MICROTIA

Microtia is a congenital ear deformity where the outer ear is underdeveloped or absent (anotia). Occurring in approximately 1 in 6,000 to 12,000 births, it often affects the right ear and is frequently accompanied by aural atresia (absence of an ear canal), leading to conductive hearing loss. While the diagnosis can be overwhelming, the inner ear is usually healthy, making successful reconstruction and hearing restoration possible.

What is microtia?

The term "microtia" is derived from the Latin words micro (small) and otia (ear). It is a congenital condition that develops during the first trimester of pregnancy. While it can occur as part of a spectrum like Hemifacial Microsomia or Treacher Collins Syndrome, in most cases, it is a random, isolated event.

Microtia occurs in approximately 1 in 6,000 to 12,000 births. It is more common in males and often affects the right ear more than the left.

The Four Grades of Microtia

Medical professionals classify the severity of the ear deformity into four grades. Dr. Bonilla evaluates each child individually to determine the best surgical approach for their specific grade.

Microtia is classified into four grades:

• Grade 1: The ear is smaller than normal (microtic) but retains most normal features. The ear canal is often present but may be narrow (stenosis).
• Grade 2: The ear is partially formed, usually with the upper half underdeveloped. This is often referred to as "Conchal Type" microtia.
• Grade 3: The most common form (Lobule Type). The ear consists of a vertical peanut-shaped remnant of skin and cartilage. There is typically no ear canal (atresia).
• Grade 4 (Anotia): The complete absence of the external ear structure.

Causes & Risk Factors?

Parents often ask, "Did I cause this?" The answer is no. Current research suggests that microtia is largely a random occurrence caused by a temporary disruption of blood flow (possibly via the stapedial artery) during fetal development. It is rarely genetic; the risk of passing it to future children is approximately 5%. It is not caused by the mother's diet, stress, or activities during pregnancy.

Aural Atresia & Hearing Loss

Microtia mainly affects the outer ear, but it is often linked to Aural Atresia, the absence of an ear canal. This results in "conductive hearing loss," where sound cannot reach the middle ear. However, the inner ear (cochlea) and hearing nerve are usually perfectly normal.

*The Solution: Dr. Bonilla coordinates closely with audiologists to manage hearing. Treatment options range from BAHA (Bone Anchored Hearing Aids) on a softband for infants to surgical canal reconstruction (Atresiaplasty) for older children.

Pediatric Ear Reconstruction:
The Rib Cartilage Standard

Dr. Arturo Bonilla utilizes the autologous rib cartilage technique, widely considered the "Gold Standard" for pediatric ear reconstruction. Unlike synthetic plastic implants (Medpor), which carry lifelong risks of infection, extrusion, and fracture, living rib cartilage:

-Grows with the child: Ensuring the new ear remains symmetrical as the patient ages.

-Heals naturally: Since it is the patient's own tissue, there is no risk of rejection.

-Withstands trauma: Children can play sports and lead active lives without fear of damaging a plastic implant.

Frequently Asked Questions

Is microtia surgery cosmetic?

No. Microtia reconstruction is reconstructive surgery intended to correct a congenital deformity and improve quality of life. Therefore, it is typically covered by insurance plans.

At what age should microtia surgery be performed?

Dr. Bonilla recommends beginning reconstruction between 6 and 9 years of age. At this time, the child has sufficient rib cartilage to craft a detailed ear framework, and the "normal" ear has reached near-adult size, allowing for perfect symmetry.

Can microtia be detected on an ultrasound?

Microtia is often missed on prenatal ultrasounds because technicians focus on vital organs like the heart and kidneys. Many parents only discover the condition at birth.

Is microtia hereditary?

Microtia is usually not inherited, but in rare cases, there may be a genetic link or family history of ear anomalies. It is recommended to seek a Geneticist specialist for a complete patient and family assessment for future risks.

Can microtia occur with other conditions?

Yes, microtia may be associated with conditions like hemifacial microsomia, Treacher-Collins syndrome and Goldenhar syndrome. However, many children with microtia are otherwise healthy.

What tests are needed after birth?

While the newborn with microtia is still in the hospital, a newborn hearing screening is always performed. Usually the baby with microtia will pass on the normal side and fail on the microtia side. This does not mean the patient is deaf. It just means that there is some type of hearing loss that needs to be further evaluated. Once the patient is discharged from the hospital, an auditory brainstem response test (ABR) is recommended to evaluate in more detail the function of the auditory or hearing nerve. Most patients have a normal hearing nerve, even on the side of the microtia. This means that sound is just muffled on that side without deafness. As stated above, a CT scan of the ears is performed at a later age (usually 4-5 years of age) to evaluate the anatomy of the outer, middle and inner ears to determine if the child is a possible candidate for opening up the ear canal. An audiological evaluation is also very important. A full ENT evaluation is also recommended.

How is microtia diagnosed?

Microtia is usually easily diagnosed at birth. When the microtia is very minor (Grade 1 microtia), it may be more difficult to diagnose. Imaging studies like a CT scan may be used to evaluate the inner ear structures and determine candidacy for hearing improvement via bone-conduction hearing aids or surgery at a later age.

When should my child see a microtia specialist?

Dr. Bonilla recommends consulting a microtia specialist as early as the day of birth to help parents understand the condition and outline a plan for hearing and reconstructive care. During this time, there is much stress from the parents and this is a perfect time to let the parents know that everything will be ok and that their child is not deaf. This is also a good time to give the parents a general plan for the management of the microtia as well as management of the hearing.

Dr. Bonilla has been treating pediatric microtia patients for over 30 years.

What are the treatment options for microtia?

Which 3D reconstruction method is best?

The best method depends on your child’s anatomy, medical history, and your surgeon’s expertise. Rib cartilage surgery (the most common and gold-standard) is natural and long-lasting, while Medpor / Supor offers earlier reconstruction but with different risks such as fracture or exposure of the new ear for the rest of the patient's life. Surgeon experience is absolutely critical using the above techniques in order to avoid a lifetime of dealing with a poor aesthetic result.

Can children with microtia hear?

Children with microtia usually have moderate to severe conductive hearing loss, especially if they also have aural atresia. However, their inner ear (cochlea) function is usually normal, and hearing can be improved with hearing devices or surgery.

What hearing devices can help?

Bone conduction devices such as a BAHA softband can immediately improve the hearing via bone-conduction on the skull. Later, the more invasive surgical hearing options are available like the bone anchored hearing aid systems by Cochlear, Oticon, Med-El, usually during the microtia reconstruction. Depending on the result of the CT scan of the ears and on the experience of the ear canal surgeon, the ear canal may also be opened (atresiaplasty).

Can ear canal surgery restore hearing?

In some children with favorable anatomy, atresia repair surgery can create a functioning ear canal and significantly improve hearing. A CT scan helps determine if this is a good option. It is crucial to be evaluated by a very experienced ear canal surgeon in order to avoid damage to the facial nerve, and to decrease the risks of ear canal scarring, etc…

Is microtia associated with psychological effects?

It is important to inform the parents of children with microtia that their lives can be perfectly normal, with or without any type of surgical intervention. Parental confidence is crucial. Dr. Bonilla always gives parents the first option of “doing no surgery at all”. It is common to be pressured to operate on all of these children with microtia, but it should be a decision of the patient as well.

It is not uncommon to receive bullying at school during school age, causing the children to lose self confidence. With early family support and positive reinforcement, the children will do very well and live normal lives without restrictions. Reconstructive surgery with a good result can also improve self-esteem.

How do I support my child emotionally or psychologically?

Encourage open conversations, connect with support groups, and consult with child psychologists or counselors if needed. Highlight your child’s strengths and talents beyond their appearance. It is important to see the “parent's guide to a child with microtia”.

Can children with microtia attend school and live normal lives?

Absolutely. With proper hearing support and care, children with microtia can thrive academically, socially, and physically like any other child.