A reconsideration of the parameters for evaluating tympanic reconstruction

Twenty years' experience with tympanoplasty operations incorporating ossicular reconstruction revealed some unexpected improvements in bone conduction thresholds postoperatively. Because there appeared to be a relationship between this occurrence and the degree of air-bone closure, the possibility that bone conduction thresholds were related to the efficiency of the middle ear sound transformer mechanism was investigated. It has been possible to demonstrate that such a relationship does exist. Its extent and the possible underlying mechanisms are discussed. It is concluded that the evaluation of ossiculoplasty results would be more realistic if they were based on a parameter that measures cochlear function with greater accuracy than do preoperative bone conduction thresholds.