[Congenital auditory ossicle malformation without external ear abnormality].

In 29 ears of 24 patients with auditory ossicle malformation, but without external ear abnormalities, who were operated on at our clinic in the 10 years between June 1993 and June 2002, we studied the condition of ossicles, preoperative examination, surgical procedures, and postoperative hearing improvement. Our study did not include patients with cholesteatoma or those with only fixed stapes but without ossicular deformity. Samples were 12 ears of 11 men and 17 ears of 13 women. We clinically distinguished 3 major categories: (i) discontinuity between the incus and stapes with mobile stapes, (ii) congenital fixation of the stapes with ossicular deformity, and (iii) congenital fixation of the malleus and deformity of the incus with mobile stapes. We classified each category into minor abnormalities based on the condition of the long process of the incus, the superstructure of the stapes, and the stapes footplate. We conducted auditory ossicle reconstruction by mobilization of the malleus and incus in 2 ears, by type III tympanoplasty in 5 ears, by type IV tympanoplasty in 13 ears, and by stapes surgery in 8 ears. Improvement in hearing after the operation was observed in 25 of the 29 ears treated. In the classification of the auditory ossicle malformation without external ear abnormalities, we should evaluate discontinuity or fixation of the ossicles and their deformity. This requires that varied ossicular reconstruction be prepared for surgery, but the possibility of hearing improvement is high, so intensive treatment is needed in many cases of auditory ossicle malformation.