The Third National Health and Nutrition Examination Survey(NHANES III) is part of a continuing series of studies conducted to assess the health status of Americans. The NHANES III was conducted in two phases. Phase I collected data from 1988-1991 and phase two collected data from 1991-1994. Phase II data are not yet available. Today I would like to discuss what we have learned from the results of the oral health component of phase I.
According to the Journal of the American Dental Association, The data obtained served two primary purposes.
- To develop estimates of the prevalence and distribution of oral disease and conditions among the populace during this period of data collections.
- To discern trends in the oral health of Americans by comparing
NHANES III survey findings with previous surveys.
The survey found that in children under ten years of age more than 60 percent had a caries (decay) free primary dentition (baby teeth).
Among children and adolescents age 5 to 17 about 55 percent were caries free in their permanent dentition. However, fewer adolescents age 12 to 17 were caries free (32.7 percent) then children age 5 to 11 (74.0 percent).
The percentage of caries-free children in the 5 - 17 year age group is even more significant when you compare to previous survey results. Only 26 percent of children age 6 - 17 were reported to be caries free in their permanent dentition in the 1971 - 1974 national survey.
Subsequent national surveys reported that the percentage of caries free children age 5 - 17 increased to 36.6 percent in 1979-80, 49.9 percent in 1986-87 and 54.5 percent in 1988-1991. In other words, in less than two decades, the percentage of children without decayed permanent teeth has doubled.
In studying the significance of dental sealants, the percentage of children having sealants more than doubled since the last national survey was conducted. However, a disappointing one in five children are receiving this safe and effective preventive measure.
A disturbing trend was picked up by the survey. Most decay occurs in the permanent teeth of a relatively small number of children. Twenty five percent of the children age 5-17 account for about 80% of the total decay.
The survey also showed that the occlusal or the chewing surface of teeth -which is where sealants are placed- was the most common involved surface for decay whether they were looking at age, gender or race-ethnicity groupings. In other words, if more teeth were sealed we would find a further reduction in tooth decay.