The ear is an important organ among the five senses, responsible for the sense of hearing and body balance and, at the same time, has an important aesthetic role in the appearance and look of a person. The ear is usually medically divided into three parts: the outer ear, the middle ear and the inner ear. Each of these three parts has its own division of labor to perform its God-given functions, enabling humans to enjoy beautiful music and communicate effectively. Malformations of the ear will likely affect hearing and aesthetics. When an ear malformation occurs, malformations of the middle and inner ears cannot be seen but can seriously affect hearing, while malformations of the outer ear are not only easy to detect but may also affect hearing. This article discusses the medical issues related to outer and middle ear malformations and the issues that are of most concern to patients, with the aim of providing useful help and guidance to patients. I. What is microtia? Usually we classify microtia into 3 degrees; degree I is the least deformed ear, degree II is less deformed and looks like a small ear, and degree III is just a curly, salami-like tissue without any shadow of an earwax. The trouble is that microtia is often accompanied by atresia of the external auditory canal and middle ear deformity, because during embryonic development, the external ear and middle ear originate from the same germ layer. This is because the outer ear and middle ear originate from the same embryonic layer during embryonic development and often occur simultaneously. Although current research is inconclusive as to the cause of microtia, one thing that is certain is that it is not the fault of either parent and parents do not need to feel guilty. It is common for parents of children with microtia to feel guilty, but there is nothing they could have done to prevent their child’s microtia from occurring, and the parents are innocent. The probability of having a child with microtia in a normal couple is 1 in 5000-7000, however, if the parents of a child with microtia want to have a child again, the probability of having a child with microtia rises to 5%, or 1 in 20. 5% of the immediate family of a child with microtia has a family history of microtia, and the probability of a child with microtia having a child with microtia themselves is also 1 in 20. This is a problem that needs to be brought to the attention of parents, as prenatal screening is still difficult to detect microtia. Of course, most children with microtia do not have other malformations. About 1/3 of children with microtia have short hemifacial and 15% have facial nerve dysplasia. Other anomalies such as harelip, cardiovascular anomalies or urinary problems are not as likely. The children start to pay attention to their malformed auricles around the age of 3 to 3.5 years. They will compare their ears in front of a mirror and begin to refer to their “little ears”. When children are concerned about their little ears, parents should tell them that they are born with little ears and that when they grow up, doctors will let their little ears “grow up” and then treat them as completely normal children. This is mainly because family members are overly concerned about this matter and pass this concern on to the child. Can microtia be treated? There are many ways to treat and rehabilitate microtia, whether it is hearing loss or earwax deformity. The most common treatment methods are surgical reconstruction of the eardrum and hearing reconstruction. However, surgery for microtia is generally not recommended before 6 years of age because the child’s rib cage is not large enough to be sculpted into an ear scaffold in the size of the opposite normal ear until 6 years of age, and children are not particularly concerned about their abnormal ears until 6 years of age, so they do not suffer severe psychological trauma and are not very cooperative with post-operative care. They can actively cooperate with the surgeon during and after surgery. Microtia repair is a very challenging procedure in which the surgeon must sculpt the rib cartilage into a three-dimensional ear shape in an operating room setting in a limited amount of time, and then create a “pocket” under the skin where the sculpted framework can be placed without disrupting the blood supply to the skin. This is like putting a 5-pound object into a space that can hold a 2-pound object, and doing this in vivo! In addition, because cartilage cannot be shown on x-ray in the same way as mature bone, it is impossible for the surgeon to know how well the rib cartilage is developing before the surgery. No matter how difficult it is, the surgeon must do his best to sculpt an auricular scaffold that is as realistic as possible. Sculpting the implant from the patient’s own rib cartilage is by far the most sophisticated technique. An auricle made from one’s own rib cartilage is “living” and therefore can grow with age, whereas an auricle made from artificial material obviously cannot grow with age. The benefits of using your own living tissue to repair the auricle are obvious. The auricle is “living” and can grow with age, and can repair itself after damage. The child can play general sports, such as swimming and gym classes, 4-6 weeks after surgery without any special concern for trauma to the auricle. Basically, there is no need to restrict any sports in particular. Because it is a living tissue reconstruction, the child can participate in sports at 5 weeks postoperatively without any special concern for the operated ear or chest wall. If there is post-operative discomfort in the following stages II and III of the procedure, also mainly in the ear, these can be addressed on an outpatient basis. Allografts are considered “foreign material” by the body, and to ensure the success of the transplant, patients need to take medications for the rest of their lives to prevent rejection, which can have very serious side effects, such as causing heart or kidney problems. In fact, the doctor only needs to spend an extra 20 minutes to take the patient’s rib cartilage and another 30 minutes to sculpt it, using allogeneic tissue is not necessary. Artificial materials are currently subject to further research. III. Hearing problems in patients with microtia? Most patients with microtia have unilateral disease with one normal ear. Although they have adapted to hearing in one ear, they still have problems with sound localization and hearing in noisy environments. In the case of bilateral malformations, the problem is more severe and these children must be fitted with bone-conduction hearing aids in the first few months of life to facilitate their speech development. A brainstem auditory evoked potential (BAER) can be performed within a few days or 2 weeks of birth in children with microtia, and the BAER can detect hearing problems much earlier than electrical audiometry. In the case of binaural malformations, this test is even more important. Children with monaural hearing usually do not need hearing aids, but patients with bilateral microtia need hearing aids to help with their speech development. If the microtia is unilateral, these children do not need a hearing aid and their speech development is mostly good. A bone-anchored hearing aid (BAHA) is a box-shaped device that is attached to a metal fixator that is anchored to the skull by two surgical methods, and this hearing device can provide better sound quality than traditional bone-conduction hearing aids. It needs to be surgically placed and requires scalp care during hearing aid application. If a bone-anchored hearing aid is placed prior to auricular contouring, it is required to be placed very far back in the skull to prevent the resulting scar from interfering with the later auricular reconstruction. Many BAHAs are placed improperly resulting in lost opportunities for auricular reconstruction. I believe it is best to wait until after auricular reconstruction if considering BAHA implantation for a child. In children with bilateral ear deformities, a traditional bone-conduction hearing aid can be used first, and then BAHA surgery can be performed after the auricular deformity has been repaired. Children (with or without microtia) are prone to ear infections and must be especially aggressive in treating infections in the healthy ear of microtia. If ear infections occur frequently in these children, it is important to monitor hearing and speech development frequently. Because the urinary tract develops at the same time as the ear, malformations of the urinary tract are more common in patients with microtia (about 4%). A renal ultrasound can provide information about the kidneys. IV. Does auricular repair or external canalplasty and tympanoplasty come first? The surgeon usually uses rib cartilage sculpted into an auricular scaffold for implantation. The result of auricular deformity repair depends on a pristine, scar-free skin in the area of the ear implant. Reconstructing the auricle first to repair a microtia does not interfere with external ear canal surgery for atresia, but the reverse is not true. If external ear canalplasty is done first, the skin in the area is no longer suitable for auricular reconstruction and the surgeon must replace the original good skin with a fascial flap to cover the ear scaffold. If the atretic external auditory canal is not opened at an early age, will the auditory center not be able to understand the information it is receiving again when hearing reconstruction is performed at an older age? While this concern is perfectly valid for the visual system, fortunately, it is completely unnecessary for the auditory system. Signals from one ear are transmitted to the same side of the brain and to the other brain early in the entire auditory reflex pathway; in other words, from birth (and even earlier) the bilateral auditory centers work together to collect and process the information coming from both ears. This means that regardless of when the external auditory atresia opens, the bilateral auditory center can process and understand the new signals it receives. For these reasons, we recommend delaying surgery for microtia/External Auditory Canal Atresia until after the age of 6-8 years. In patients with unilateral external auditory atresia, opening the atretic canal may improve the child’s hearing in noisy environments (noisy classrooms, playgrounds, etc.) as well as spatial localization of sound. About 50% of patients with microtia/atresia have a well-developed middle ear, making them suitable for reconstructive hearing surgery, which requires a CT scan to determine. The purpose is to: (1) detect the presence of congenital cholesteatoma (15% prevalence in patients with atresia). (2) To find out the development of the middle ear mastoid. (3) To detect malformations of the auditory chain. (4) To understand the development of the inner ear. Because there is not much damage in the middle ear and external auditory canal even if cholesteatoma is present in the early stage, CT examination of the middle ear mastoid is required only at the age of 3-4 years. Another CT scan is required before surgery at 6-8 years of age. CT scans can give us information about the development of the middle ear and help us decide if the patient is a good candidate for functional hearing reconstruction. Treatment of congenital auricular malformation with external auditory canal closure requires close cooperation between the otologist and the plastic surgeon. The repair of congenital auricular deformity can be divided into 3-4 stages. The work of the plastic surgeon should be carried out first, and an important improvement in the current procedure is to organically arrange hearing reconstruction and ossicular reconstruction in a staged surgical sequence, so that the patient can complete hearing and ossicular reconstruction and rehabilitation in the shortest possible time, and to achieve complete repair of congenital auricular deformity with atresia in stages. Stage I: total auricular reconstruction (auricular scaffold made of own rib cartilage); Stage II: external auditory canal reconstruction and hearing reconstruction with earlobe and ear screen reconstruction; Stage III: standing ear (reconstructed ear lifted from the mastoid skin area to form an otocranial angle between the skull and the ear); Stage IV: further auricular detail repair (if necessary). Patients with unilateral external atresia should undergo surgery earlier when there is evidence of middle ear cholesteatoma, infection or a thin atresia membrane. Children with congenital auricular anomalies, especially unilateral patients, should usually undergo repair surgery after the age of six to eight years. This depends on the child’s growth and development. Patients with bilateral congenital auricular anomalies combined with external atresia may be operated earlier, but total ear reconstruction should only be performed if the child has sufficient cartilage tissue. V. Surgical risks The technical difficulty and risks of ear reconstruction and hearing reconstruction surgery are high, and the surgical results are difficult to achieve normal status in terms of aesthetics and hearing recovery, so both parents and patients must be aware of this. The placement of the cartilage graft during surgery may cause skin gangrene due to severe pulling on the surface of the skin. 1 to 2 mm of skin gangrene can be treated with ointment and careful observation to wait for healing. If the gangrenous skin area exceeds 5 mm, it can be repaired with a tipped parietal temporal flap, which may develop chondromalacia with cartilage resorption; improper placement of the cartilage scaffold and resorption of the cartilage can cause infection. All grafting steps have the potential for graft failure. There is also a higher chance of keloid formation than with flaps taken from the abdomen and buttocks. In addition, malpositioning of the reconstructed ear and contraction of the posterior auricular graft are associated with keloid formation in the donor or skin graft area. Not all patients with ear deformities are candidates for ear canal reconstruction and hearing reconstruction, requiring a thorough audiological and middle ear mastoid development morphologic evaluation by an audiologist and otologist. The risks are even greater for auditory reconstruction, as the procedure involves the facial and auditory nerves, which can lead to serious complications with little care. Therefore, the concept of holistic reconstruction needs to be emphasized, with the otologist and plastic surgeon working as a team to reconstruct and repair both the auricular deformity and external auditory atresia. Plastic surgeons performing auricular reconstruction surgery should ensure that the otologist has completed the necessary audiologic and imaging evaluations. Prosthetic ears and hearing aids may be an option for patients who are not candidates for surgery. Breakthroughs in cell culture and cell scaffolding techniques in tissue engineering will impact the future of total auricular reconstructive surgery. We are committed to this research and look forward to breakthroughs.