What is microtia?

Microtia is a condition in which one or both ears failed to form or only partially formed during fetal development. Most commonly, children with microtia are born without an ear canal and only a small remnant of atypical cartilage, which may be positioned abnormally on the face.

What causes microtia?

Many children with microtia also have a condition called hemifacial microsomia. The causes of microtia and hemifacial microsomia are not known; the leading theory is that an abnormality or injury to an artery in the head during fetal development leads to abnormal development of the affected structures. Most cases of microtia or hemifacial microsomia are not genetic or inherited, though microtia may be associated with certain syndromes.

What are the symptoms of microtia?

Children with microtia have an obvious deformity of their external ear. In addition, they may have an absent external ear canal and an absent or abnormal middle ear. These conditions result in hearing loss in the affected ear. Typically, children with microtia still have the nerves needed to hear on the affected side, so hearing aids are helpful. Children with hearing loss in one ear can hear, but often have difficulty locating sound sources. 

How are patients with microtia evaluated?

It is critical for patients with microtia to be evaluated by an audiologist and a pediatric ENT specialist to confirm that they have hearing in the unaffected ear. Ear infections and other conditions that may affect hearing in the normal ear must be treated. Patients with unilateral microtia may benefit from hearing aids, and patients with bilateral involvement need them to learn to speak normally. 

Patients who have microtia as a result of a more significant case of hemifacial microsomia require a coordinated team of specialists, including:

• Plastic surgeon
• ENT specialist
• Pediatrician
• Geneticist
• Ophthalmologist
• Dentist
• Orthodontist
• Audiologist
• Speech therapist
• Social worker

All these specialists will evaluate your child and coordinate a comprehensive care plan.

How is microtia treated?

The first priority in microtia treatment is to make sure children can hear well enough to learn to speak. An audiologist and pediatric ENT specialist may assist with this process. Most children wear a bone conduction hearing aid that is held in place with a soft elastic band.

Bone-Anchored Hearing Aid

When children get older, they may be a candidate for a bone-anchored hearing aid where an implant is placed into the bone behind the affected ear. This enables the use of the hearing aid without placing anything inside of the ear.  This procedure should be discussed with a plastic surgeon. If performed before an ear reconstruction surgery, it may increase the risk of complications or compromise the outcome of the ear reconstruction.

Ear Construction

Most children with microtia can have an ear created for them in early childhood. Children must be old enough to have sufficient cartilage in the ribs to create an entire ear, and emotionally mature enough to undergo the process. Synthetic materials can sometimes be used for ear reconstruction.

In most cases of microtia, an ear can be reconstructed in two operations. Many children benefit from a small follow-up operation to maximize the result. More complex cases require three or four operations to complete construction of a new ear.

• The first operation in microtia surgery requires the surgeon to carve an ear from rib cartilage and place it where the missing ear should be located.
• The second operation is performed six to 12 months later, and involves elevating the ear so that it sticks out from the head. This is done using tissue taken from the scalp (the TPF flap) or behind the ear, and a skin graft taken from another location.

Most children with microtia will require additional surgery to help them hear.

Some children may be candidates for canalplasty, or creation of a new ear canal. This is performed by an otology specialist, who can help determine if the child is a candidate for this surgery.

These procedures should be discussed with a plastic surgeon. If they are performed before ear reconstruction surgery, they may increase the risk of complications or compromise the outcome of ear reconstruction.