Résumé
BACKGROUND AND OBJECTIVES: The tympanosclerosis is an abnormal deposits of collagen materials on the lamina propria of the tympanic membrane or the middle ear mucosa. It usually appears as a whitish plaque on the tympanic membrane through otoscopic examination. The etiology of tympanosclerosis is not known, but there are some theories that attempt to explain the pathogenesis. The aim of this study is to understand the pathogenesis of tympanosclerosis and to find out the methods to minimize the occurrence of tympanosclerosis after ventilation tube insertion. MATERIALS AND METHODS: Otoscopic examination, impedance and pure tone audiometry were performed on 190 patients (306 ears) with serous otitis media, and on those who have undertaken ventilaton tube insertion from 1990 to 1998 at the otolaryngology department in Hanyang University Hospital. Then, the patients' medical and operative records were reviewed and analyzed in view of location and pathogenesis of tympanosclerosis. RESULTS: Incidence rate of tympanosclerosis was 42.5% in non-cleft patients and 61.9% in congenital cleft and palate patients. The rate increased when larger and heavier tube was used and the middle ear fluid was highly viscous. Most common sites for the development of tympanosclerosis were in the posteroinferior and anteroinferior portions of the tympanic membrane. Tympanosclerosis had little effect on hearing but in severe cases, it caused mild degree of hearing loss. CONCLUSION: We consider that tympanosclerosis is an inevitable result of ventilation tube insertion and its pathogenesis is multifactorial. We found that we can minimize the occurrence of tympanosclerosis by using small and light ventilation tubes, and avoid intraoperative bleeding and minimal mechanical trauma on the tympanic membrane by aspiring the middle ear fluid.