The effect of sample selection on the behaviour of the periodontal index in rheumatoid arthritis.
D000293:Adolescent; D000328:Adult; D001172:Arthritis, Rheumatoid / Q000150:complications; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010510:Periodontal Diseases / Q000150:complications / Q000453:epidemiology; D010512:Periodontal Index; D012494:Sampling Studies; D013223:Statistics as Topic