Microtia

Microtia, meaning "small ear," is a birth defect of the outer ear. The defect varies in severity, from an ear that's slightly small to complete absence of the outer ear. It can be unilateral (affecting one ear only) or bilateral (affecting both ears). In unilateral microtia, the right ear is typically the one with the defect.

Children with microtia may also have defects of the middle ear structures, which can be diagnosed by CT scans. In severe cases, the ear canal is usually closed, which is called ear canal atresia. In children with ear canal atresia, hearing in the affected ear is severely reduced.

Microtia is found in one out of every 8,000 to 10,000 newborns. It can occur alone or as part of a syndrome that causes other defects, such as hemifacial microsomia. The cause of microtia is unknown.

Microtia is diagnosed based on its physical characteristics. The condition is graded according to its severity, with one being the least affected to three being the most affected, with most of the external ear missing.