About Microtia

Microtia is a condition in which there is an incomplete or abnormally formed ear. The name comes from the words “micro” (=small) and “otia” (=ear). Microtia may affect one side only (unilateral) or affect both ears (bilateral). In 80% of the time it is unilateral.

Microtia occurs in around 1 in 8000 births. It is twice as common in males, and affects the right hand ear twice as often as the left. Some races are affected more frequently (Japanese and American Indians).

Microtia may occur in patients with no other problems, or it may occur as part of a syndrome. The most common syndrome which can include microtia is hemifacial microsomia (sometimes known as craniofacial microsomia). In this condition one side of the face, in particular the jaw, is smaller than the other. There may also be weakness of some of the facial muscles on the affected side. Treacher Collins syndrome, in which the eyes and facial bones are affected, is another condition that may be associated with microtia. In this condition the microtia is usually bilateral.

The cause of isolated microtia is not fully understood, but is thought to be multifactorial in origin. It may occasionally run in families, but usually the chance of an affected parent transmitting microtia to a child is only small (around 6%). There has been some evidence to link the use of isotretinoin during surgery to microtia, but in most cases no cause is ever identified.