Forty ears with auditory ossicular malformations without deformities of the external meatus, were treated at the Department of otolaryngology, Hokkaido University Hospital over a 15-year period. The pathological conditions were classified according to the surgical findings. The classification results were as follows. Absence of the incudo-stapedial (I-S) joint was seen in 19 ears (47.5%), fixation of the malleus and/or incus in 2 ears (5%), fixation of the stapes in 9 ears (22.5%), and absence of oval window was seen in 4 ears (10%). Ossicular reconstructions were performed in 36 ears and exploratory tympanotomy without ossicular reconstruction was performed in the other 4 ears. The modified type method was performed in 15 ears and the modified type IV method was performed in 8 ears. The small-fenestra stapedectomy was performed in 10 ears and the total or partial stapedectomy was performed in 3 ears. We also evaluated hearing results in 30 ears more than six months after the operation. Hearing improvement after the operation was observed in 93. 3%(28 ears) of the cases.
