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Ear deformities: microtia, anotia and constricted ear

Congenital ear deformities are abnormal ear shapes and structures that a baby has at birth. They range from very mild forms that are hardly noticeable, all the way to ears that are completely missing.

No one knows for sure what causes ear deformities. Researchers think it is likely a combination of many things that happen while the baby is in the womb.

There are two broad groups of ear deformities:

  • Malformation: These deformities happen when something interferes with how the baby’s ear forms, and some parts of the ear are missing.
  • Deformation: In these deformities, no parts of the ear are missing, but something pulls or pushes them into an abnormal shape and/or position sometime before birth.

Examples of malformations are:

Examples of deformations are:

Ear deformities don’t always fit into neat categories, though. They can have characteristics of more than one type.

What is microtia?

Microtia (my KRO shee uh) is a condition a baby is born with that causes the ear to be smaller than normal. It can happen in both ears, called bilateral microtia, or only one ear, called unilateral microtia. Most of the time, it happens to only one ear, usually to the right ear. It is more common in boys than girls. Experts estimate that between 1 to 5 out of 10,000 babies is born with microtia in the United States each year.

There are four grades or types of microtia:

Type 1: This is the mildest form. Nothing is missing from the ear, and it looks normal except for being smaller than usual. Hearing may not be affected.

Type 2: Some parts of the ear are missing, and the ear is only about half as big as a normal ear. The ear canal, which leads from the outer ear to the middle ear and helps with hearing, may be narrow or closed, a condition called aural atresia (OR-ul eh-TREE-zhuh). There is usually some hearing loss with this type. Type 2 is sometimes called conchal type microtia.

Type 3: This is the most common type of microtia. Most of the outer ear is missing. It is sometimes called peanut ear, because it is shaped like a small peanut with an ear lobe. It also involves aural atresia, with the ear canal and ear drum being missing inside the middle ear. Type 3, also called lobular microtia, causes hearing loss.

Type 4: In this type, the outer ear and middle ear are both completely missing. Type 4 microtia is called anotia (an-NO-she-uh). It is the rarest and most severe type. Babies with anotia have hearing loss. There is no difference between microtia and anotia; anotia is the most severe type of microtia, not a separate condition.

The amount of hearing loss a baby may have depends on how much of the ear canal and middle ear are affected. Often, the degree of abnormality on the outside of the ear is an indicator of how much abnormality to expect inside in the middle ear. If microtia only affects one ear, hearing in the other ear should be normal. Hearing loss with microtia is usually a type called conductive hearing loss. In this type, sound isn’t able to travel from outside the ear to the inner ear. This type can be helped with hearing aids.

What causes microtia?

Like other types of ear deformities, researchers don’t know for sure what causes cases of microtia. It doesn’t seem to be completely related to a family's medical history. Right now, there isn’t a way to prevent it.

Most of the time, microtia happens by itself without any other abnormalities in the baby. Sometimes, it happens as part of a syndrome where there are more abnormalities in other parts of the body. Some of the syndromes that microtia can be a part of include:

  • Treacher Collins (issues with the bones and tissues of the face)
  • Hemifacial microsomia (part of the face is smaller than normal)
  • Goldenhar syndrome (lower half of one side of the face is abnormal, with abnormal growths in the eye)
  • Melnick-Fraser syndrome
  • Nager syndrome
  • Crouzon syndrome
  • CHARGE syndrome
  • Pierre-Robin sequence (read more)

If a baby is born with microtia, doctors will often do tests to check for other issues. For example, a baby’s kidneys develop in the womb at the same time the ears do, so doctors will check the kidneys on ultrasound to see if they look OK.

How is microtia treated?

A baby’s treatment for microtia will depend on how severe it is. A mild case (Type 1) that doesn’t cause hearing loss may not need anything to be done. Ear molding may also be an option for mild microtia.

For more severe cases, plastic surgeons who correct the shape of the ear will work together with doctors who treat hearing loss called otolaryngologists and audiologists. Together, they will make a treatment plan that will give the baby the best possible results in appearance, hearing, learning and social development.

To help with hearing, surgeons may perform an operation to open or widen the ear canal if it is narrowed or closed. Some babies with hearing loss may be fitted with hearing aids. This is important so they can learn how to talk. A speech therapist may also work with the child to help with speaking.

There are many different procedures plastic surgeons can do to improve the ear’s appearance, or to create an ear where there is one missing. These are complex procedures, but the pediatric plastic surgeons at Children’s of Mississippi are experts in determining the best option based on a child’s specific situation.

In general, plastic surgeons can attach a prosthetic (artificial) ear or reshape or build one. To reshape or build an ear, they can use artificial material, tissue from somewhere else on the child’s body, or a combination of both. When a child’s own tissue is used, called autologous tissue, frequently it is cartilage that is taken from the ribs.

The timing for surgery depends on a number of factors. For example, the older the child, the less flexible the outer ear becomes. In many cases, the surgery is done when the child is between 5 and 10 years old. A baby’s ears reach about 90 percent of its full-grown width by the time the child is 5 years old and about 75 percent of its length. Surgery during this period can help the surgeon determine the best way to shape the ear. It also means the child is old enough to communicate with the doctors who are doing the treatment. Depending on how the surgery is done, treatment could require several surgeries over different stages.

Children with microtia/anotia can develop normally and lead happy, healthy and productive lives. This is especially true when they get early care for hearing and speaking. Children who have the condition along with other issues as part of a syndrome will need more care to manage all their additional symptoms.

What is a constricted ear?

A constricted ear, sometimes called a cup ear or lop ear, is an abnormally shaped ear that a baby has at birth. With this condition, the upper part of the ear may look folded forward or down, and the ear is shorter than normal. It may stick out some and be set low on the baby’s head. Constricted ear usually doesn’t cause hearing loss.

Constricted ear can range in severity:

  • Mild: The ear has only a small amount of cupping and is almost normal in height.
  • Moderate: The ear is cupped more, is shorter than normal and sticks out.
  • Severe: The ear is cupped still more, is noticeably shorter than normal, sticks out and is set lower on the head.

Treatment for constricted ear

The mildest forms of the condition may be corrected without surgery using a technique called ear molding. This process takes advantage of the fact that a newborn’s ears are still very flexible and can be reshaped using custom-fitted splints or molds that are worn until the ear holds its new shape. This can take several weeks.

Ear molding is the most successful when it starts before the baby is 2 weeks old. At this age, the baby’s ear is at its most flexible and it will respond to shaping better. In fact, a baby’s ear is the most flexible for about the first week after birth.

Moderate and severe cases of constricted ear will likely require reconstructive surgery. Plastic surgeons may wait until a child is between 4 and 6 years old to do this operation. Pediatric plastic surgeons at Children’s of Mississippi are experts in correcting all types of ear deformities, including constricted ear. They can discuss what surgery may be the best for your child and help you understand what the procedure will involve.

Get help at Children’s of Mississippi

If your child has an abnormally shaped ear, you can schedule an appointment with our Children’s of Mississippi plastic surgery team. They are experts in determining the best way to treat ear deformities and can help you understand all your options. Schedule an appointment online.

Last reviewed 11/7/2025.