This study, utilizing histologic evaluation of foot-plates removed before and after sodium fluoride administration and substantiated by strontium 85 studies, indicates that sodium fluoride is active in reducing the osteoblastic activity in the otosclerotic focus and in half of the cases changes it from an otospongiotic to an otosclerotic lesion.
This is particularly important as regards cochlear otosclerosis, as evidence now indicates that otosclerosis can produce both a conductive and a sensorineural hearing impairment. Administration of sodium fluoride should prevent progression of the sensorineural component of cochlear otosclerosis. The relatively high incidence of cochlear otosclerosis as a cause of progressive, hereditary sensorineural hearing loss has only recently been recognized.