Microtia
What is microtia?
Microtia is a congenital deformity of the outer ear where the ear does not fully develop during the first trimester of pregnancy. The word “microtia” means “little ear”, from the Latin words “micro” and “otia”. Microtia ears vary in appearance, and are usually smaller in size, often only consisting of a tiny peanut-shaped lobe. Microtia occurs about 1 in 5,000 births, though rates can vary depending on ethnic background. In 90% of cases, it affects only one ear, usually the right ear, and is more common in males. Microtia describes the outer ear, but is often associated with absence of the ear canal (called canal atresia or aural atresia), or an extremely narrow ear canal (canal stenosis).
The four grades of microtia:
- Grade 1: The ear is smaller than normal but the key features of the normal ear are present, though they may have minor alterations in shape or form.
- Grade 2: Some of the features of the ear are missing, though usually much of the lower two-thirds of the ear is still present. Grade 2 microtia is sometimes called “conchal type microtia.” The ear canal may be present, but frequently is very narrow (canal stenosis).
- Grade 3: This is the most common type of microtia, in which the only feature remaining is a small peanut-shaped remnant ear lobe. Grade 3 microtia is sometimes called “lobular type microtia.” The ear canal is usually completely absent (aural atresia).
- Grade 4: Complete absence of the external ear without any remnant. This is called “anotia”, and is rarely seen.