THE INFLUENCE OF FLUORIDATION OF DRINKING-WATER ON THE LONG-TERM HEARING RESULTS OF STAPEDECTOMY

The long-term hearing results of stapedectomy were assessed in 294 pat ients with otosclerosis living in an area where the natural waters hav e a very low fluoride content. Only patients with an initially success ful outcome were included. Patients having an additional known cause o f hearing loss were excluded. The mean follow-up period was 9 yr. From the best hearing levels achieved 6 to 12 months after surgery, the me an air conduction thresholds showed an annual impairment of 0.4 to 1.1 dB/year and bone conduction thresholds an annual impairment of 0.5 to 1.0 dB/year. There was no significant difference between patients dri nking fluoridated tap water and those drinking low-fluoride water. It is concluded that a daily sodium fluoride intake of 1 to 3 mg in a low -fluoride area is too small to have a significant effect on hearing im pairment after stapedectomy.