Determination of craniofacial growth in patients with untreated Class III malocclusions and anterior crossbites using...

The aim of this investigation was to assess average Class III craniofacial growth in Japanese males and females, using cross-sectional data from infancy to adulthood. Growth was analysed using the centroid method. Centroid G was geometrically calculated from the triangle Delta abc, which comprised the palatal, articulare-gnathion (Ar-Gn), and A-B planes. Lateral cephalograms were obtained of 323 Japanese males and 611 females aged 2 years or older but under 25 years of age. Each dataset was divided into 2 year intervals according to age and categorized into 10 developmental stages. One-way analysis of variance followed by a Bonferroni's t-test was used to compare the results for each group of males and females separately. No significant gender differences were observed in the palatal plane to Ar-Gn plane angle. In males, significant increases in the palatal plane to A-B angle were found up to 14-15 years of age and in the area of Delta abc, G-G' and Ms-Ms' values up to 16-17 years. Among females, changes in these cephalometric measurements showed tendencies that were nearly identical to those of males. These findings provide the characteristics of Class III malocclusions in the growth and developmental period, and as they can be used as standards for understanding the effectiveness of Class III treatment, they may be useful in orthodontic and/or orthopaedic diagnosis and treatment planning.