What is Anotia?
Anotia is a very rare congenital ear defect marked by the complete absence of the external part of the ear in an infant. Anotia can be mistaken for Microtia, which is also a similar ear defect, but in this condition the infant who is born with a small ear or with partial absence of the ear; whereas babies who are born with Anotia do not have an external ear at all. Microtia is classified into four categories. Anotia is type IV Microtia where the external ear completely fails to develop.
Treatment of Anotia consists of surgery and counseling the child/patient.
Causes of Anotia
The exact cause of Anotia is not clear. It is thought that genetic mutation may cause disruption of the normal growth of the ears causing Anotia. Anotia is thought to occur due to non-development or an abnormal development of the external ear during pregnancy. The signals which are responsible for growth of the ear get disrupted leading to failure of development of external ear. The exact cause why this happens is not known.
There are also certain environmental factors, which are thought to lead to Anotia. Pregnant women using certain medicines such as thalidomide are at a higher risk for having a baby with Anotia.
Sometimes, Anotia can be found along with certain congenital diseases such as: Goldenhar Syndrome, Treacher-Collins Syndrome and Ablepharon-macrostomia Syndrome.
Signs & Symptoms of Anotia
The signs and symptoms of Anotia is obvious where the patient has complete absence of the ear and this is the primary symptom of this congenital defect. Patient can also have other ear related disorders including deafness with Anotia.
Diagnosis of Anotia
Physical examination is sufficient for diagnosis of Anotia. Some patients can also suffer from hearing loss. Thorough evaluation should be done of this condition, as it helps in detecting other associated disorders. The initial 5 to 7 weeks of pregnancy are the most important period of fetal development. During this period, the fetus can also develop certain thyroid disorders, which can hinder the normal development of the ears.
Prenatal diagnosis can be done to ascertain if the fetus is developing normally. It is important to diagnose any congenital problem, which can cause Anotia rather than checking only the development of the ears of the fetus.
Treatment for Anotia
Some reconstructive techniques help in certain ear malformations; however, Anotia is not just an aesthetic problem as the children having Anotia can also have different ear related disorders including deafness. For these patients, treatment of Anotia consists of surgery to correct and manage Anotia. During the surgery, the surgeon surgically enhances the auditory system of the patient and reconstructs the malformed ear.
Bone Anchored Hearing Aid (BAHA) is an apparatus, which is implanted and transmits sound via direct bone conduction. Children who have isolated type unilateral Anotia with deafness can benefit with this corrective treatment.
A medical technique called auricular reconstruction is commonly used for treating Anotia. It helps in restoring the appearance of the external ear in Anotia.
Complications of Anotia
Complications can occur after corrective surgery is done for Anotia and these include: Infections, poor healing of the wound and excessive scarring. However, surgery itself for Anotia does not usually cause any unfavorable effects in the normal development of a child.
Prevention of Anotia
It is not exactly possible to prevent Anotia, as the cause of this defect is not known. However, pregnant women should avoid the use of the drug thalidomide to prevent and decrease the risk of her baby being born with Anotia.
Prognosis of Anotia
Prognosis of Anotia differs from one patient to another. Prognosis is good if the child is treated in his/her early childhood. Children should also be counseled regarding this abnormality and should be encouraged to participate in normal social activities as much as possible. It is important to start treatment of Anotia as early as possible. With proper treatment at the right time, children born with Anotia can lead a fairly normal life.