Progressive and regressive changes in Hungarian oral leukoplakias in the course of longitudinal studies.

Follow-up studies of 520 patients with leukoplakia during a 25-year period showed changes in the clinical type in 66 cases, i.e. 12.7%. Regressive changes occurred in 9%, progressive changes in 3.7%. The highest frequency of change in the clinical type was found in the group of erosive leukoplakias. The most frequent changing sites were the labial mucosa, commissures and buccal mucosa. Of the etiologic factors, smoking and Candida infection seemed to be correlated with the change of type. Oral leukoplakia should be considered a dynamic changing lesion of the oral mucosa.