Microtia occurs in approximately one in every 7,000 to 8,000 births.
The exact cause of microtia is not completely understood, but it is believed that hereditary factors, as well as in utero vascular accidents are responsible. Microtia is often seen with other craniofacial deformities. Commonly, microtia is found in patients with hemifacial microsomia, Treacher Collins syndrome, facial asymmetry, epibulbar dermoids, malocclusion, facial nerve weakness and macrostomia.
There are four categories of microtia:
- Grade I: slightly small ear with identifiable structures with a present external ear canal.
- Grade II: partial or hemi-ear with a closed off or stenotic external ear canal producing. There is a conductive hearing loss.
- Grade III: absence of the external ear with a small vestigial ear structure. There is no external ear canal or inner eardrum.
- Grade IV: Total absence of the ear. Also known as Anotia.
A UF Health otolaryngologist will evaluate the hearing and middle ear status and advise treatment. Patients are given a hearing test first and may be candidates for a bone anchored hearing aid (BAHA). Otherwise, they may benefit from inner ear canal reconstruction. A CT scan will be performed to evaluate the middle ear anatomy. Depending on a patient’s wishes, he/she may be a candidate for external ear reconstruction or fabrication of a prosthesis to match the other ear. Treatment for the external ear deformity is usually a staged process, conducted by a plastic surgeon in three or four operations. The patient’s own rib cartilage is used in the reconstruction. The second form of treatment is a prosthesis, or artificial ear, that is secured by an implantable device.