Crown size variability in the deciduous dentition of South Australian children.

Although many studies of the permanent dentition have been published, there are still relatively few reports relating to variability within the deciduous dentition. The aim of this study was to provide a detailed description of crown size variability in the deciduous dentition of South Australian children. Dental impressions were obtained of 160 children, 3-6 years of age, and stone models constructed. Mesiodistal and buccolingual crown diameters were recorded from the dental models using a computerized data acquisition system. Several aspects of deciduous tooth size were studied, including variation within and between dental arches, sexual dimorphism, and correlations within and between crown diameters. Principal components analysis was used to summarize the inter-correlated tooth size data and to facilitate the biological interpretation of common variability. The magnitude and pattern of mean values for deciduous tooth size were similar in South Australian children to published data for other Caucasian populations. Although mean values for tooth size were generally larger in boys than in girls, sexual dimorphism in deciduous tooth size was low. Correlation analyses indicated low to moderate associations for size between teeth in the same arch, with highest values between the molars. In both sexes there was a tendency for correlations between buccolingual dimensions to exceed those between mesiodistal dimensions. Although distinct morphogenetic fields have not been defined in the deciduous dentition, there appeared to be a gradient of decreasing size variability from anterior to posterior, with the second deciduous molar being particularly stable. The observed pattern of phenotypic variation appeared to be directly related to the relative length of the developmental period that tooth crowns spent in the soft tissue stage prior to calcification. Multivariate analyses confirmed some overall coordination for crown size of deciduous teeth, but also highlighted specific size patterning related to incisor, canine, and molar regions. © 1993 Wiley-Liss, Inc.