1989 Volume 82 Issue 12 Pages 1727-1734
Postoperative hearing was investigated in 383 ears after tympanoplasty performed during the period from 1976 to 1988, especially with the intention of analyzing the influence of mastoidectomy on postoperative inner ear disorders.
At speech frequency ranges, postoperative hearing test results were satisfactory in 95% of ears after type I tympanoplasty without mastoidectomy, and in 74% of ears after types I, III and IV tympanoplasty with mastoidectomy.
Mastoidectomy, posterior and anterior tympanotomy were performed only with the air drill from 1976-4985. From 1986 to 1988, an operative procedure just around the ossicles was performed carefully with small gouges after mastoidectomy with an air drill. Although the postoperative hearing results were almost the same with and without mastoidectomy with respect to speech frequencies from 1976 to 1985, hearing thresholds at high frequency ranges were impaired in many ears after mastoidectomy. However, after a change in the mastoidectomy technique (1986-1988), hearing impairment was rarely observed at high frequency ranges in the ears after mastoidectomy.
The results suggest that mastoidectomy with an air drill should be performed very carefully and small gouges should be used more frequently to prevent inner ear disorders by careless use of the air drill.
