Objective: To investigate and analyze the characteristic of destructive ossicular chain and it's impact on air-bone gap (ABG) among patients with cholesteatoma.
Method: Data from 204 cases (213 ears) undergoing an initial surgery for cholesteatoma were retrospectively reviewed to evaluate the relationships between preoperative pure tone audiometry data and intraoperative assessment of individual ossicular destruction.
Result: Incus was the most significantly affected ossicle. Furthermore, the destruction of malleus and stapes was often accompanied by the destruction of incus. A partially eroded incus caused significantly increase in ABG from that of an intact incus with cholesteatoma abutting (P < 0.05). A partially eroded incus and a partially eroded stapes caused significantly increase in ABG compared to a partially eroded incus (P < 0.05). A completely eroded incus caused significantly increase in ABG compared to a partially eroded incus (P < 0.05). False fibre-connected would significantly influence on ABG in some ossicular chain erosion patterns (P < 0.05). Cholesteatoma abutting an intact ossicle significantly altered average ABG compared to a normal ossicle (P < 0 01).
Conclusion: Different ossicular chain erosion pattern caused different degrees of ABG.