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What is All of the following steps are done in radical mastoidectomy except - and explain in detail?
Steps in radical mastoidectomy

The posterior meatal wall is removed and the entire area of the middle ear, attic, antrum and mastoid is converted into a single cavity, by removing the bridge and lowering the facial ridge.
All remnants of tympanic membrane, ossicles (except the stapes footplate) and mucoperiosteal lining are removed.
The eustachian tube is obliterated by a piece of muscle or cartilage.
The diseased middle ear and mastoid are permanently exteriorised for inspection and cleaning.