Quantitative analysis of the morphology of the lips according to different anteroposterior and vertical skeletal patterns

Abstract

Objectives: The aim of this study was to compare the differences in the morphology of the lips according to anteroposte-rior dentoskeletal patterns and facial divergence.Materials and Methods: The samples were composed of the frontal facial photographs of 117 adult patients who satisfied all the cephalometric measurements for six groups (Class I or II or III and normodivergent or hyperdivergent). The morphol-ogy of the lips was evaluated on the frontal facial photographs and the measurements were compared between the groups.Results: In the normodivergent groups, the height-to-width ratio of the lip vermilion was significantly greater in the Class II group than in the Class I group, and the labrale superius angle and upper lip convexity of the Class II group was smaller than that of the Class I group. In the hyperdivergent groups, the stomion inferius angle of the Class III group was smaller than that of the Class II group. Lower facial height and the interlabial gap in the hyperdivergent groups tended to be larger than those in the normodivergent groups. The height-to-width ratio of the lip vermilion and the commissure height were larger in the hyperdivergent groups than in the normodivergent groups. However, the upper lip height and philtrum height did not differ between the hyperdivergent and normodivergent groups.Conclusion: The morphological characteristics of the lip vermilions on the frontal view differed according to the sagittal dentoskeletal relationship and facial divergence.