Microtia: What is it?

Microtia is a congenital condition in which the ear does not develop properly. The word Microtia translates to “small ear.”

Children with Microtia


What are the different types of Microtia?

Microtia occurs in many different variations, ranging from just a small ear to complete absence of the ear, called anotia meaning “no ear.”  In some cases, the ear canal is very small (aural stenosis) or absent (aural atresia).

Several systems have been developed to describe different types of microtia. One of the most common systems used to categorize these different “grades” is illustrated below:

Grades of Microtia

How Common is Microtia?

Microtia occurs about once in every 6,000 to 12,000 births, with a higher frequency among Hispanics, Asians, Native Americans, and Andeans.

What Causes Microtia?

The cause of Microtia is not well understood, particularly regarding the role of environmental and genetic factors. Genetics are thought to be a cause in only 5% of all patients. Multiple theories have been proposed to explain the cause of Microtia during fetal development, such as neural crest cells disturbance, vascular disruption, and altitude, but these have not been proven.

It is important to understand that nothing a mother does during pregnancy, such as drinking coffee, alcohol use, or even drug abuse, has been shown to cause Microtia. However, when taken in the first trimester of pregnancy, some medications have been linked to Microtia, including Thalidomide and Accutane.

Can Microtia Involve More Than One Ear?

Microtia usually occurs on only one side (more commonly on the right), but about 10% of patients have microtia on both sides (Bilateral Microtia).

Microtia is often seen as an isolated condition, but it may also occur with other syndromes including Hemifacial Microsomia, Goldenhar Syndrome, or Treacher Collins Syndrome.  Other syndromes with Microtia can also affect the kidneys, the heart, the eyes, the craniofacial bones, and the skeletal system. These children are often cared for by a Craniofacial Team.

bilateral microtia hemifacial microsomia goldenhar syndrome treacher collins syndrome
Bilateral Microtia Hemifacial Microsomia Goldenhar Syndrome Treacher Collins Syndrome

Can My Child Hear?

If your child does not have a normal ear canal, eardrum and middle ear bones, then he or she will not have normal hearing. However, children with Microtia can still hear some sounds even if they don’t have an ear canal (this is called aural atresia), since the nerve used in hearing often functions normally. See Hearing Loss


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