Microtia is an incomplete or underdeveloped ear. It literally comes from the words “micro” (small) and “otia” (ear). Microtia may affect one side only (unilateral) or affect both ears (bilateral).
What is aural atresia?
Aural atresia is the absence or closure of the ear canal. Many microtia patients also have atresia as the outer ear and ear canal develop at the same time during pregnancy.
What causes microtia?
The exact cause of microtia is still unknown. In the majority of cases, it appears to occur for unknown reasons. Microtia is a congenital birth defect. This means it is present from birth. Microtia occurs when there is a problem with the development of the ear in the embryo. The formation of the ear occurs during the first trimester of pregnancy. Occasionally microtia appears to be genetically inherited, since more than one member of the family can have this condition. However, most of the time it is a once off condition that the child with microtia will not pass on to their own children. It is important for parents to understand that there is no evidence that anything you do during pregnancy causes microtia. One theory is that it may be caused by a lack of blood supply to the ear of the developing embryo. Another suggests that certain cells that form the ear might have difficulty migrating to their final normal location while the embryo is developing.
How common is microtia?
In Australia, there is very little statistical information available on microtia and atresia. Even worldwide, quoted incidence rates vary from source to source. It is generally accepted that microtia occurs in about 1 in every 6,000 births worldwide. Incidence varies widely due to ethnicity, with some populations having rates as high as 1 in every 1,000 – 2,000 births, and others as low as 1 in every 15,000 – 20,000 births. Microtia is more common in males. It can affect one ear (unilateral) or both ears (bilateral). It occurs unilaterally in 90% of cases. In unilateral cases, it occurs more often on the right side than the left. The chances of having another child with microtia is less than 6%.
How is microtia diagnosed?
If your child has a small, underdeveloped or absent ear, microtia will be obvious at the time of birth. As microtia is not very common, it will depend on your doctor’s experience and knowledge as to whether you are given the diagnosis of “microtia” straight away. Many parents have not been given the name of their child’s condition until several months later or have stumbled upon it themselves. In the majority of cases, microtia occurs in isolation and there are no other medical problems. However, microtia is also known to occur as part of several different syndromes. A syndrome is a collection of signs or symptoms that frequently occur together and are recognised as being related. Your doctor and medical team will diagnose or rule out any syndromes.
Can my child hear out of the affected ear?
Children with microtia and atresia will have some degree of hearing on the affected side(s). Children with microtia can have problems inside their affected ear. If the ear canal is blocked or absent, soundwaves are not able to pass through the ear in the normal way, which will result in reduced hearing in that ear. It is not unusual for the middle ear (which contains the ear drum and tiny ear bones) to be affected. The middle ear bones are sometimes malformed or mishaped. Most children with microtia have a normal inner ear. An audiologist will provide testing and determine your child’s hearing.
How will this affect my child?
Children with unilateral microtia (one side) usually have normal hearing in their other ear, although this must be confirmed by a hearing test as soon as possible. If your child has a unilateral hearing loss (hearing loss on only one side) they can have problems locating the direction where a sound comes from. They may also have trouble hearing when there is a lot of background noise. If your child has bilateral microtia (both ears affected) they will have a significant hearing loss and require hearing assistance.
Will my child’s speech and language be affected?
Having normal hearing in one ear should allow normal speech and language to develop. It is advisable to have regular speech and language assessments to make sure of this. Some children do require extra support for their speech and language. Children with a hearing loss in one ear do not hear well if there is a lot of background noise, therefore they may miss things that are said to them & may not hear all speech sounds. Also, if your child gets a lot of ear infections or has fluid in their ear for an extended period of time, they may have poor hearing during this time and therefore their speech may not develop properly. Optimising a child’s hearing through wearing a hearing device can help overcome the challenges of hearing in one ear.
Can my child get an ear infection in their affected ear?
Yes. Ear infections can occur on the side where there is microtia and atresia. Although there may be no external ear canal or tympanic membrane, there is usually a quite well formed middle ear space which is connected to the back of the nose via the eustachian tube in the same way as a normal ear. It is possible therefore for otitis media (middle ear infection) to occur within this middle ear space.
Otitis media occurring in an atresia ear may cause the same fever and symptoms as in a normal ear. There may be less pain however as there is no sensitive tympanic membrane effected and there isn’t the usual temporary hearing loss that occurs with ear infections.
Diagnosing an ear infection on the microtia and atresia side is difficult as there is no tympanic membrane to examine and visualise. As they can only be diagnosed accurately with a CT scan, if infection on the atresia side is suspected and the other ear is normal, it is likely that at times you and your doctor may have to assume that they have an ear infection in their affected ear and treat it accordingly.
The treatment if ear infection is suspected or confirmed is the same as for infection in a normal ear with painkillers and medicine to reduce fever (Panadol or Nurofen) and antibiotics. These ear infections are no more dangerous than usual otitis media (middle ear infection).
Can my child’s hearing be restored?
It is a common misconception that all it will take to restore your child’s hearing is to make an opening in the skin. Unfortunately the surgery required to restore hearing is much more complicated than that. Typically, surgeons must avoid the facial nerve, drill through solid bone to make a canal, use a skin graft for the canal, and sometimes make an ear drum with tissue grafts. This surgery is technically very difficult, but is possible with a highly experienced surgeon if your child is a candidate and meets certain requirements.
What are the different grades of microtia?
Microtia is graded according to severity. There are three grades of microtia.
Anotia is the name given to the absence of an external ear.
What other medical conditions are associated with microtia?
Microtia can appear on its own or as part of other conditions or syndromes such as Hemifacial Microsomia, Goldenhar Syndrome or Treacher Collins Syndrome (the most common associated syndromes). Your doctor will be able to recognise these conditions upon examining your baby. Some doctors also recommend an ultrasound of your baby’s kidneys as these form at the same time as the ears. If microtia is not related to any of these conditions and occurs in isolation, it should not cause any ongoing problems for your child.
Why wasn’t this picked up during my ultrasound?
There are many abnormalities that can be detected on an ultrasound. Ultrasound technicians usually focus on the major organs unless specifically instructed otherwise. External ears are not routinely checked during an ultrasound and may be difficult to assess.
Will my baby need surgery?
No. There is no surgery required or available for babies who have microtia. Surgical options are available for children over the age of three though.
Can microtia be treated?
1. Do nothing – leave the ear as it is
2. Reconstruction using Rib Graft (cartilage is taken from the ribs)
3. Reconstruction using Medpor (a synthetic material)
4. Have a prosthetic ear made.
Each option has advantages and disadvantages. No option is “perfect”, and there are no right or wrong options. You need to weigh up each option and choose which is right for you and your child.
Is reconstructive surgery complicated?
Ear reconstructive surgery is technically very difficult. Very few surgeons perform ear reconstructions on a regular basis. This is mainly due to the rarity of the condition, but also because of the specific training required. It is therefore important to choose a surgeon who has ongoing experience in this type of surgery and can show you pictures of their results.
How should I raise my child with microtia?
Microtia in itself, is a relatively benign condition and should be treated as such. As long as there are no other associated conditions, these children live a relatively normal life. Raise them as you would any other child and do not make a big deal about their microtia. If you try to hide your child’s ear with hats / long hair etc. your child may think that it is something they should hide and therefore may be more self conscious about their ear.
Help your child to accept this condition and not be unduly self conscious about it. Help your child to focus on their strengths and build their self esteem. As your child gets older, it may be helpful to prepare and practise with your child some simple responses to questions or comments about their ear e.g. “It just didn’t grow properly” or “It was like that when I was born”. You could even let them have a little fun with it – some children have come up with great stories about crocodile attacks etc.
Am I alone?
No. While microtia is not a very common condition, there are many other families and organisations that can help you with information and support. There are links provided on this website to support groups and services. The internet is a wonderful way to connect with other families.