<prompt> Most common site involved in Otosclerosis isFoot plate stapesMalleus headIncusEar drum  <response>: A Foot plate stapes Stapedial Otosclerosis: Stapedial otosclerosis causing stapes fixation and conductive deafness is the most common variety. Here lesion starts just in front of the oval window in an area call fissula ante fenestram. This is the site predilection anterior focus. Lesion may be behind the oval window posterior focus, around the margin of the stapes foot plate circumferential, in the foot plate but annular ligament being free biscuit type. Sometimes, may completely obliterate the oval window niche obliterative type. 