The effect of drinking water fluoridation on the natural course of hearing in patients with otosclerosis.

The effect of drinking water fluoridation on the course of hearing of non-operated otosclerotic ears was assessed in an area where the natural waters have a very low fluoride content. The study population consisted of 150 patients with surgically proven otosclerosis. Patients having an additional known cause of hearing loss were excluded from the study. Every patient had a follow-up of at least 5 years, the mean follow-up period being 8.8 years. At last follow-up examination, air conduction thresholds of patients drinking fluoridated tap water were found to be significantly better than those of patients drinking fluoride-poor water, likewise there were significant differences in bone conduction thresholds at 1, 2, and 4 kHz. It was concluded that drinking water fluoridation has a beneficial effect on hearing levels of non-operated otosclerotic ears.