A study on craniofacial morphology of Japanese subjects with normal occlusion and esthetic profile.

This study was designed to properly characterize the cephalometric values of Japanese individuals with both normal occlusion and esthetic profiles. Multivariate statistics were applied to analyze the collected data. Cephalometric values identified are expected to help in the simplification of orthodontic diagnosis. Lateral cephalometric radiographs from 50 men and 50 women with normal occlusion were traced and the dimensions of hard and soft tissues recorded. The corresponding values were classified by cluster analysis, and selected representative values were subjected to principal component analysis. From these values, characteristics of hard and soft tissue morphology were extracted. The subjects were grouped by sex, and subdivided into esthetic and unesthetic profile groups. The principal component scores from each group were plotted on a scattergram and the characteristics of each group investigated. The hard tissue characteristics in men with esthetic profiles were primarily vertical factors, including a tendency for smaller lower facial heights, a smaller mandibular plane angle, and a larger Nasion-ANS/ANS-Menton (N-ANS/ANS-Me). Soft tissue features included a more posteriorly placed maxilla and a high nasal crest. These features yield a less marked maxillary prognathism and a greater nose prominence. In females, hard tissue characteristics associated with esthetic profiles primarily involved the cranial base and posterior facial area. These included a smaller saddle angle, larger articulare angle, and smaller Sella-Articulare/Articlare-Gonion (S-Ar/Ar-Go). Female soft tissue characteristics primarily included retracted upper and lower lips, a shallow inferior sulcus with a smaller lower lip-Frankfort plane angle, and a shorter mentolabial sulcus and subnasale perpendicular-upper lip.