Diseases of The Middle Ear
Cholesteatoma is commonly caused by: [LQ]
|C||Central perforation of tympanic membrane|
Tubotympanic type (safe or benign type)
a. It is associated with central perforation of tympanic membrane and involves the anterior inferior part of middle ear deft (eustachian tube and mesotympanum).
b. There is no association with cholesteatomA.
c. Tubotympanic type is also called safe or benign type as there is-no risk of serious complicatiions.
Attico-antral type (unsafe or dangerous type)
a. It is associated-with an attic or a marginal perforation of the tympanic membrane and involve postero-superior part of middle ear cleft.
b. The attico-antral disease is characterized with cholesteatoma whi.ch erodes the bone.
c. Risk of intracranial extension of infection, and thus the risk of complication, is very high, therefore it is called danqerous or 'unsafe ear.