ABSTRACT
Otosclerosis (OTSC) is a disorder of the bony labyrinth and stapes known to affect only humans. It affects the bone homeostasis of the labyrinthine capsule, resulting in abnormal resorption and redeposition of bone. This bone dysplasia limited to the otic capsule originates in the endochondral bone layer. OTSC neither affects other endochondral bones in humans nor is found in animals. OTSC is the most important cause of chronic progressive conductive hearing loss in adults and a significant cause of progressive sensorineural hearing loss as well (1). Conductive hearing loss develops when otosclerotic foci invade the stapediovestibular joint (oval window) or round window region and interfere with the free motion of the stapes. Although the sensorineural hearing loss cannot be corrected, stapes microsurgery has proven to be a highly successful means to restore normal ossicular conduction and improve hearing thresholds.
