In a 20 year period from 1977 to 1998 at Ehime University School of Medicine, 36 patients with clinical otosclerosis, including three bilateral cases, were operated on using one of the three types of surgical procedures; total stapedectomy (T-SDE) in 12, partial stapedectomy (P-SDE) in 14, and stapedotomy (STO) in 13 ears. Mean improvements in air and bone conduction hearing levels were 28.0dB and 9.7dB, respectively.
The P-SDE and STO groups showed the best improvement of air conduction hearing at higher frequencies, while the T-SDE group showed the best improvement of bone conduction hearing at 1000 and 2000Hz. The percentage of ears in which the postoperative air-bone gap was within 10dB were 83% in the T-SDE group, 86% in the P-SDE group and 77% in the STO group. In 9 of 10 ears followed up for more than 2 years, postoperative hearing remained unchanged.
