What is Microtia?

A congenital malformation of the external ear, seen more frequently in males, that occurs sporadically or is inherited, that is characterized by unilateral (79-93% of cases, 60% of which involve the right ear) or bilateral small and abnormally shaped auricles and that is often associated with atresia or stenosis of the ear canal, attention deficit disorders and delayed language development. The variation in auricle size ranges from grade I, where the auricle is simply smaller than normal, to grade IV, also known as anotia, where there is a complete absence of the external ear and of the auditory canal.

Inheritance type

Autosomal dominant, Autosomal recessive, Not applicable


  • United States: 1-5 in 10,000

Age of Onset

  • Infancy
  • Neonatal
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