Diagnosing and Treating Microtia

Abstract

Severe hypoplasia of the external ear (microtia) is commonly encountered in any pediatric plastic surgical practice. A useful clinical classification of these anomalies was proposed by Tanzer [1]:A. Anotia (complete absence of ear) B. Microtia 1. constricted (cup or lop) ear 2. cryptotia (in which the top of the auricle is hidden under the scalp) 3. hypoplasia of the entire superior third of the auricle C. Hypoplasia of the middle third of the auricle D. Hypoplasia of the superior third of the auricle E. Prominent ears 1. complete hypoplasia of the auricle (external ear) with atresia of the external auditory canal 2. complete hypoplasia of the auricle without atresia of the external auditory canal EpidemiologyBased on analyses of large birth registries of congenital malformations [2-4], the incidence of microtia has been estimated at between 1 in 4,000 to 1 in 12,000 births. Microtia affects about 1.5 times more male children than female, and those with the condition are nearly three times more likely to be of Hispanic descent, and almost twice as likely to be of Asian descent, than to be black or white. Signs and SymptomsMicrotia is noted on visual inspection at birth as an obvious hypoplastic external ear deformity. A variable extent of middle ear pathology, with associated conductive hearing loss, is expected. Pertinent History, including Developmental HistoryKey clinical information should be obtained at the initial visit (typically when the child is an infant): pregnancy and labor complications, maternal drug use or toxin exposure, and family history of craniofacial or other anomalies. A developmental assessment should be made, specifically inquiring about the child's behavior, school performance, social interaction with peers, and self-esteem, to inform expectations of patient cooperation and compliance during the reconstructive process.