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What is The postero superior retraction pocket, if allowed to progress, will lead to: and explain in detail?
In ventilation of the middle ear cleft, air passes from eustachian tube to mesotympanum, from there to attic, aditus, antrum and mastoid air cell system. Any obstruction in the pathways of ventilation can cause retraction pockets or atelectasis of tympanic membrane, e.g.: Obstruction of eustachian tube degTotal atelectasis of tympanic membrane Obstruction in middle ear ' Retraction pocket in posterior pa of middle ear while anterior pa is ventilated Obstruction of isthmi (r) Attic retraction pocket Depending on the location of pathologic process, other changes such as thin atrophic tympanic membrane, (due to absorption of middle fibrous layer), cholesteatoma, tympanosclerosis. and ossicular necrosis A posterior superior retraction pocket - if allowed to progress leads to primary acquired cholesteatoma and not secondary cholesteatoma.