Pathology of the ossicular chain in various chronic middle ear diseases

Abstract

In a collection of 1100 operated human ears, 426 of which had cholesteatoma and 674 had not, the various defects of the ossicular chain are described and related to the nature of the disease and the site of perforation. Marked differences exist between the various diseases and the frequency of the individual ossicular defects or combinations of defects. Defects of the head of the malleus and of the body of incus were found exclusively in cholesteatomas, most often those affecting the attic. Isolated defects of the malleus handle were most common in cholesteatoma of the pars tensa and in total perforations. Defects of the long process of the incus occurred in 74-88% of cholesteatomatous diseases; defects of the stapedial arch occurred in 47% of ears with sinus cholesteatoma. In granulating otitis without cholesteatoma and in sequelae to otitis, there was less ossicular pathology; 57% of these ears had an intact ossicular chain. Total or posterior perforations were associated with pathology of the ossicles more often than inferior or anterior perforations. All cases with destruction of the body of the incus and the head of the malleus showed squamous epithelium in close relation to the ossicular defect, indicating a marked, presumably enzymatic influence by the squamous epithelium upon the bone resorption.