Abstract
Osteogenesis imperfecta, often called the syndrome of Van der Hoeve-de Kleyn, consists of blue sclerae, fragilitas ossium and hardness of hearing. Previous authors have considered the impairment of hearing to be due to, and identical with, otosclerosis. But in recent years some authors have questioned this opinion. The author presents four cases in which a stapes mobilization was performed in five ears.