Improvement in bone conduction threshold after tympanoplasty.

OBJECTIVE: To investigate the causes of bone conduction threshold impairment associated with middle ear pathoses and the factors influencing improvement in bone conduction threshold after tympanoplasty. STUDY DESIGN AND SETTING: The records of 98 consecutive patients with unilateral chronic otitis media who underwent tympanoplasty were reviewed. Pre-operatively, 15 dB or more depression of bone conduction threshold at least in 2 frequencies between 500 and 6000 Hz was considered to be significant. Similarly in the postoperative period, 15 dB or more improvement of bone conduction threshold at least in 2 frequencies between 500 and 6000 Hz was regarded as significant. RESULTS: Twelve (12.5%) of 98 cases were found to have depressed bone conduction threshold; 6 of 12 cases had improved bone conduction threshold after tympanoplasty. CONCLUSION: In cases with cholesteatoma and extensive middle ear disease, successful results could be achieved after tympanoplasty disregarding the air-bone gap and deteriorated bone conduction threshold. SIGNIFICANCE: Bone conduction threshold may improve after tympanoplasty.