What is true in case of perforation of pars flaccida -
Tympanic membrane can be divided in 2 parts:
Parstensa : It forms most of the tympanic membrane. Its periphery is thickened to form fibro cartilaginous ring called as annulus tympanicus.
Pars Falccida : It is situated above the lateral process of malleus between the notch of Rivinus and the anterior and posterior malleolar fold.
Ref. Dhingra 6/e p59, 5/e p 78
CSOM is a rare cause
Associated with cholesteatoma
Usually due to trauma
All of the above