A family study of craniofacial dimensions in the Burlington Growth Centre sample

Abstract

Lateral cephalometric radiographs were used to study the similarities in craniofacial dimensions between members of 147 families. Standard product-moment and intraclass correlation coefficients were calculated for a selected series of measurements to compare parents to offspring and sibs to sibs. To assess further the use of the parents' records in predicting a child's craniofacial features, r2 values were calculated and multiple regression analyses were performed for the various pairings of related individuals. Results show a high level of significant correlations between first-degree relatives which are compatible with a polygenic theory of inheritance. These data give no evidence of added effects of autosomal dominance and sex-linkage. As might be expected, the use of multiple measurements from both parents gives the best results when one is attempting to predict a child's craniofacial dimensions. This suggests that information from the parents and siblings of a patient can be quite useful in clinical orthodontic treatment.