Children born with microtia will have an underdeveloped or absent outer ear. Because of this, they will usually have atresia, which is an absence or underdevelopment of the ear canal and middle ear. It usually only affects one ear, and occurs more often in boys than girls. Because it usually doesn’t affect the inner ear, children with unilateral (one-side) microtia usually have normal hearing in the other ear. Children with bilateral (two-sides) microtia will typically not be able to hear without assistance.
The exact cause of microtia is unknown. It could be caused by a lack of blood flow to the ear during development. Certain medications during pregnancy and environmental factors are also possible causes.
Microtia is a common characteristic of hemifacial microsomia, Goldenhar syndrome and Treacher-Collins syndrome.
Treatment may involve surgery to open the ear canal. Repair of congenital microtia requires the coordinated efforts of both facial plastic surgeon and ear surgeon. Reconstruction of the microtic ear is usually delayed until the child is four to five years old. At that age, cartilage from the rib is used to reconstruct the external ear. Several operations may be necessary. The ear surgeon will usually delay reconstruction of the external auditory canal, (i.e. correction of the atresia), until the initial phases of the microtia repair are completed. Some children with bilateral microtia will require a bone conduction hearing aid in order to hear.
Most children born with with these conditions are able to lead healthy lives.