Preoperative hearing loss, microorganisms isolated from ear discharge, duration of ear complaints, the ages of patients, surgical treatment and postoperative restoration of hearing were studied in chronic suppurative and cholesteatomatous otitis media with destroyed stapedial superstructure. Pre- and postoperative hearing loss were determined by averaging air-bone gaps of 0.5, 1, and 2kHz.
The following results were obtained.
1) Dehiscence of the stapedial superstructure is more frequently found in cholesteatoma than in chronic suppurative otitis media. The stapedial superstructure was more rapidly destroyed in cholesteatoma.
2) Pseudomonas aeruginosa was isolated with a significantly higher incidence from ear discharge of chronic purulent otitis media.
3) Infection of plural micro-organisms was found to have no significant effects on stapedial destruction.
4) Preoperative audiograms showed air-bone gags of 30dB or more at all frequencies in 42.9% of the patients, and 26.6% of them showed air-bone gaps of 30dB or more at all frequencies except one.
5) Postoperative air-bone gaps were around 30dB in 7 of the 13 radical mastoidectomy ears.
6) Postoperative air-bone gaps were 33.9dB for radical mastoidectomy, 29.0dB for type IV tympanoplasty and 25.8dB for modified type IV tympanoplasty.
