Microtia and Other Ear Deformities
Congenital ear deformities occur in many different syndromes or alone. The term microtia indicates a small, abnormally shaped or absent external ear. It can occur on one side only (unilateral) or on both sides (bilateral). The unilateral form is much more common, occurring in approximately 90% of patients. It more frequently affects boys and the right ear. Unilateral microtia occurs in approximately one out of 6,000 births and bilateral microtia occurs in one out of 25,000 births.
Repair of congenital microtia requires the coordinated efforts of both a plastic surgeon and an Ear, Nose and Throat (ENT) surgeon. Reconstruction of the microtic ear is usually delayed until the child is 6-10 years old. At that age, cartilage from the rib is harvested to reconstruct the external ear. Several operations may be necessary. Any child born with microtia should be evaluated at a craniofacial center to rule out other conditions. For example, children born with microtia on one side may have a condition called hemifacial microsomia. Children who have both ears affected might have Treacher Collins syndrome or bifacial microsomia.
In addition, testing for hearing in both ears is indicated, using brain stem evoked response audiometry (BERA). This testing must be done early to determine the adequacy of hearing in the “normal” ear, as well as to confirm whether it is really normal.
Surgical correction over the last twenty years has been dominated by a technique by Dr. Burt Brent from California. This technique is based on a four-stage procedure that is started at 6-8 years of age. The first stage consists of fashioning the outer ear construct from rib cartilage. This stage requires the largest surgical procedure and an overnight hospital stay. The second stage consists of elevating the ear frame off the skull to give the ear projection. This is usually done with a full thickness skin graft taken from the groin or buttocks. This can be done as an outpatient procedure. The third stage consists of making the ear lobe. The last stage consists of making the tragus, or the cartilage around the ear canal. At any of these later stages, small touch ups and changes can also be employed on an outpatient basis. The timing between procedures is usually at least 3 months in order to insure adequate blood supply.
The treatment team includes the following:
- Craniofacial/plastic surgeon
- ENT surgeon
- Speech therapist
- Social therapist
Patient evaluations usually begin early in life, sometime in the first 3 months as the families usually have many questions and are nervous about the deformity. Annual follow-up appointments are necessary until the time of surgery. Computer tomography (CT) scans are required at different intervals to evaluate the internal anatomy of the ear and may be repeated on a regular basis to evaluate growth. If other anomalies are present, different radiographic interventions may be necessary as well as surgery.
Otoplasty is a surgical procedure used to correct prominent ears. The most common cause of prominent ears is lack of an antihelical fold, normally present just inside the rim of the ear. A wide concha or bowl of the ear can also contribute to prominence of the ear.
Psychsocial studies show that children become self-conscious about their appearance at 5-7 years of age, therefore making this the most common time for otoplasty procedures.
Children can typically be treated any time after 5 years of age, when the ear is nearly adult sized. The technique of otoplasty utilizes an incision on the back of the ears that is hidden from view. Through this incision the antihelical fold can be created and the height of the conchal bowl can be reduced. Nicely positioned ears are symmetrical and their rims are between 15 and 20 mm from the side of the head.
The surgery itself is simple and reliable in most cases, providing an expert carries out the operation. Usually the child can go home on the day of surgery.