Otospongiosis: morphologic and microchemical investigation after NaF-treatment.

Element analysis of microareas of otospongiotic specimens is described. A total of 36 otospongiotic stapes are ultrasectioned without decalcification and examined using a transmission and a scanning electron microscopy (STEM-mode). The latter was equipped with an energy dispersive x-ray analyzer. Twenty of the stapes came from patients who have had sodium fluoride (NaF) treatment (15 to 45 mg/day) for a minimum of 12 months. The otospongiotic stapes are classified as spongiotic and sclerotic according to their pathologic characteristics and state of mineralization. Using the Ca/P ratio as criterion--measured by the characteristic x-ray fluorescence--it was shown in a blind study that the NaF-treated otospongiotic stapes had a statistically higher Ca/P ratio, indicating that the fluoride may stabilize otospongiotic lesions, particularly the spongiotic type with unstable mineralization.