Mastoid pneumatization in cholesteatoma.

Mastoid pneumatization on 134 cases who had ear surgery for cholesteatoma was studied. Bilateral cholesteatoma was found in 14 patients (11%) and unilateral cholesteatoma associated with contralateral retraction pocket was found in 22 (16%). No patients operated on for cholesteatoma had active chronic otitis media in the contralateral ear. Only 1 out of 155 cases operated on for chronic otitis media with a central perforation had a retraction pocket in the contralateral ear and none had cholesteatoma.The size of the mastoid pneumatization in cholesteatoma was smaller than that in chronic otitis media. In the contralateral ear of cholesteatoma which had normal tympanic membrane, the size of the mastoid pneumatization was smaller than in the normal ear. It was, therefore, thought that in cases of unilateral cholesteatoma, the patient suffered from otitis media in both ears in childhood, and the ear was cured while the other continued to inflamme.