Comparative Analysis of Dynamic Esthetic Characteristics in Spontaneous Smiles Among Hani and Han Youths in Yunnan Province, China.

Abstract

Objective: The aim of this study is to examine the dynamic esthetic characteristics of spontaneous smiles in Hani and Han youths in Yunnan Province.

Methods: Employing a multistage stratified cluster random sampling approach, participants from the Hani and Han ethnic groups in Yunnan Province were recruited. Digital videography was used to capture facial characteristics at both rest and during spontaneous smiles. Subsequently, selected images were analyzed for dynamic esthetic parameters concerning the lips, teeth, and gingiva using image measurement software.

Results: The study included youths from the Hani (n = 68) and Han (n = 59) ethnic groups in Yunnan Province. During spontaneous smiles, the exposure of maxillary central incisors was more pronounced compared with maxillary lateral incisors and canines in both ethnic groups. Variations in gingival display of central incisors were observed among males in the 2 ethnic groups (P < 0.05). The mobility of the mouth corner's width was significantly greater in Han males compared with Hani males (P < 0.05). Conversely, the width of the mouth corner during spontaneous smiles was greater in Hani females than in Han females (P < 0.05). Regarding the relationship between the gingival line and the upper lip, the unexposed type was predominant among males of both ethnicities, whereas the parallel type was predominant among females. Parallel and straight smile arcs were commonly observed among participants from both ethnicities.

Conclusion: The dynamic esthetic characteristics of the lips, teeth, and gingiva exhibit similarities between the youth of Hani and Han ethnicities in Yunnan Province. However, notable differences in certain dynamic smile esthetic traits exist between the sexes.