Consequences of middle ear bone dust during neurotologic surgery.

Most otologists are cautioned at some point in their training that if bone dust is allowed to enter the middle ear while the mastoid is being drilled, there may be adverse consequences. Two cases of ossicular fixation and conductive hearing loss after retrolabyrinthine vestibular nerve section prompted us to examine the issue of bone dust in the middle ear. In a study of 13 temporal bones that had undergone neurotologic surgery, we found 11 that showed evidence of viable bone dust in the middle ear, and three that had ossicular fixation. Viable bone dust was always encased in a mucous membrane lining. These findings suggest that bone dust that enters the middle ear may indeed remain viable and cause ossicular fixation. The surgeon should therefore take every precaution to prevent bone dust from entering the middle ear during neurotologic procedures in which conservation of hearing is attempted.