Microtia

The term external ear malformation both functional and non-interfering abnormalities such as protruding ears and pronounced pinna changes are summarized up to the complete absence of the pinna. As part of the face the ear belongs to a highlighted region of the body, whose unusual for family life, the profession and the social integration can have meaning.

Epidemiology / etiology

A higher grade microtia occurs in the western population in 0.76 to 2.35 cases per 10,000 births. Taking the current birth rate based about 100 to 150 new cases per year are added in Germany.

In general, the abnormality occurs in isolation. In 20 to 30% of cases it occurs in combination with other malformations such as Gesichtshypoplasie, cleft lip and cleft palate, internal malformations, cognitive impairment or in the context of genetic syndromes. The most common associated with microtia syndromes are the Goldenhar syndrome ( hemifacial microsomia ) and the Franceschetti syndrome.

The causes hemorrhagic events in early pregnancy, gestational diabetes and genetic causes are discussed. Further studies in this field are still pending. Familial clustering observed in individual cases, here is usually an autosomal dominant inheritance with variable penetrance based. The vast majority, however, occurs sporadically. Most authors consider the isolated microtia a minimal variant of hemifacial microsomia. The etiology is probably multifactorial with an underlying genetic probability of triggering effect external factors such as bleeding.

Classification

With the division of the external ear malformations three levels are distinguished.

• When dysplasia ° 1 most anatomical structures of the ear are present. These include, inter alia, protruding ears ( apostasis otum ), cup ear cup ear ° ° I and II
• When dysplasia ° 2, only a few structures of the normal auricle are present. These include, inter alia, cup ear ° III and the mini ear.
• When dysplasia ° 3 normal ear structures are virtually non-existent, there exist only rudiments. These include, inter alia, microtia ° III, anotia and dystopia.

Diagnostics

People with microtia should be interdisciplinary advice and treated early. Here, otolaryngologists, Child and Adolescent Physicians, Phoniater and pediatric audiologists and, where appropriate geneticist and maxillo- facial surgeons should be involved. Anamestisch a familial incidence and harmful effects should be obtained in early pregnancy. In the familial clustering idea in human genetics is recommended to estimate the probability of occurrence at other children can. A computed tomography for the assessment of middle ear structures is often in the 10th year, usually during the first hospitalization, performed.

Language development

According to current doctrine, the spoken language is to pass undisturbed on the healthy side with a unilateral conductive hearing block and normal hearing. Therefore, the non-affected side must be checked regularly specialist doctors and conductive or sensorineural hearing loss must be treated quickly and consistently. Children with bilateral malformations or both sides sound conduction block need rapidly after birth acoustic amplification. To this end, the children are first supplied with a headband bone conduction hearing aid, in the 4th year of life can then bone-anchored device ( BAHA ) are used. During the implantation of the bone anchor is to make sure that they are not introduced too close to the ear rudiment in order not to aggravate later aesthetic reconstruction scars.

Therapy

Ohrmuscheldysplasien ° I can be treated by editing existing tissue, for example by Otopexie. Ohrmuscheldysplasien higher level require the use of sliding sculptures, grafts or implants such as the body's own cartilage or plastic. The target is a natural-looking reconstruction that corresponds to the shape of the opposite side.

The surgical construction of a malformed ear with autologous cartilage occurs in two to three steps at intervals of three months. Endogenous rib cartilage is the material that is currently available with the world's greatest experiences.

Alternatively, the surgical construction of a malformed ear with implants made ​​of plastic is possible. The custom-moldable plastic implants are covered with a flap of tissue from the temple area and free skin grafts. The operation can frequently be carried out in one step, a removal of rib cartilage is not necessary. The best long-term results have been achieved with implants made ​​of porous polyethylene that come since the 1980s, used to be produced industrially and are approved for surgical use.

Dysplasia ° III ( microtia )