The common cause of microtia is not necessarily due to a mothers prenatal activities such as caffeine intake, alcohol, etc. No genetic traits have been conclusively identified. There are strong medications that can produce microtia (see link towards the end of this write-up of more information).
How to choose the right treatment if treatment is indeed recommended is based on the level of microtia. These levels are based on the the following description:
The smallness of the ear is slight and the external ear canal can be small but still functional.
Partial external ear structure and closed off or obstructed external ear canal that results in a loss of hearing.
Insignificant external ear structure, with no external ear canal and or ear drum.
Non existant ear.
What causes Microtia?
How is Microtia treated?
Specialized surgical teams perform hearing tests, examination of temporal bones in an effort to trace facial nerve and to determine the lever of deformity to the different areas of the ear structure. X-rays are also taken to factor in facial structures and bite formation.
Multi-stage process to harvest cartilage that will be used in the reconstruction effort is conducted among other things. It may be neccessary to move the framework of the existing area to be treated to achieve a more natural appearance (see link at the end of this write-up for more information). Also if neccessary a neuro-otologist would reconstruct the canal and line with skin graft achieving better hearing.
Highly tissue compatible material called the Medpor alternative is used in the reconstruction of the auricular part of the ear.
General Microtia Information
What is Microtia?
Microtia is a malformed ear that is undersized (otia meaning “small ear”) due to a congenital birth defect.