Microtia refers to a small, abnormally shaped ear, which can range from a minimally deformed small ear to a complete absence of the ear. This occurs in about one in 7,000 births and is more common in males and on the right side. Most cases (90%) are on just one side (unilateral), but this can affect both ears as well (bilateral).
Typical microtia, referred to as grade 3, is a peanut-shaped remnant of skin and cartilage where the ear should be. Grade 2 microtia has some portions of the ear present, and a Grade 1 microtia looks mostly like a small ear. Anotia refers to complete absence of the ear.
Microtia is usually an isolated condition but can be associated with other facial malformations such as a small jaw or craniofacial syndromes. It is very common for patients with microtia to have aural atresia (no ear canal). Microtia is usually incidental, and nothing a mother did during pregnancy caused the ear deformity.
Aural atresia is the absence of the ear canal. The outer ear and ear canal develop at the same time, which means that microtia and atresia are commonly found together. This causes a hearing loss (usually a “maximal conductive loss”) because the sound waves cannot get through to the eardrum/inner ear. Usually, the nerve for hearing and inner ear is normal, and this can be determined with a hearing test (audiogram).
Associated Medical & Social Issues
There are two main problems in children with microtia/atresia: hearing loss and cosmetic deformity. Hearing loss is the top priority – studies have shown that children with hearing loss even just on one side can have increased difficulties in school. This can also affect interactions with friends and family. Some children with hearing loss on one side do very well without intervention, but we strive to achieve the highest potential for each child and monitor their hearing status very closely.
The cosmetic deformity of having an abnormally shaped ear can be surprising for parents, but children do not usually notice that they are “different” until around age 4-6. This can cause some shyness or self-consciousness with friends, but children can be counseled to refer to their microtic ear as their “little ear” and it becomes less of an issue. Children with microtia are usually normal kids who just happen to be missing an ear.
There are several treatment options for microtia: reconstruction of the ear, a prosthetic ear, or just leaving it alone. Lurie Children’s Microtia Program staff counsel parents on all of the options during the initial visit.
One way it is treated it to perform ear reconstructions using cartilage, which is sculpted into a new ear and placed under the skin on the microtic side. The cartilage is from the child’s own ribs. This method is preferred rather than using synthetic implants because the cartilage is part of the child’s own body, and after surgery and the ear heals, there are no restrictions on activity. The reconstructed ear will continue to grow with the child. Most children do not undergo surgery to treat microtia until the ear has stopped growing usually around 10 years of age.
Atresia with Hearing Loss Treatment
All children with aural atresia undergo a formal hearing test (audiogram), usually between 6 and 12 months of age. Then, they should have their hearing checked at least yearly, or anytime there is a major change. Children with bilateral atresia are typically fitted with a headband which has hearing aids attached, so that they may hear sounds and develop speech in a normal fashion.
One option for treatment is an “osseointegrated” hearing device — either the BAHA® Attract or Sophono Alpha 2. Lurie Children’s is one of the first centers in the U.S. to implant the BAHA® Attract, a new device to aid in hearing rehabilitation. These are hearing processors that attach to a magnetic device implanted under the skin. The device sends the hearing signal from the bone directly to the hearing nerve to transmit sound. The device is safe and implanted with one surgery. Activation is done only one month later. When children reach age 5, they are candidates for implantation and are tested with the audiologists to see if this will benefit them.