Microtia and Aural Atresia
Microtia, meaning “little ear,” is a congenital deformity of the external ear that varies from minor abnormalities of the ear to a marked absence of ear development. Microtia is not always accompanied by aural atresia.
Aural atresia is a defect of the ear canal, in which incomplete formation or total absence of the canal results in hearing loss. Aural atresia often occurs in conjunction with microtia.
Microtia and aural atresia are congenital conditions, meaning that the ear and hearing bones were formed this way before birth. In the majority of patients, they occur for unknown reasons. In a few cases, they appear to be genetically inherited.
There are four stages of severity by which the physician will classify your child’s case of microtia with or without aural atresia. These stages vary from stage I, in which the child presents with a tiny ear accompanied by a narrow ear canal, to stage IV, which indicates a total absence of the ear, also called anotia.
At the same time our ear team takes care of the external ear and the hearing issues, the Oral and Maxillofacial Surgery team at the Massachusetts General Hospital may be involved for jaw evaluation in microtia patients. Our findings demonstrate that nearly half of patients with microtia also have jaw malformations. Most of the time, fortunately, patients with microtia have an isolated condition and no other major congenital anomalies.
Hearing with Aural Atresia and Microtia
Aural atresia and microtia typically occur only on one side. If the other side hears normally, the child's speech and language development will be normal. However, bilateral cases of aural atresia and/or microtia (meaning that both ears are affected) do sometimes occur. When aural atresia occurs bilaterally, the physician will involve an audiologist to treat any hearing loss.
Treatment for Aural Atresia and Microtia
Microtia patients with or without aural atresia should have their hearing checked by an audiologist periodically. The physician will also recommend periodic high resolution CT scans to keep an eye on the development of the middle ear. When the child reaches the age of 5 or 6, surgery may be recommended to correct microtia with or without aural atresia.
There are several treatment options for patients with microtia. The most common intervention, involving multiple stages of surgery, is to harvest rib tissue and to carve it into the shape of an ear and then implant it under the skin where the ear should be. Subsequent procedures are performed to move tissue to create an earlobe and to separate the ear from the side of the head and to give the reconstructed ear finer detail.
Another technique is to use a prosthetic ear in which titanium screws are implanted into the side of the head. An artificial ear is attached later.
A third technique, in the appropriate patient, is to inconspicuously borrow tissue from behind the normal ear. This cartilage and skin can be used to create an enhanced ear appearance on the side with microtia.
In cases microtia with aural atresia, a decision can be made to drill and reconstruct the external canal.
Each procedure to correct microtia, and the option to surgically reconstruct cases of aural atresia, should be made with your child’s physician.
It is important to weigh the pros and cons of surgical intervention with your physician and to remember that in the larger picture you have a wonderful baby that has a smaller issue involving an ear. Our physicians are here to evaluate and inform to help you make the best decision for your child.
Tessa A. Hadlock, M.D.
Jennifer Smullen, M.D.