THE EVANSTON DENTAL CARIES STUDY

XIX. PREVALENCE OF MALOCCLUSION OF CHILDREN IN A FLUORIDATED AND CONTROL AREA

¹ University of Chicago, Chicago, Ill.

The prevalence of malocclusion among children, 6 to 8 and 12 to 14 years of age, is reported. The examinations were separated into pre-fluoride, fluoride, and fluoride-free control groups. The prevalence of malocclusion occurring among the 6- to 8-year-olds after 8 years of fluoridation was 20.48 per cent lower than the pre-fluoride base line group of 6- to 8-year-old children. The 12- to 14-year-old group, after 10 years of fluoridation, showed a decrease of 17.03 per cent when compared with the pre-fluoride base line group of the same age. The prevalence of malocclusion in the fluoride area in 1955 and 1957 was nearly the same as that found in the 1956 control area examinations. In contrast, however, to the reduced prevalence of malocclusion in the study area group, the control area group showed an increase of 11.76 per cent for the 6- to 8-year-old children and 7.84 per cent for the 12- to 14-year-olds over a 9-year period between examinations.

Of 141 children, 6 to 8 years old, with premature loss of the second deciduous molar tooth, approximately one-half, or 54.23 per cent, had normal occlusion. An examination of 84 children at 6, 7, and 8 years of age with the loss of the second deciduous molar prior to 6, 7, or 8 years of age, revealed 50 cases, or 59.52 per cent, of the group to have normal occlusion. Six years later, 40 cases, or 47.61 per cent, of these same children at 12, 13, and 14 years of age had normal occlusion. These children had neither orthodontic treatment nor the advantage of space maintainers.

No increase was found in the percentage of children having orthodontic treatment for the pre-fluoride and fluoride groups. This percentage showed a slight increase for the control area group in 1956 over the 1947 control area group.

From our observations of the data available in our study at the present time, we feel that no definitive statement can be made regarding fluoridation and its effect on the prevalence of malocclusion.