Microtia and Sensory Defects in Growth

Abstract

Microtia is a congenital abnormality of the auricle involving the external auditory canal (EAC) and middle ear structures. The main problems of patients with microtia are severe hearing loss and cosmetic abnormalities of the affected ear. Most patients with microtia have normally formed inner ears and have no sensorineural hearing loss. Therefore, the hearing loss is conductive and dependent on the status of the EAC and abnormalities of the middle ear structures in the affected ear. The relationship between the hearing level and severity of abnormalities in microtia according to Marx’s classification and the middle ear abnormalities that affect hearing according to Jahrsdoerfer’s high-resolution computed tomography (HRCT) scoring system were evaluated. In this analysis, patients with severe abnormality of the auricle did not always experience severe hearing loss. In addition, there was no relationship between the hearing level and total HRCT score. However, atresia or stenosis of the EAC, the formation of oval/round windows, and ossicular development in the middle ear were correlated with the hearing level in patients with microtia. The hearing level ranged from about 60 to 70 dB in the atresia group and from about 54 to 64 dB in the stenosis group. It was reported that “The better developed the auricle in patients with microtia, the better developed middle ear structures”. However, patients with severe developed auricle were not always having severe hearing loss.