Introduction
Microtia is a congenital deformity where the pinna (external ear) is underdeveloped. A completely undeveloped pinna is referred to as anotia. Because microtia and anotia have the same origin, they can be thought of as different degrees of the same condition.
Grades of Microtia
- Grade 1: A slightly small ear with identifiable structures and a small but present external ear canal.
- Grade 2: A partial or hemi-ear with blockage or stenosis of the external ear canal producing a conductive hearing loss.
- Grade 3: Absence of the external ear with a small peanut-like vestige structure and an absence of the external ear canal and ear drum. This is the most common form of microtia.
- Grade 4: Absence of the total ear (anotia).
Prevalence and Causes
Microtia occurs in about 1 in every 6,000 to 12,000 births. It occurs more often in males and on the right side. The exact cause is usually unknown, though it can sometimes be associated with genetic conditions like Treacher Collins Syndrome or Hemifacial Microsomia.
Next Steps
If your child is born with Microtia, the first step is usually a hearing test (ABR) to ensure the inner ear is functioning correctly.