Identification of High Caries Risk Group and Prediction for Permanent Teeth Caries in Schoolchildren

Abstract

The supplies of two elementary schools', one in Tokyo (School N) and the other in Saitama (School F) were investigated to predict the caries incidence in the 6th grade from the data of 1st graders and to identify the children at high risk for caries. The results were as follows. 1. The two schools showed almost no gender difference. In comparison between the two schools, all 14 indices except ft of the molar region at the age of 6(6-M-ft), the ft of the front region at the age of 6(6-F-ft), FT at the age of 6(6-FT), DT at the age of 11(11-DT) and &lrtri;DMFT from 6 to 11 years of age (6-11&lrtri;DMFT) had significant difference at p<0.01. 2. The ROC curve of 11-DMFT, in which fewer than 3 DMFT was fixed as negative, had the least estimative probability of all three curves. 3. The estimative probability of school N was higher than that of school F. 4. To predict caries in the 6th grade, more than 5 dmft at 6-M-dmft was judged as a high risk when the cut-off point was set at 4. The same result was seen at 6-dft. 5. To evaluate the increase of caries in permanent teeth in the 6th grade, more than 5 dmft at both 6-M-dmft and 6-dft was judged as a high risk when the cut-off point was set at 4. 6. To predict the children who would have more than 4 DMFT at 11-DMFT, more than 6 dmft at both 6-M-dmft and 6-dft was judged as a high risk when the cut-off point was set at 5. 7. When 11-DMFT was set as an objective value, a significant multiple regression equation : 11-DMFT = 0.37(6-M-dt) + 0.30(6-M-ft) + 0.65(6-M-mt) + 0.59(6-M-mt)+0.30(6-FT), 1.04 was obtained at P <0.01. 8. When 6-11 &lrtri;DMFT was set as an objective value, a significant multiple regression equation : 6-11-DMFT = 0.34(6-M-dt) + 0.29(6-M-ft) + 0.59(6-M-mt) + 0.30(6-FT) + 1.03 was obtained at P<0.01. Therefore, the prediction of the number and increase of caries in the 6th grade can be detected from children in the 1st grade. This should be applied in actual dental health care of schools.