title: A study of the effect of age and season on the incidence of ulcerative gingivitis.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D003139:Common Cold / Q000150:complications; D003604:Czechoslovakia; D005260:Female; D005892:Gingivitis, Necrotizing Ulcerative / Q000453:epidemiology*; D006801:Humans; D008297:Male; D012621:Seasons; D012737:Sex Factors