Anotia Infant Ear Deformity
Anotia is an ear deformity which is present at birth (congenital) and is characterized by the absence of the entire external part of the ear. Anotia is the most severe (level IV) of the microtia ear deformity which presents as a small and often malformed outer ear. Anotia is a rare condition (affecting one to two infants per 10,000 births) and can occur unilaterally (one ear only), which is most common, or bilaterally (both ears). Unfortunately, this severe baby ear deformity cannot be treated with the Earwell™ Infant Ear Correction System.
While most anotia patients do have middle and internal ear structures, they often experience conductive hearing loss, meaning that sound waves have difficulty traveling through the ear to be heard. Conductive hearing loss is typically a treatable condition which will be addressed during the course of anotia treatment.
What Causes Anotia (Missing Ear)?
The exact cause of the anotia deformity is not entirely clear. In approximately 40% of cases, anotia presents in conjunction with other congenital diseases such as:
- Goldenhar syndrome
- Treacher Collins syndrome
- Ablepharon macrostomia syndrome (AMS)
Anotia occurs during the first trimester of prenatal development, thus external factors are also thought to be contributors to the disruption of normal ear growth, including:
- Maternal diabetes
- Maternal exposure to certain drugs, such as thalidomide
- Recreational drug use during pregnancy
- Maternal diet low in folic acid or carbohydrates
While certain risk factors can and should be avoided, most cases of anotia occur due to a genetic mutation of unknown origin and are not due to any maternal behavior.
Diagnosing and Treating Anotia
Anotia can be diagnosed at birth, as the absence of the ear is immediately recognizable. In some cases, prenatal ultrasounds can lead to early diagnosis. If anotia is identified prenatally, your doctor will likely want to perform additional diagnostic testing to check for other abnormalities that can present in association with anotia, as well as evaluate other organs that develop during the same prenatal time frame as the ears.
Once anotia is diagnosed, a multidisciplinary team of medical specialists will work together to provide treatment. An otolaryngologist will perform an otologic assessment of the internal and middle ear structures to evaluate hearing and develop a treatment plan to restore/improve hearing. A speech pathologist is often recommended to assist with speech development.
Total ear reconstruction (auricular reconstruction) by an experienced plastic surgeon is the standard treatment for anotia. This procedure is typically performed between the ages of six and ten to allow for rib cartilage growth (which can be used in grafting the new ear) and to enable the existing ear to reach at least 90% of its mature size. Ear reconstruction for anotia generally occurs in several stages/surgeries.
Most commonly, the first ear reconstruction procedure involves the use of rib cartilage grafting. Cartilage from the patient’s lower rib cage is harvested and shaped to form the new ear. This framework is surgically placed under the skin where the ear would normally grow.
After the graft site has healed, a second procedure is performed to create an earlobe. Next, the ear framework is released from the scalp to allow normal projection from the head. The final stage of reconstruction involves creating a conchal bowl (the center portion of cartilage that leads into the ear canal). Typically, cartilage and skin from the opposite ear is used for this procedure. This does not affect the appearance of the normal ear.
In cases in which rib cartilage cannot be used, ear reconstruction is performed using a synthetic material implanted under the skin. This procedure may be done at an earlier age since it is not dependent on rib cage cartilage growth.
Surgeries may also involve reconstruction of the ear canal if necessary (typically after external reconstruction), as well as implantation of a Bone Anchored Hearing Aid (BAHA) to allow sound waves to be conducted through the skull (bone conduction) in cases where middle ear development is affected.
Prognosis for patients with anotia is generally very good when treated in early childhood. When anotia is an isolated condition, patients can typically lead normal lives after treatment. If you have a child with anotia, we are pleased to refer you to highly skilled, experienced specialists in the field of plastic surgery, otolaryngology, and speech therapy to help you navigate through the process of treatment as smoothly and comfortably as possible.