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Epidemiological study of cholesteatoma in Fukuoka City

Abstract Objective and design: To investigate the pathogenesis of cholesteatoma, we planned to conduct a cohort study. As a first step, we conducted an epidemiological study in Fukuoka City, Japan to determine the incidence of cholesteatoma treated both with and without surgery. We also conducted a case–control study to investigate the pathogenesis of cholesteatoma. Results: The annual incidence of cholesteatoma, including cases treated without surgery, was 6.8–10.0 in a population of 100 000. The results of the case–control study suggested that a past history of otitis media and habitual sniffing caused by a patulous eustachian tube play a role in the pathogenesis of cholesteatoma. Conclusions: The annual incidence of cholesteatoma, including cases treated without surgery, was considered to not be high enough to perform a cohort study. The results of the case–control study suggest that otitis media and habitual sniffing due to a patulous eustachian tube, contribute to the onset of cholesteatoma.