A multivariate analysis of the relations between craniofacial structure and occlusion with DiPaolo's quadrilateral measures.

This study examined the relations between craniofacial structure and occlusion with clinically oriented skeletal measures consistent with Enlow's counterpart principle and a combination of univariate and multivariate statistics. The pretreatment lateral cephalograms and dental casts of 59 white adolescents with natural skeletal and occlusal development were selected to provide a random sampling of various malocclusions. Craniofacial structure was described with DiPaolo's quadrilateral measures. The relations between craniofacial structure and occlusion were analyzed with simple correlation analysis, stepwise multiple regression, and stepwise discriminant analysis. Intratester and intertester reliability were established, and a lack of sexual dimorphism was demonstrated. Three types of relations were identified: anteroposterior relations, vertical relations, and coordinations. A strong association was found between the variation in the anteroposterior measures and the variation in sagittal occlusion. A more modest association was found between the variation in the vertical measures and the variation in vertical occlusion. A combined skeletal measure composed of the variable pair mandibular plane angle and the ratio of anterior lower facial height to anterior upper facial height was found to explain the greatest percent of the variance in vertical occlusion. Several coordinations were found which, when taken together, described an overall pattern of associations.