Relationship between cranial base structure and maxillofacial components in children aged 3-5 years.

The aim of this study was to clarify the inter-relationships between cranial base angle, the morphological variations of maxillofacial components, and growth of the anterior cranial base length. One hundred and twenty-two Japanese children aged 3-5 years with normal occlusion in the primary dentition were included in this investigation. To analyse the relationship between cranial base structure and maxillofacial components, the subjects were divided into three groups according to facial type (prognathic, orthognathic, or retrognathic) assessed by the magnitude of their NSAr angle (as cranial base angle). These categorized cephalometric profiles suggested that the antero-posterior location of the maxillofacial components corresponded to the NSAr angle. Factor analysis of cephalometric variables showed that the variation of maxillofacial components from the S-N line was strongly related to the cranial base angle. This normal range of morphological variation was distinguished from that of growth by the factor loadings. From these results, theoretical models of cephalometric profiles with normal occlusion were computed by linear regression analysis. Using the models, a standard profile related to an arbitrary cranial base angle was obtained for children with normal occlusion, aged 3-5 years.