Late post-operative hearing results correlated with the severity of tissue changes in ears with chronic otitis media

Late hearing results in 627 ears (574 patients) operated on radically for chronic otitis media are presented. Clinically, the ears were followed-up annually for 5-14 years. The results are correlated with the severity of histopathological changes in the tympanic cavity and in the mastoid air-cell system and also with the management of the tympanic mucosa and ossicular chain at operation. The mean post-operative air-bone gap was significantly better in ears with mild histopathological changes than in ears with severe histopathological changes in the middle ear (17.0 db./33.1 db.; p less than 0.001) or mastoid (29.0 db./34.2 db.; p less than 0.01) at operation. The difference in hearing results in favour of the former group was more significant in ears in which the tympanic mucosa had been saved at operation (p less than 0.01/p less than 0.001) than in ears in which the mucosa had been removed (p less than 0.05).