Table 3: This table displays the middle ear risk (MER) index and the ossiculoplasty outcome parameter staging (OOPS) index. For each risk factor, corresponding scores were allotted that were summed up. For the MER index, the categories from 0–3 (light), 4–6 (moderate), and 7–12 (severe) disease were applied. The higher the total score was in the according index, the more difficult is it to determine the disease and the poorer is the prognosis for the reduction of the postoperative air-bone gap (M: malleus; I: incus:, S: stapes; +: present; –: missing).