The Influence Of Vertical Discrepancy On Chinese Facial Profile Esthetics

As known, the final goal of orthodontic treatment is to achieve a harmonious dentofacial complex with a good skeletal, dental, and soft tissue balance in function and esthetics. Self-perception of dentofacial attractiveness is an important chief complain for patients to seek orthodontic treatment, which is most evident in adult patients. Greater attention has been paid to three-dimensional facial analysis in recent years, along with the increased patients' esthetic demand and the increased number of adult patients. The aim of this study was to define the influence of vertical discrepancy on Chinese male and female facial profile esthetics and the relative influence on attractiveness of vertical proportion and skeletal anteroposterior relation. And also, this research was designed to compare the inter-group differences in participants' rating. Method: 134 subjects participated this study, but only 126 persons completed, comprising 27 adult patients, 25 adolescents' parents and 26 laypersons, 14 oral surgeons, 34 orthodontists. The digitized lateral cephalometric radiographs of a Chinese man and a woman, each with a normal profile, a Class I molar relationship, and a Class I skeletal pattern, were used as the initial profiles. The profiles were modified to obtain 2 other images of each sex by artificially altering ANB value to 0°and 6°without any change to SNA angle and vertical height. Then 27 profiles of each sex were generated from the images mentioned above with lower vertical proportion increased or decreased by up to 4 standard deviations (SDs) from the Chinese norm. Finally they were manipulated to silhouette profiles and randomly arranged. The participants were asked to score each image using a 9 point numerical scale. The male profiles were rated once again after 2 weeks to assess the rating repeatability. Result: The images with lower anterior face height/total anterior face height (LAFH/TAFH) deviated within 1SD of the norm were rated the most attractive, while the images with LAFH/TAFH reduced by 4SDs from the normal were rated the least attractive. Attractiveness scores reduced as the vertical proportions diverged from the normal value (P＜0.05). However, the scores of the ClassⅢmale images demonstrated little differences while vertical proportion changed and they were generally lower than those of the ClassⅠandⅡ. The ClassⅢskeletal pattern had the most negative influence on the rating scores of male silhouettes, followed by vertical discrepancy. Significant differences were observed between the 5 groups' average rating of the male and female profiles (P＜0.05). Sex or age of the participants was found to have no significant influence on the result.Based on these findings, vertical discrepancy had influence on the facial profile esthetics. Profile attractiveness reduced as the vertical proportions diverged from the normal value. For the ClassⅠandⅡmale profiles, images with reduced lower face proportions were considered to be more attractive than corresponding images with increased lower face proportions, while the opposite trend was found for the ClassⅢmale images and the female. The ClassⅢanteroposterior relation had the most negative influence on the male profile esthetics, followed by vertical discrepancy. But for the female, it was difficult to determine the relative influence of the vertical proportions and the anteroposterior relations in this study. Specialty of the participants was found, to some degree, to have influence on their esthetic standard.