Most common site for the initiation of otosclerosis is
In stapedial otosclerosis which is the most common variety, the lesion stas just in front of the oval window in an area called "fissula ante fenestram". Ref: Diseases of EAR, NOSE, THROAT by PL Dhingra; 7th Edition; page no.95
Food plate of stapes
Margins of stapes
Fissula ante fenestrum
Fissula post fenestrum
Ear