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Microtia literally means "little ear." Such an ear is formed this way before birth. Usually there is a corresponding absence of the ear canal and opening (meatus).
Often the microtia ear, looks like a small narrow structure with some ear cartilage on the top connected to earlobe-like tissue on the bottom. It is usually about the
size of half a small finger. Variations in size and shape can occur.
In the majority of patients, the condition appears to occur for unknown reasons. In a few cases, microtia appears to be genetically inherited, since more than one member of the family can have this condition. Certain drugs can cause microtia such as thalidomide or Accutane™ but these drugs are seldom taken. There are theories about how intrauterine blood vessel development can be involved or how certain cells (neural crest cells) might have difficulty migrating to their final normal location during the early embryonic stages.
Microtia usually occurs and therefore affects, only one side. The other side usually hears normally. Therefore, the child's speech and language will be normal. A hearing test is essential, however, because sometimes the normal appearing ear might actually not hear. (To understand how this could be, consider children who attend a school of the deaf. Their external ears look normal but they do not hear.) The ear with microtia usually has an approximately 60 dB hearing loss. (This is about the level one would hear if you had a finger plugged in the ear canal.)
Microtia can be operated on for correction.
There are several options for patients with microtia. Each procedure has advantages and disadvantages. The standard procedure 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.
A new science called tissue engineering has produced an image that many people have seen in the broadcast media that was referred to as "the mouse with an ear on its back." This technique was developed by Dr. Charles Vacanti in his tissue engineering lab, located at the University of Massachusetts Medical School in Worcester. We have worked with Dr. Vacanti for the past several years and have helped his team move beyond the mouse hopefully towards an eventual human application.
After a reconstruction for the external ear has been started, it is not uncommon for a CT scan to reveal that there are some structures in the middle ear. However, the anatomy is often inadequate to warrant drilling an opening (aural atresia repair).
Fortunately, there are times when the anatomy is sufficiently favorable that drilling a hole to create a new ear canal and eardrum to connect to the hearing bones in the middle ear is possible. This procedure is called an aural atresia repair.
At the same time our ear team takes care of the external ear and the hearing issues, we join forces with the Oral and Maxillofacial Surgery team at the Massachusetts General Hospital for jaw evaluation in microtia patients. Our findings demonstrate that nearly half of patients with microtia have jaw malformations. Other conditions such as facial paralysis can also co-exist. Most of the time, fortunately, patients with microtia have an isolated condition and no other major congenital anomalies.
Very few surgeons perform surgical correction of microtia on a regular basis. This has to do with the rarity of the condition as well as with the interest of various surgeons. Depending on the type of surgical procedure utilized, surgery could be a single stage, but usually this is a multiple staged procedure.
A malformed ear that undergoes surgery is not "cosmetic" but is a reconstructive procedure. Such surgery differs from cosmetic surgery in which one starts with a relatively normal anatomic structure and is just trying to change its appearance. Therefore, the procedure should be covered by insurance.
There are substantial reasons for waiting until the child is approximately 5 to 6 years of age or older to fix the external ear. Occasionally, with a mild or moderate microtia configuration, the ear can be operated on earlier in life.
Hearing needs to be evaluated. The parents can find out more information about microtia and aural atresia. The jaw can be checked. Current research can be discussed.
Please remember that in the large picture you have a wonderful baby that has a smaller issue involving an ear. Sometimes it can seem that the ear shape overshadows the child; the emphasis should be to try in providing all the love the child normally would need and dealing with the ear in a relatively matter-of-fact fashion.
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