Microtia

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Unilateral Grade III microtia (left side).
Unilateral Grade III microtia (left side).

Microtia (meaning 'Small ear') is a congenital deformity of the pinna (outer ear). It can be unilateral (one side only) or bilateral (affecting both sides). It occurs in 1 out of about 8,000-10,000 births. In unilateral microtia, the right ear is most typically affected. There are four grades of microtia [1]:

  • Grade I: A slightly small ear with identifiable structures and a small but present external ear canal
  • Grade II: A partial or hemi-ear with a closed off or stenotic external ear canal producing a conductive hearing loss
  • Grade III: Absence of the external ear with a small peanut vestige structure and an absence of the external ear canal and ear drum
  • Grade IV: Absence of the total ear or anotia.

Grade III is most common, and can be corrected by surgery. Typically, testing is first done to determine if the inner ear is intact and hearing is normal. If hearing is normal, the next step (if a canal is not visible externally) will be to determine if a canal exists, by CT scan. For younger patients, this is done under sedation. Age when outer ear surgery can be attempted depends on the technique chosen (see below). The earliest age surgery can be attempted is age 3 for Medpor and 5 1/2 for Rib Graft. Less experienced surgeons may recommend waiting until a later age, such as 8-10 when the ear is full adult size.

[edit] Options

There are two separate issues in microtia surgery:

1) Auricular reconstruction to restore the visual appearance and form of the outer ear

2) Repair of atresia or application of a bone-anchored hearing aid BAHA to restore hearing. Unilateral deafness is not generally considered a serious disability, especially when the person is able to adjust to it from birth. In some areas the benefits of intervention to enable hearing in the microtic ear are not considered to outweigh the risks, except in bilateral microtia. However, children with untreated unilateral hearing loss are eight to ten times more likely to have to repeat a grade in school. If surgery or aids are not used, special steps should be taken to ensure that the child is accessing and understanding all of the verbal information presented in school settings. Age for BAHA implantation depends on whether you are in Europe (18 months) or the US (age 5). If the child is under the age for surgical implantation, the BAHA can be worn on a headband

For auricular reconstruction, there are five different options:

1) Rib-Graft Reconstruction. Usually performed after age 6 to ensure that the ear has stopped growing and the rib cage is large enough to provide the donor material necessary. This is a three to five stage surgery. The number of surgeries can vary. The foremost surgeon in the United States in rib graft microtia reconstruction is Dr. Burt Brent.

2) Reconstruct the ear using a Medpor polyethelene plastic implant. This is a two stage surgery which can start around age 3. Note that for patients with both Microtia and Atresia, that when using Medpor for the outer ear reconstruction the atresia repair must be done FIRST (as mentioned above with the rib graft reconstruction, the atresia repair is done AFTER). The foremost surgeon in the United States for Medpor microtia reconstruction is Dr. John Reinisch

3) Ear Prosthesis. A craniofacial prosthesis or auricular (ear) prosthesis is custom made by an anaplastologist to mirror the other ear. Prosthetic ears can appear very realistic yet they do require a few minutes daily care. They are typically made of silicone which is colored to match your individual skin and can be attached using adhesive or with titanium screws inserted into the skull to which the prosthetic is attached with a magnetic or bar/clip type system. These screws are the same as the BAHA (bone anchored hearing aid) screws and can be placed simultaneously. The optimal age to begin wearing an ear prosthesis between the age of 6 and 9. The child should be mature enough to want and help care for the prosthesis.[1] A person with grade I & II microtia need not consider an ear prosthesis. A person with grade IV (anotia) should consider the following options 'b' & 'c'. A person with grade III construction has three options for reconstruction. a) Leave the skin tags for future surgical reconstructive purposes and make an adhesive retained prosthesis over the top of the existing ear. The advantages is that you can keep your reconstructive options open and you get more definition in the ear. This allows you to try out the prosthetic approach without burning any bridges. It is also the least expensive approach. The disadvantage is that the ear is typically placed lower and more forward and tends to appear more bulky than the other ear. Placement is more difficult than prosthetics option 'b'. b) Remove the skin tags and use an adhesive retained ear. The advantage over prosthetic option 'a' is that your prosthetic ear can be a near identical mirror image of your other ear. Placement is much easier as well because the skin is flat. The disadvantage is that you remove the skin tags which are necessary for surgical reconstruction. c) Remove the skin tags and simultaneously place the implants for a prosthesis. The visual results are very similar to prosthetic option 'b'. The advantage is that placement of the ear becomes even easier and you eliminate the costs of adhesive and the associated daily care. The disadvantage is again that you limit your surgical reconstructive options.

4) Soft tissue reconstruction: well known Dr. Roland Eavey in Mass is very successful using this method. The reasoning for soft tissue reconstruction is that surgically reconstructed ears using rib-graft or implants are sensitive, though the sensation is not the same as for normal ears due to the transplant of skin from other areas of the body.

5) Do nothing.

[edit] Complications

Aural atresia is commonly associated with microtia. Atresia occurs because patients with microtia may not have an external opening to the ear canal, though the cochlea and inner ear are usually present. The grade of microtia correlates to the development of the middle ear[2].

Microtia is usually isolated, but may occur in conjunction with hemifacial microsoma or Treacher-Collins Syndrome[3].

Microtia can cause difficulties with wearing headphones and glasses[4]. It is also occasionally associated with syndromes that can cause balance problems, kidney problems, and jaw problems, and more rarely, heart defects and vertebral deformities.

If a canal is built where one does not exist, minor complications can arise from the body's natural tendency to heal an open wound closed. Atresia patients who opt for surgery will have the canal packed with gelatin sponge and silicone sheeting to prevent closure [5].

[edit] Patient Support

AboutFace[6] is an international organization providing information and emotional support to individuals and their families affected by facial differences and disfigurements.

A parent support group specifically dedicated to Atresia and Microtia is located on Yahoo Groups

  • The Let Them Hear Foundation A 501(c)(3) non-profit who provides free insurance appeal assistance to individuals who have been turned down by their insurers for atresia repair or auricular reconstruction with an experienced surgeon.

A conference concerning microtia treatment options is sponsored by the Let Them Hear Foundation and held in Palo Alto, California. The conference is always the first Saturday in October. Conference attendees will be able to see presentations on both medpor and rib graft microtia reconstruction, atresia repair, prosthetics, jaw distraction and Baha devices.

In some countries, the outer ear reconstruction is considered as a prosthetic surgery, which means that it is not necessary, and hence is not covered by the insurance or support groups help.

Some patients may opt to not pursue surgery. This is usually because the child has already adapted to the condition, and unless is driven by self-esteem or cosmetic issues, may prefer to leave the condition unchanged.

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