Late changes in hearing results after mastoid obliteration with tympanoplasty.

Hearing results are presented for 627 ears with chronic otitis media that were operated on radically and obliterated (Palva flap) and in which a tympanoplasty was performed. The ears were examined annually for five to 14 years (mean, 8.8 years). The long-term improvement (five to 14 years after the surgery) was the greatest in ears with an intact ossicular chain and in ears with ossicular reconstruction using autograft or homograft ossicles or autogenous cortical bone columellae. As a whole, the early (one year after the operation) improvement in the air-bone gap was 8.0 dB when compared with the preoperative gap and the late deterioration in gap after the first year was 6.0 dB. To detect the late changes in hearing results, the ears operated on must be followed up for a least five to ten years.