Experimental Otosclerosis: Its Causation by Ionizing Radiations

Abstract

Foci of osteogenesis of otosclerotic appearance were obtained in the enchondral layer of the otic capsule of dogs, using ionizing radiations. In the first dog 5 sessions were carried out over 17 days. The total dose given was 8330 rads and 7920 rads in the right and left ear, respectively. The second dog underwent 6 sessions over 22 days and received a total dose of 7920 rads and 5280 rads in the right and left ear, respectively. The petromastoid portions of the temporals were fixed in 10% formaldehyde and decalcified in 5% aqueous solution of trichloroacetic acid. The following histologic techniques were performed: H & E, Wilder, PAS and Scarlach red. In the enchondral layer of the otic capsules of the first dog 3 “otosclerotic” foci were found in the walls of the internal auditory duct and of the cochlea. In the second dog, a diffuse osteogenic reaction was observed. It is believed that the osteo-genic foci obtained fulfil the requirements set out by various authors as demonstrative of experimental otosclerotic lesions. It is furthermore contended that such foci are repair areas in a devitalized enchondral layer with extensive zones of necrosis.