Integration of parts in the facial skeleton and cervical vertebrae.

Introduction: The purpose of this study was to undertake an exploratory analysis of the relationship among parts in the facial skeleton and cervical vertebrae and their integration as 2-dimensional shapes by determining their individual variations and covariations. The study was motivated by considerations applicable to clinical orthodontics and maxillofacial surgery, in which such relationships bear directly on pretreatment analysis and assessment of posttreatment outcome.

Methods: Lateral radiographs of 61 adolescents of both sexes without major malocclusions were digitized and marked up by using continuous outline spline curves for 8 defined parts in the facial skeleton, including the cervical vertebrae.

Pitch, roll, and yaw: describing the spatial orientation of dentofacial traits.

The value of systematically enhancing the Angle classification by including transverse and vertical characteristics in addition to anteroposterior relationships for the face and the dentition is universally accepted. Three aeronautical rotational descriptors (pitch, roll, and yaw) are used here to supplement the planar terms (anteroposterior, transverse, and vertical) in describing the orientation of the line of occlusion and the esthetic line of the dentition. Each of the latter traits affects the modern clinical practice of orthodontics because of its greater focus on dentofacial traits beyond the correction of malocclusion.