The dimensions of the maxillary and mandibular dental arches were measured from 280 subjects aged between 3 and 15 years in a cross-sectional study. The growth changes were examined by means of canonical analysis, a multivariate technique. This technique enabled the dental arches to be treated as biological units, rather than a series of discrete parameters, as is possible using univariate techniques. The results showed that the size and shape of the dental arches changed maximally between the periods 5–7 and 11–13 years of age. These periods correspond to the major phases of permanent tooth eruption.