What is microtia?
Microtia is the Latin word for ‘little ear’ and is used to describe ears that are smaller in size or deformed at birth. Affecting around 1 in 6,000 babies, the fault occurs during the first trimester of pregnancy.
Microtia can be barely noticeable in some children but in others no ear develops at all – this is known as anotia.
In around 10% of cases, it affects both ears but more commonly just one and often the right ear. Microtia tends to affect boys more than girls.
Microtia is often linked to problems with the ear canal/middle ear which causes hearing problems – this is known as atresia. However, the inner ear is generally unaffected, so despite issues with the outer and middle ear, children with microtia can have some of their hearing restored.
For those children with unilateral microtia, the hearing in the other ear is usually fine. Children with bilateral microtia will need hearing aids to help them develop speech.
Types of microtia
There are four grades of microtia:
This is the mildest form of microtia. The ear will be a normal shape but smaller than would be expected.
Grade 2 microtia results in a partial formation of the ear but is often accompanied by underdeveloped or missing ear canals which affects hearing.
This is the most common type of microtia and is characterised by the absence of the ear except for a small peanut shaped ear lobe. In Grade 3 cases, the ear canal and the ear drum are usually not present.
Grade 4 microtia denotes the complete absence of the ear and is actually known as anotia, fortunately it is rare.
Causes of microtia
No one knows the exact cause of microtia but there are several theories about what can increase the risk of it developing in the first trimester. It is unlikely, in most cases, that it is as a result of a mother’s behaviour during pregnancy.
- Even if mum or dad or both have microtia, it is not necessarily passed on to their children and it can also skip a generation. Having said that, no specific gene has been identified as the one responsible for microtia.
- Microtia can be linked to linked to conditions such as Treacher Collins syndrome which affect development.
- Some theories believe that interruptions to blood supply in the area can hold back the development of the ear, likewise drops in oxygen levels.
- Fetal Alcohol Syndrome or drug abuse and some acne medications have been known to cause microtia in some babies.
- Mothers with diabetes are also at a higher risk of their child developing microtia.
Treatment for microtia
Following a diagnosis of microtia, your child’s hearing will be closely monitored. They will also be monitored for health issues connected to microtia, such as kidney abnormalities, issues with bone growth around the jaw and neck and snoring or breathing difficulties.
Depending on the severity of any hearing loss, your child may require hearing aids or surgery to repair any damage to the ear. Your child may also benefit from speech and language therapy.
For children with more severe forms of microtia, reconstructive surgery is an option when they are older. One of the more common forms of surgery is to create an ear from rib cartilage although synthetic material has been used in some clinics.
Surgeries for microtia are usually performed on older children (eight to 10 years), as there’s more cartilage available to graft and the ears are at 90% of their adult growth.
Prosthetic external ear
If surgery isn’t an option, then your child could wear a prosthetic ear made from silicone. They can be attached with a surgically implanted anchor or using an adhesive and can look very realistic.
Surgically implanted hearing devices
If hearing aids are not sufficient, your child may benefit from a surgically implanted hearing device such as a cochlear implant, a bone conduction implant or a middle ear implant.
There is no specific cause for microtia but there are several theories on what causes it or raises the chances of it occurring during pregnancy.
No specific genetic link has been found that relates to microtia, however parents with the condition have had children with microtia.
Yes it can, but it can also skip a generation.
Yes, in some case microtia can affect hearing but that will depend on the grade/severity of the condition and whether it is in one or both ears.