Otospongiosis and sodium fluoride. A blind experimental and clinical evaluation of the effect of sodium fluoride treatment in patients with otospongiosis.

The effect of sodium fluoride treatment in patients with otospongiosis has been evaluated blindly in a morphological and microchemical element analysis of otospongiotic specimens together with a prospective clinical double-blind, placebo-controlled study. The results show that using the calcium/phosphorus ratio as an indication for bone maturity, the sodium fluoride treatment can stabilize otospongiotic lesions in retaining calcium relative to phosphorus. The clinical double-blind, placebo-controlled study of 95 patients showed a statistically significant worse deterioration of the hearing loss in the placebo group than in the active treated (40 mg sodium fluoride daily) group, supporting the view that sodium fluoride can change otospongiotic, active lesions to more dense, inactive otosclerotic lesions. We have postulated in the past that the actual mechanism of the cochlear loss is toxic enzymes produced by histiocytes at the periphery of the microfoci, and it may be that sodium fluoride has some effect on these enzymes.