. The main objection is that there are many surgical complications, and the improvement of their hearing is very small and often not lasting. In recent years, with the development of technology, otologists tend to operate. There are also differences between otologists and plastic surgeons in the order of surgery. The lack of elasticity of reconstructed ear will affect the operation of otologists, but the skin in mastoid region often leaves scars after external auditory canal surgery, which affects plastic surgeons to make full use of this skin for auricle reconstruction. However, as long as the position of the reconstructed ear is preserved, experienced otologists can also carry out hearing reconstruction after auricle reconstruction. Hearing surgery needs the development of mastoid air cavity in order to have enough space to form external auditory canal. When the mastoid cavity is underdeveloped, the external auditory canal is difficult to form, because the temporomandibular joint in front cannot be changed, the upper tympanum is very low, the sigmoid sinus in the back moves forward, and the facial nerve is below. Under normal circumstances, there is almost no passage for the external auditory canal formed by mastoid to enter the middle ear cavity, so ear canal plasty is not suitable for those with underdeveloped air chambers; On the other hand, for those with well-developed air cavity, although external auditory meatus plasty can be used to improve their hearing, the author believes that autologous fascia used to reconstruct tympanic membrane is not a tissue transplant, but a biological dressing to help heal, which is prone to complicated situations such as infection and bleeding after operation. External auditory canal is formed on the basis of removing part of mastoid bone and air chamber, and patients are prone to form fistula after tympanoplasty. At the beginning of the operation, the grafted skin grew well on the bone surface, and the surface of the ear canal gradually became flat and smooth. However, with the contraction of the skin graft, the mucosa of the middle ear cavity or the residual mastoid air cavity will grow into the ear canal. Exposure of mucous membrane to air will cause chronic and lasting secretion, stimulate surrounding tissues and cause chronic inflammation, and produce pus whenever patients catch a cold. Once this happens, it is quite difficult to deal with it. Under normal physiological conditions, the liquid in the mastoid air chamber is discharged through the eustachian tube. The interference of operation changes this normal flow direction, and the fistula makes it flow back into the ear canal. Therefore, such an operation is not physiological in a sense, but turns a dry ear into a wet ear. The methods to prevent this complication are as follows: the external auditory canal is as wide as possible, close to the cavity formed during radical mastoidectomy, the mucosa of the middle ear cavity is kept intact during operation, the drainage system of mastoid-eustachian tube is not affected, and the ear canal wall is covered with skin flap as much as possible. However, it is very difficult to complete these tasks completely. Too wide ear canal not only looks ugly, but also affects auricle reconstruction. Therefore, although it is attractive for patients to recover their hearing, for patients with unilateral microtia and normal hearing on the healthy side, it is necessary to weigh the possible postoperative infection, the trouble of frequent dandruff removal in ear canal reconstruction and the limitation of some sports such as swimming. Whether it is worth doing middle ear surgery at the same time to improve hearing is not ideal at present and should be carefully considered. In short, for patients with bilateral microtia and atresia of external auditory canal, external auditory canal plasty can be considered to improve hearing. However, for patients with unilateral microtia, the author's experience is to perform partial external auditory canal plasty with a depth of about 1cm, without entering the middle ear cavity, and try to cover it with an inward-turned local flap. The flow direction from mastoid to eustachian tube is basically unchanged, so there are no complications such as infection and bleeding after operation. In this way, although the patient did not improve his hearing, he was psychologically satisfied because of the structure of "ear canal" behind the tragus, and the appearance of the reconstructed ear was more complete. Auricular reconstruction and correction of cervical malformation Patients with congenital microtia are often accompanied by asymmetric facial development and short affected side. Most patients first require ear reconstruction, and even some patients with serious facial deformities are often hospitalized for ear reconstruction. In patients with mild facial asymmetry, there is no significant difference in vision after auricle reconstruction, and maxillofacial plastic surgery is generally not needed. In severe cases, besides microtia, the developmental deformity of mandible (mainly mandibular branch) is also obvious. The mandibular branch of the affected side is often short and biased to the inside, and even missing in severe cases. The mandibular body bends towards the short lower collar branch, and the chin is on the affected side. The median sagittal line of the face is inconsistent with that of the lower collar. This deformity of mandible is not manifested in the same plane, but in three-dimensional space. Due to the unbalanced growth between the healthy side and the affected side of mandible, facial asymmetry becomes more and more serious with the development of children, and it is generally believed that it will stop in adulthood. The three-dimensional spatial changes of mandibular deformity have more complicated time factors. In addition to the congenital possibility of maxillary dysplasia, its normal downward growth will also be hindered by mandibular dysplasia. The dysplasia of maxilla, mandible and its alveolar process can lead to the inclination of dentofacial surface and the opening of healthy side. For such patients, orthodontic or surgical treatment should be carried out according to their age and jaw deformity to restore their normal function and appearance. The commonly used methods in the past, such as bone transplantation, are complicated in operation and have unsatisfactory results. MC-Carthy et al. have been using bone extender to gradually lengthen mandible since 1989, and think that this method saves the steps of bone implantation and intermaxillary fixation in craniofacial plastic surgery. Although this method takes a long time, it will not increase the time simultaneously with auricle reconstruction through skin expansion. As for the dysplasia of maxilla and local soft tissues, normal mandibular movement should promote the development of maxilla and surrounding soft tissues after mandibular lengthening in childhood, and the relationship between maxilla will be gradually corrected naturally. Therefore, although the operation only lengthened the mandible, it gained the benefits of three-dimensional space change. There are two kinds of mandibular extenders: extraoral bone extenders and intraoral bone extenders. The intraoral bone extender is more ideal, but it has more complications than the former. Mandibular lengthening is generally only suitable for children before 12 years old, while auricle reconstruction is over 6 years old. Therefore, the operative age of auricular reconstruction and mandibular lengthening is 6- 12 years old. The specific operation steps are as follows: auricle reconstruction was performed by skin expansion method, and 50ml renal dilator was used. Mandibular lengthening was performed with a small stainless steel extraoral bone extender. The operation is divided into three stages: the first stage: bone extender and dilator are inserted. The operation was performed under general anesthesia. After operation, the suture was removed 1 week, and the expansion was started by water injection on the third day, which was completed in about 30 days. Turn the screw of the extender to extend the clavicle by about 1 mm every day until the designed length is reached. Second stage: auricle reconstruction second stage: take out the skin expander 2-3 months after skin expansion for second stage auricle reconstruction. The second stage: take out the dilator after 4-6 months, and reconstruct the auricle in the third stage.