Otosclerosis

Otosclerosis (oto, “of the ear,” and sclerosis, “abnormal hardening of body tissue”), also known as otospongiosis, is an abnormal bone remodeling in the middle ear. The normal dense endochondral layer of the bony otic capsule in the labyrinth is replaced by irregularly laid spongy bone leading to the fixation of the stapes. Otosclerosis commonly causes conductive deafness presenting with a normal tympanic membrane. Furthermore, depending upon the foci of involvement on the bony labyrinth, otosclerosis can be asymptomatic or can present as a neurosensory loss. Nevertheless, otosclerosis has an effect on the functioning of the middle and the inner ear.