What is Microtia?
Microtia means "small ear” and occurs in approximately 1:6000-12,000 births. Microtia is congenital (at birth) and can affect one or both ears. Any child born with microtia should be evaluated at a Craniofacial Center to rule out other conditions like hemifacial microsomia or Treacher Collins syndrome.
Causes of Microtia
Currently no specific gene has been identified to cause this condition. Several medications have been associated with microtia, but this is hard to prove. One hypothesis is that a small blood vessel (stapedial artery) obliterates or bleeds near the developing ear, causing decreased flow of cells important in ear development.
Children can usually hear even though the outer ear is not present, as the inner ear is normally formed. Most children lose about 40-50% of their hearing. However, children do well with relatively normal speech development because the contralateral ear is normal. The main problem children with microtia have is in localizing sound.
Types of Microtia
Microtia is divided into four classifications based on how the ear is affected:
- Grade 1: This is the mildest form, with the affected ear being smaller than normal.
- Grade 2: In this type of microtia, some of the normal features of the outer ear are missing.
- Grade 3: This is the most common form of microtia where the Here, the affected ear consists simply of a vertical appendage of skin and cartilage.
- Anotia: This is the most severe type of microtia with complete absence of the ear.
Treatment for Microtia
Your child will be seen by the craniofacial team for regular hearing checks. We also recommend the parents be aware of any signs of infection on the normal side, as keeping the opposite functional eardrum healthy is very important.
Treatment of microtia involves constructing of the outer ear. Two options are available to build the ear, a synthetic implant (MEDPOR) or your child's own rib (autologous reconstruction). The advantages and disadvantages of each method will be discussed during the office visit.
Surgical procedures usually begin when your child is 6-8 years old for two reasons: the ear has reached 85-90% of its adult size and your child has enough rib cartilage for surgeons to use to construct the ear. Ears are reconstructed over a series of two to three operations.