tegmen
1.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.
2.②Bone changes,including the bone erosion of scutum attic lateral wall,and enlargment of the tympanic cavity with sclerotic border,the dislocation and destruction of the ossicles. The sigmoid sinus plate,tympanic tegmen,semicircular canal and facial nerve canal were destroyed in severe cases.
3.Results Of sixty|eight ears diagnosed as chronic otitis media properatively by HRCT coronal and axial scanning,twenty|eight were cholesteatomas,the typeical appearances were a large softtissue mass in the epitympanic cavity,sinus tympani and aditus,enlargement of the antrum tympanicum and its aditus,destruction of the tympanic tegmen,disappearance of the k?rner′s partition,and sclerotic mastoid appeared in most of them;
