[Survey on nutrition of infants in the Tokyo metropolitan area. 1. Carious dentitions, anomalies of occlusion and ways of eating].

In September, 1987, a survey on the nutrition of infants was conducted with 1,235 children from 3 to 6 years of age selected from six nurseries and six kindergartens in the metropolis of Tokyo. We compared the survey results with other similar survey reports with respect to three areas; 1, caries attack on primary teeth, 2, anomalies of dentition and occlusion and 3, how foods are eaten, to observe the difference by age and also between children in nurseries and in kindergartens. The following are the results of this comparative investigation. 1) The ratio of caries attacks on the 4-year-old in this survey was 69.6%, which was lower than the 83.4% of the nationwide survey of 1987 conducted by the Ministry of Health and Welfare, while the average value of the df index per person was 4.7, which was lower than the 6.1 of 1981. 2) The caries incidence rate was higher with children in kindergarten than those in nurseries and many kindergarten children had had more than one caries attack. 3) The frequency rate of anomalies of dentition and occlusion in the entire survey sample was 12.9% for deep overbite, 11.4% for open bite and 10.7% for edge-to-edge bite. 4) In the survey of how foods were eaten, the question, "Does your child like to eat things that are hard to bite on?" was asked, and 10.4% of the group answered "My child prefers eating soft food," which was quite high. To the question, "Does your child often eat things that are difficult to eat?", 17.1% of the entire group answered, "My child refuses to." This tendency was greater among the children in kindergaretens.