In most cases, enlarged aditus, destruction of lateral attic wall, erosion of ossicular chain, exposition of horizontal segment of facial nerve and tegmen of attic were found.

• 12例出现鼓窦扩大、上鼓室外侧壁破坏、听骨链侵蚀、鼓室天盖及面神经水平段暴露等骨质破坏。