[Epidemiological survey on periodontal diseases in Tianjin City and surrounding counties].
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002681:China; D003728:Dental Calculus / Q000453:epidemiology; D003773:Dental Plaque / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009790:Occupations; D010510:Periodontal Diseases / Q000453:epidemiology*; D012737:Sex Factors