Parent-child similarities in dental caries rates.

Since parents and their school-aged children constitute genetically related individuals living together, parent-child decayed, missing, and filled teeth (DMFT) comparisons offer opportunities to examine the familial influence on dental caries. Appropriate designs allow exploration of the possible influence of sex, apart from sexlinkage, and comparison of caries rates in children of parental extremes. Understandably, such studies demand very large sample sizes, comparisons at narrow age intervals, and (ideally) different racial groupings. To accomplish this, we made use of permanent tooth DMFT data on 6,580 parent-child pairs (4,075 white and 2,505 black) from the TenState Nutrition Survey of 1967-1970 (Department of Health, Education, and Welfare Publication No. HSM 72-8131), comparing age-corrected DMFT of the parents with those of their offspring, arranged by one-year intervals from ages 6 through 18. Since preliminary correlations were comparable for boys and girls, final (pooled) correlations were based on the sex of the parent alone (mother-child, father-child) and the age of the child (midpoint ages 6 through 18) . As given in the table, 52 parent-child correlations for the DMFT were both positive and sta:is:ically significant overall, being systematically higher for 26 mother-child than for 26 father-child age pairs, a trend significant at any useful level of confidence. Similarly, parent-child