WHO Basic Methods Research Articles

CPITN, DMFT, and treatment requirements in a Nicaraguan population.

WHO basic methods were used to assess CPITN, DMFT, and treatment requirements in a population of 178 persons aged 12-64 yr living in urban and rural areas of Nicaragua. Two groups were examined: individuals presenting for dental treatment at health clinics (30%) and subjects chosen randomly at other locations (70%). Mean ages of both groups were similar although females were found in higher percentages among those presenting for dental care. With the exception of one young individual, all subjects had calculus in at least one sextant. About 26% of the subjects who presented for treatment had a > or = 6 millimeter pocket compared to about 14% of the remainder of subjects. The mean DMFT for health clinic subjects was 16.1 compared to 10.3 for subjects from other locations. Subjects presenting for treatment had twice as many missing teeth and a mean of 0.5 filled teeth compared to 2.4 filled teeth for other subjects. Subjects at the clinics were in greater need of restorative care and extractions, while subjects from other locations were found to have more teeth that did not require any treatment. Health clinic subjects reported more visits to the dentist in the last year than other subjects. Only 80% of those presenting for treatment owned a toothbrush compared to 97% of those examined in other locations, and the latter group reported brushing their teeth more frequently. Attrition was a commonly encountered tooth disorder with 53% of all subjects exhibiting this condition.

Standardization of the Epidemiologic Assessment of Periodontal Diseases: Surveys in the South Pacific

Attempts of introducing uniform techniques for the collection of statistical data on the prevalence of periodontal diseases have been made by FDI and WHO in order to arrive at valid, reproducible, and internationally comparable results. The WHO Manual of the International Classification of Diseases. Application to Dentistry offers a five digit classification of all oral diseases for statistical purposes. In contrast to morbidity statistics, epidemiological surveys must be based on adequate samples, representative for the entire population or distinct strata thereof. FDI is actually preparing guidelines for the conduct of clinical trials in periodontal diseases, comparable to those on caries incidence, indicating the proper use of indices. For the epidemiological assessment of periodontal diseases, the WHO Basic Methods (1962, 1971) have recommended the use of simple ratios of persons affected with signs of the disease. Data collected in four extensive dental surveys in Polynesian and Melanesian populations in the South Pacific served as an example to show the variety of valid information provided by these basic methods. The main results showed an early appearance of pocket formation at ages 10 to 14, preceded in a statistically significant way by calculus formation and gingivitis. A constant pattern in the sequence of attack of the various teeth by pocket formation was shown to be specific for these island populations; males were consistently more affected than females. The character of periodontal diseases prevalent among Polynesians and Melanesians was recognized to be a "dirt pyorrhea" accompanied by progressive subgingival calculus deposition and destructive periodontitis.