The auricular hypoplasia generally refers to congenital microtia, which is caused by the hypoplasia of the first and second gill arches or the first gill sulcus during embryonic development, and may be accompanied by malformation of the eustachian tube, tympanic ventricle, or mastoid process caused by hypoplasia of the first pharyngeal sac. The majority of microtia are composed of small cartilage masses with no auricular shape and a more normal but displaced earlobe. In these cases, there is no external auditory canal or tympanic chamber, and the auditory bones are hypoplastic, resulting in hearing impairment. Examination of bilateral auricular hypoplasia: 1. Level 1: The auricle is smaller than normal and can still be distinguished, the external auditory canal is present or partially atretic, and the tympanic membrane is present. Hearing is not yet possible. Grade 2: The base of the auricle is in the form of a striated protrusion, which is equivalent to the ear chakra, the external auditory canal is atretic, and the tympanic membrane and pendulous stalk are not developed. The stapes is fertile or infertile. This is a common clinical type, about twice as common as grade 1, and presents with conductive deafness. 3. Grade 3: The auricle is mutilated with only sporadic but regular protrusions. The external auditory canal, malformation of the auditory chain, with inner ear dysfunction, has the lowest incidence of about 2%. Grade 2 and 3 malformations may be accompanied by maxillofacial hypoplasia called Treocher Collins syndrome, which is characterized by pectus excavatum, zygoma, maxilla, mandible, mouth and nose. It is accompanied by microtia, external auditory canal atresia and auditory bone malformation. CT examination of otorhinolaryngology: CT examination of otorhinolaryngology is a method of examining the otorhinolaryngology by CT. Bacterial culture of ear, nose and throat swabs: Bacteria in the ear, nose and throat come from outside and are not pathogenic under normal circumstances. However, infection can occur when the body’s systemic or local resistance decreases and other external factors can lead to disease. Therefore, bacterial culture of ear, nose and throat swabs can isolate pathogenic bacteria and help in the diagnosis of otitis media, rhinitis, sinusitis, diphtheria, purulent tonsillitis, acute pharyngitis, etc. The specimen is taken by the physician using a sterile cotton swab and the secretion from the patient’s lesion is sent for examination. As a characteristic sign of microtia is the hypoplasia of the outer ear. In mild cases, the parts of the auricle are still recognizable, but the outline is small; in moderate cases, most of the structures of the auricle are indistinguishable and appear as irregular and simple structures; in severe cases, the auricle is simply barely developed, and the residual ear is only a small mound, etc., or only an earlobe is present. CT scan can be used to understand the ear canal and middle ear deformity.