Abstract: Objective    To assess the effect of the changes in several smile index on the perceived smile esthetics and evaluate the preferences of smile index in a Han Chinese population，in order to provide reference for clinical diagnosis and treatment. Methods    A frontal image of smile of a volunteer with esthetic facial features was selected and was input into a photo-editing software program and modified by adjusting the following smile characteristics：the buccal corridor ratios，the width ratios between lateral and central incisors，the width-to-length ratios of maxillary central incisor，and the gingival displayed. Finally，24 images with different smile charactistics were obtained. The images were then evaluated by using a visual analogue scale（VAS）by the patients who visited the Hospital of Stomatology，Fujian Medical University ［75 males，83 females，aged（29.8 ± 5.5）years］. Statistical analysis was performed by using Kruskal-Wallis test and Mann-Whitney test. Results    Relatively higher VAS scores were found in the following indexes：a range of 0 to 15% in the buccal corridor ratio，a range of 62% to 87% in the width ratios between lateral and central incisors，a range of 80% to 95% in the width-to-length ratios of maxillary anterior teeth，and a range of -1 to 1 mm in the gingival displayed （all P < 0.05）. Conclusion    The buccal corridor ratios，the width ratios between lateral and central incisors，the width-to-length ratios of maxillary anterior teeth，and the gingival displayed have significant effects on the smile esthetics.

Key words: smile esthetics, Fujian, Han Chinese, preference

摘要： 目的    探讨微笑美学参数的改变对微笑美的影响，并研究福建地区汉族人群对微笑美学参数的喜好度，为临床诊疗提供参考。方法　选取1张美观协调的志愿者（福建医科大学口腔医学院本科生）微笑图像作为模板图像，通过调整颊隙率、侧切牙与中切牙宽度比值、上中切牙宽长比例和牙龈暴露量等微笑美学参数对模板图像进行修改，获得24张微笑图像，作为调查资料。选择2019年3—9月于福建医科大学附属口腔医院就诊的成年患者158例［男75例、女83例，年龄（29.8 ± 5.5）岁］作为调查对象，对24张微笑图像进行视觉模拟评分（visual analogue scale，VAS），并对所获VAS评分进行Kruskal-Wallis检验和Mann-Whitney检验。结果　颊隙率为0 ~ 15%、侧切牙与中切牙宽度比值为62% ~ 87%、上中切牙宽长比例为80% ~ 95%，以及牙龈暴露量为-1 ~ 1 mm时，其VAS评分在相应微笑美学参数中相对较高（均P < 0.05）。结论    颊隙率、侧切牙与中切牙宽度比值、上中切牙宽长比例以及牙龈暴露量均可对微笑美产生显著影响。

关键词: 微笑美学, 福建, 汉族, 喜好度