The Complications Of Chronic Inflamatuar Middle Ear Pathologies

Chronic otitis media and mastoiditis are the result of infection by an organism of low virulence or of acute infection with incomplete resolution. Mastoid inflammation produces thickening of some trabeculae secondary to reactive new bone formation and at the same time mineralization of other trabeculae. A cholesteatoma is an epidermoid cyst that consists histologicaly of an iner layer of stratified squamous epithelium. The lumen of the cyst is filled with desquamated epithelial debris. As the cyst enlarges and comes into contact with contigious bony structures of the middle ear, mastoid and petrous pyramid, erosion of these structures occurs owing to pressure necrosis and enzymatic lysis of bone. Ossicular erosion is seen %70 ratio. Ossicular erosion is seen later and the long crus of incus is eroded the most frequently. But the bigger lesions may make erosion whole ossicles. Cholesteatomas may make tegmen erosion, mastoid cortex irregularity, fasial nevre contour irregularity and semisircular canal defect according to bigness and period. Tympanosclerosis develops in the result of collecting hyalin and calsific deposits in tympanic membran and the submucosa of middle ear. These are tympanosclerotic plugs. It appears in the result of otitis media or trauma.