Severe microtia is not a congenital absence of the ear. It is one part of the first branchial cleft syndrome. The other two parts are middle ear anomalies and microsomia. Hemifacial microsomia specifies facial variations due to anomalies of the first and second arches. All elements of these arches are affected to a greater or lesser degree. Although I have observed a general correlation between the severity of microtia and middle ear deformities, I have not found the same correspondence between microtia and microsomia. Thus, a severe microtia can co-exist with little facial deformity, and vice versa. The reason for this discrepancy remains obscure.
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