Microtia literally means small ear. Children with this rare condition have a small, abnormally-shaped or absent external ear. Most children have this condition only on one side (unilateral), however it can occur on both sides (bilateral). Typically, microtia only involves the outer ear, but can also cause difficulty hearing and determining the direction of sound. In some cases, a child with microtia will have no hearing in the affected ear, due to the absence of the ear canal. This is called aural atresia. A child with microtia and aural atresia in both ears will be significantly hard of hearing and require a hearing aid. Children with aural atresia typically also have incomplete formation of the small middle ear bones and may lack an eardrum.
Dr. Tahiri specializes in microtia surgery for children. He invites Los Angeles patients and parents to visit his Beverly Hills office to discuss microtia, and recommend surgical treatment.
Microtia is found in children at birth and is usually an isolated condition. In some children, microtia occurs along with other facial abnormalities, such as hemifacial microsomia, which involves the under development of one side of the face, including the ear. In very rare cases, hemifacial microsomia can occur on both sides of the face at once.
Children with Treacher Collins syndrome, a condition that involves the underdevelopment of the lower eyelids, cheekbones and lower jaw, may also have microtia.
Microtia is accompanied by congenital absence or stenosis of the external auditory canal with variable middle ear anomalies this causes a significant conductive hearing loss. Children with unilateral microtia seem to develop normally. Parents usually do not notice a significant difference between their young children and their siblings without microtia. This is the reason why unilateral hearing loss has been undertreated by many otolaryngologists and usually ignored by plastic surgeons treating microtia.
However, when children with microtia are older, and communication becomes more sophisticated, hearing issues become more obvious. Sound localization and hearing comprehension especially in noisy environments become more difficult (13-14).
Patients with microtia tend to turn their unaffected ear in the direction of sound, because the head itself casts a sound shadow, which reduces comprehension in the unturned normal ear.
Once a child is 2.5 years of age, a computer tomography (CT) scan of the temporal bones can allow an otologist to determine if an atresia patient is a possible candidate for a canalplasty. The otologist needs to view the actual scan rather than the radiologist’s report. The Jahrsdorfer 10 point grading scale is commonly used to predict surgical candidacy depending on key features seen on the CT scan.
The treatment of hearing loss by an otologist should be coordinated with the surgeon responsible for the outer ear surgery. Traditionally, atresia repair is done after the costal cartilage ear reconstruction, since almost all otologists perform the ear canal reconstructions through a posterior mastoid skin incision to access the temporal bone. That approach compromises the blood supply of the mastoid skin that is used to cover the cartilage framework. However, prior atresia repair does not jeopardize the success of ear reconstruction using an implant covered by a vascularized fascia flap. With an alloplastic reconstruction, atresia repair is best done before or at the same time as the ear reconstruction as the canal helps with positioning of the reconstructed ear. Also, early atresia repair potentially improves hearing at a critical period of early brain development.
If the patient is not a candidate for atresia repair and a functional canal, a faux-canal can be created at the time of microtia reconstruction.
It is a surgically implantable system for treatment of hearing loss. BAHA stands for Bone Anchoring Hearing Aid.
It has three parts:
A Baha implant enhances natural bone transmission as a pathway for sound to travel to the inner ear, bypassing the external auditory canal and middle ear .
This form of facial clefting (Tessier No. 7) reflects an error in fusion between the embryologic maxillary and mandibular processes. This presents along a spectrum of severity from a subtle transverse cheek crease, or mild lateral oral commissure displacement, to a complete cleft with commissure displacement extending far into the involved cheek. Infants with significant macrostomia may have some difficulty with feeding from non-cleft feeders because of problems with oral seal. Older children with macrostomia may suffer from oral salivary incontinence.
Dr. Tahiri has extensive experience treating microtia. He works closely with other specialists, including Ear, Nose and Throat physicians when hearing aid placement or canal reconstruction is necessary. Because microtia may occur in conjunction with other craniofacial conditions that require reconstruction, our coordinated care means your child receives the comprehensive treatment necessary to accomplish the best outcomes.
After having performed multiple techniques for ear reconstructions, Dr. Tahiri decided to only perform Medpor Ear Reconstruction; technique that was popularized by his colleague and founder of the surgery, Dr. John Reinisch.
In addition to hearing and language screenings, a high resolution, 3D CT scan of the temporal bones is recommended. This test is performed to rule out a benign tumor of the middle ear, known as a cholesteatoma, which is more common in children with aural atresia.
The traditional method of ear reconstruction has utilized an ear framework made from rib cartilage. Refinements of the cartilage procedure over the years have reduced the number of needed surgical stages. However, the amount of required harvested cartilage has increased, pushing back the age of reconstruction until 10 years of age or older. Reconstruction at an older age, and its usual multiple stages, have made microtia reconstruction with autologous cartilage a more arduous physical and psychological endeavor for both children and their parents. If the final cosmetic result of the constructed ear is not ideal, the entire reconstructive journey can be disappointing.
The use of an alloplastic framework covered by a thin temporo-parietal fascia flap offers several advantages over the traditional method of cartilage reconstruction. Since ears reach 85% of adult size by 3.5 years, ear reconstruction can be performed at a younger age since the need for sufficient costal cartilage is not a factor. Other advantages of a fascia covered alloplastic framework over the traditional rib cartilage technique include minimal patient discomfort, single outpatient procedure, and better ear definition and projection.
Candidates for Medpor implant reconstruction include patients with congenital microtia, as well as patients with a traumatic loss of their ear or a prior unsatisfactory ear reconstruction. Patients must have either an intact superficial temporal artery supplying the superficial temporal-parietal fascia or a patent occipital artery supplying the occipital parietal fascia. Free fascia flaps with a radial forearm fascia or a free contralateral TPF flap are possible in the rare case, in which no local arterial fascia flaps are available.
Conditions that would be contraindications for traditional rib reconstruction (low hair line, mastoid scaring, or a previous atresia repair) are not contraindications for Medpor ear reconstruction if the entire implant can be covered with well-vascularized fascia.
The first post-operative appointment occurs at post-op day #2 or #3. The absorptive dressing is removed during this appointment. If fluid is noticed beneath the scalp at that time, it can be easily drained percutaneously with a butterfly needle. The silicone ear splint is left in place for a total of two weeks post-operatively. During that period, the head should be kept dry and patient should not sleep on the side of surgery to avoid pressure on the reconstructed ear.
For young children, parents should sleep with the child to make sure they do not inadvertently turn and sleep on the operated side.
At two weeks post-operatively, the silicone ear mold is removed and the ear and head are washed with shampoo in the office. Parents are shown how to wash it gently with their fingers on a daily fashion. A new silicone ear mold is made for the patient to use at night for the following four months. A light coating of ointment is applied on the ear before applying the ear mold for the next week.
The third post-operative visit occurs after three weeks. Washing can now be done with a gauze pad to encourage removal of the dissolving chromic sutures. Parents are taught how to make the silicone ear mold, which will be worn every night for the following four months (parents are provided with the silicone mold packets). This helps to protect the ear, but more importantly, it helps to maintain the projection of the ear.
It is important there is sufficient hearing during a child’s early years in order to ensure normal speech development. Two types of hearing tests help determine if a child will need a hearing aid:
Patients with bilateral aural atresia, meaning they have hearing loss in both ears, receive bone conduction hearing aids within the first few months of life. In addition, speech therapy will be recommended as soon as a child begins to talk. Older children may receive a bone-anchored hearing aid (BAHA), which works by directly stimulating the inner ear through the bone.