Bone mineral content in osteogenesis imperfecta tarda and in otosclerosis

In 22 patients with osteogenesis imperfecta and in 63 patients with otosclerosis the bone mineral content in peripheral bones was determined by photon absorptiometry. The bone mineral content proved significantly reduced in patients with osteogenesis imperfecta as compared with normals and with patients with otosclerosis. In the latter patients the bone mineral content was normal. These findings support the assumption that stapedial fixation in otosclerosis and in osteogenesis imperfecta is of different aetiology.