Unilateral and Bilateral Microtia

What Is Microtia?

Microtia is defined as underdevelopment of the ear. This means that the ear is either too small, not shaped as it should be, or both. This disorder usually only affects the outer ear, but in some cases the ear canal is underdeveloped as well. This is called microtia with atresia.

Experts estimate that between one and five children out of every 10,000 are born with this condition.


Types and Grades of Microtia

This condition is commonly unilateral, which means it affects just one ear. In some cases, the condition is bilateral, impacting both ears.

There are four types of microtia:

  • Grade 1: In this, the mildest form, the ear is smaller but in shape.
  • Grade 2: The external ear is missing some structures, and the ear canal may be closed off.
  • Grade 3: This is the most common type, in which the external ear is very small but has an earlobe; the ear canal and eardrum may be missing. 
  • Grade 4: The external ear did not grow, or is missing, known as anotia.

How Does Microtia Occur?

This condition develops very early in a pregnancy due to several factors including:

  • Environmental factors
  • Changes in the baby's genes
  • Other factors

Who’s at Risk for Microtia?

Although there is no identified cause of microtia, several factors can increase your child’s risk of microtia. These include:

  • Use of Accutane or isotretinoin during pregnancy
  • Maternal diabetes
  • A diet low in folic acid and carbohydrates during pregnancy
  • Male sex
  • Those of Hispanic, Asian, or Native American descent

Microtia can occur on its own, but it may also be found in children who have hemifacial microsomia, Goldenhar syndrome, or Treacher Collins syndrome.

Complications of Microtia

The ear's appearance in grades 1 and 2 may not be very noticeable to other people. The features of grades 3 or 4 sometimes attract more attention, and they can cause a person to feel self-conscious and lead to low self-esteem. Some children may also get more ear infections. Children with atresia will also have some conductive hearing loss on the affected side.

How to Prevent Microtia

Since the cause of this condition is often unknown, preventing it isn't always possible. However, women who are thinking of becoming pregnant should talk to their doctors about how to be in the best health. Doctors may recommend:

Symptoms & Diagnosis

Microtia Symptoms

This condition can cause a range of symptoms, such as:

  • An ear that is not shaped properly
  • An ear that is too small
  • A missing ear
  • Hearing loss

How Do Doctors Diagnose Microtia?

Diagnosing this condition doesn't require testing in most cases. It's usually noticed at birth. When your child is older, their doctor may perform a CT Scan to see the internal structure of the ear.

If your child failed a hearing test at birth, their doctor will request an Auditory Brainstem Response Evaluation, to be performed by the audiology team.

Auditory Brainstem Response Evaluation

The Auditory Brainstem Response Evaluation assesses whether cochlea and nerves involved in hearing work properly.

This test happens while your child is asleep. For babies from birth until four months of age this can take place during a nap. Older babies and children under the age of 7 will need anesthesia. If your child is older, they maybe able to lie still long enough to finish the test.

Evaluations take about one hour to perform, but you will likely be in the office for a little longer than this, especially if the test requires anesthesia.


How Does UPMC Children's Hospital Treat Microtia?

Treating the effects of this condition often involves surgery. It is called "reconstructive" because the procedure involves creating a new or more complete ear. Doctors generally wait a few years to start discussing surgical options; by the time a child reaches age 7, their ears have usually grown to almost the size they'll be in adulthood. If both ears are affected, surgery may begin a little earlier.

Ear Reconstruction Surgery

There are several ways to reconstruct an ear with microtia. The most common ways are to use your child’s own rib cartilage or to use a plastic implant (MEDPOR).

Microtia reconstruction using your child’s own cartilage is called Autologous Reconstruction. The process takes several stages. It will begin sometime between 6-12 years of age, depending on the type of reconstruction your child needs.

  • Stage 1: The surgeon will remove cartilage from your child's ribs to form part of the ear. They decide where the ear should be and place the cartilage under the skin.
  • Stage 2: The surgeon will make an earlobe or move the existing earlobe to a more natural location.
  • Stage 3: They insert a skin graft to make the ear stand away from the head.
  • Stage 4: The surgeon uses skin and cartilage from the ear area to create the opening to the ear, including the ear flap that covers the ear canal.

If both ears are affected, surgeons complete stage 1 twice – one procedure for each ear.

The other technique uses a plastic implant in place of your child’s own cartilage. This is sometimes called alloplastic or MEDPOR reconstruction.

This is usually a single stage operation where a skin graft and tissue from the side of the head is used to cover the implant after it is placed in the correct position.

Before Surgery

Your surgical team will give you instructions on what your child can eat or drink before surgery, as well as any medications to avoid. They will also tell you what time to arrive at the hospital, and how long you can expect to stay.

During Surgery

Each operation will take a different amount of time, ranging from just one hour to several hours. Because even one hour can seem like a long wait, bring something with you to keep you busy, such as a book or puzzle, or have a friend come along for company.

After Surgery

You will leave the hospital with special instructions on caring for your child after the procedure is over. It is common for surgical sites to be painful, bleed a little, and even itch. Your team will let you know about any symptoms that might be cause for concern.

Benefits of Reconstructive Surgery

Reconstructive surgery of the ear is meant for cosmetic purposes, so that the ear will have a more normal appearance.

Risks of Reconstructive Surgery

All surgeries have risks, including blood loss, infection of the site, and scarring. Your child may have a slight indention and a scar where cartilage is removed from the rib cage, but these should not be very noticeable. It is possible that the cartilage graft may not be successful if the blood supply to that area of the head is not good.

Nonsurgical Treatment of Microtia

Parents who want to avoid surgery can choose to purchase prosthetic ears for their child instead. Then, the child can apply the prosthetic ears with glue and remove them daily.
Prosthetic ears help children avoid surgery. They can come off, however, causing embarrassment. They may also irritate skin.

Long-term Prognosis of Microtia

Most children born with microtia will not have associated long term medical issues. The goal of our multidisciplinary treatment approach is to achieve optimal hearing and cosmetic outcomes to maximize function and appearance.

Why Choose UPMC Children's Hospital for Craniofacial Care?

While this condition is usually not medically serious and is never life-threatening, it's still important for a doctor to evaluate it. The Cleft-Craniofacial Center combines multiple specialists under one program to ensure that your child receives comprehensive care.

Contact Us

Meet our team at UPMC Children's Hospital of Pittsburgh's Cleft-Craniofacial Center and learn about our treatment options, or contact UPMC Children's Hospital of Pittsburgh at 412-692-8650.