Auricular hypoplasia generally refers to congenital microtia, with genetic factors being the main factor in bilateral auricular hypoplasia. Congenital microtia refers to a smaller than normal auricle, often accompanied by atresia of the external auditory canal. The main targets of auricular reconstruction are congenital microtia and traumatic ear defects. The incidence of congenital microtia is approximately 6,000:1, with the right side being more prevalent at about 60%, the left side at 33%, and the bilateral microtia at 7%. The typical microtia patient has a small redundant ear that does not grow with age, so surgery is the only way to recreate a normal sized ear. Bilateral microtia symptoms need to be distinguished from the following symptoms: Otitis externa is a disease of the external ear that occurs in the summer and is most common in humid, warm climates. The Yangtze and Pearl River valleys of China are prone to this disease. Most scholars believe that Aspergillus, Penicillium and Candida are the most common fungi causing otitis externa, and that the causes are swimming, showering, prolonged pus in the middle ear and inappropriate medication in the ear. As a result, the external ear canal is wet for a long time, and the warm environment makes the fungus grow easily. In addition, ear-digging injury is also one of the important factors for secondary development of this disease. Fungal otitis externa may be asymptomatic in the early stages, but there is usually an itchy or strange itching and stuffy feeling in the ear, with a small amount of watery discharge. If the inflammation causes the epithelium and mycelium to form a scab, which blocks the external auditory canal or covers the surface of the tympanic membrane, hearing loss and tinnitus may occur. If there is bacterial infection, it can cause swelling, pain and pus in the external ear canal. On examination, white, gray, yellow or smoky gray mold moss is often seen in the deep part of the external ear canal, which looks like a film or fan, much like mold. When the film is removed, the skin of the external auditory canal is congested and swollen, and the surface is mildly eroded or has a small amount of blood leakage. The mold moss is placed on a slide, and a little 10% potassium hydroxide solution is added drop by drop, covered and properly warmed, and if mycelium or budding cells are seen under the microscope, the diagnosis is clear.