ABSTRACTThe underlying mechanism responsible for bone resorption in chronic otitis media with or without cholesteatoma is not sufficiently well documented. Certain areas in the middle ear are affected more often than others. The most frequent site of bony erosion in the ossicular chain is the long process of the incus.The mineral content of the ossicular chain was investigated with a clinical radiologic technique (polytomography). The findings were correlated with chemical measurements of the mineral content in normal and diseased ossicles. A poor correlation between the radiologic findings and the chemical assessment was found. The mineral content of ossicles obtained from ears with chronic otitis was similar to that of specimens obtained from healthy middle ears. The findings indicate that the demineralization process seems to be localized to a narrow zone of the ossicle and that this zone cannot be adequately visualized by standard radiologic techniques.