[Silence nature of otitis media].

To explore the silence nature of otitis media, the temporal bone slides from 306 ear with various types of otitis media were studied histopathologically under the light microscopy and their case histories were reviewed at the Otopathology Laboratory, the University of Minnesota Otitis Media Research Center U.S.A. The results showed that 80.97% of otitis media cases lacked clinical symptoms in pathologic process. The subnormal function status of the eustachian tube and the low-degree infection in pathologic process of otitis media probably are basic causes of silence nature of otitis media. The anatomic specialty of ventilation/drainage system of middle ear cleft and the inflammatory pathologic change causing obstruction of internal ventilation/drainage system and leading to the retention of effusion in posterior areas of middle ear cleft may be are important factors for the development of obstinate pathologic change and silence nature of pathologic process of chronic otitis media.