Age changes in dental arch dimensions of Australian Aboriginals

Breadths and depths of the dental arches were measured from standardized photographs of serial casts of Australian Aboriginals enrolled in a longitudinal growth study. The data were obtained from 1161 sets of casts representing 111 boys and 86 girls ranging in age from 6 to 19 years. Age changes in the arch dimensions conformed to previously described patterns in Caucasian children, namely, an increase in breadth and a decrease in depth. Corresponding dimensions and dimensional changes in the maxilla and mandible were strongly correlated, but breadth and depth changes were relatively independent. The disparity in size between arches increased with age, particularly in the breadth dimension of boys. Marked disparity in arch breadths characterizes an occlusal feature of this population that has been termed alternate intercuspation.