The Primary Research Of Smile Arc And Face Width Influencing Smile Aesthetics In Female

Objective:Smile aesthetics became the focus of orthodontics recently.The smile aesthetics indicator was one of the important factors in a successful orthodontic treatment.Smile arc,buccal corridor,position of smile line,consistency between maxillary midline and face midline,and consistency between maxillary midline and mandible midline were the important indexes of smile aesthetics. The scholars had researched smile arc and it’s impact factors adequately.Most of the studies proved the ideal smile arc gained the highest score in judging smile aesthetics,and others believed there was no relation between the smile arc and smile aesthetics.There were too limited studies in the mouth region, or less sufficient studies in the face type influencing on smile aesthetics. We were trying to find how the smile arc and face width affecting on smile aesthetics in female, as while as the different perceptions in different knowledge bcakground and different sex groups.We hoped our study could offer the evidence to orthodontic treatment for an attractive smile.Methods:We choose a sample of standard female,and her denture was integrated,and there wasn’t any torsional tooth in anterior region. We used the Adobe Photoshop CS5 modifying with the smile arc and face width.The smile arcs were created 3 types: flat,ideal and vaulted;At the same time, the face widths were created 5 types; narrow, relative narrow,ideal,relative wide and wide. The 15 images were divided into 3 groups according to the types of smile arc, and each group included 5 images from narrow to wide face width.The images were taken into the questionnaire and evaluated by the orthodontists and the laypersons for the smile attractiveness with visual analogue scale.Results:1. The smile arc and the face width could influence the evaluation on smile aesthetics (p<0.05).2. The ideal smile arc gained the highest score among the 3 kinds of smile arcs,and there were no statistically significant differences on smile aesthetics between the relative face width and ideal face width for the laypersons and the orthodontists (p<0.05).The relative narrow face width gained the highest score for the layperson,and ideal face width did for the orthodontists.3. For the laypersons, excepting the narrow face width,the smile attractiveness degrees decreased as the face width becoming wider among the 3 kinds of smile arcs(p<0.05), and for the orthodontists,the smile attractiveness degrees depend on different face widths for the 3 smile arcs (p<0.05).4. For the male orthodontists,there were no statistically significant difference among the relative narrow face width,the ideal face width and the relative wide face width (p>0.05),and the score of the relative narrow face width was higher than the other two. The female orthodontists believed there were no statistically significant differences on smile aesthetics among the 5 face widths (p> 0.05), and the score of the ideal face width was higher than the others.5.The smile arc could not influence the evaluation on smile aesthetics when the female or the male laypersons were asked judging with it alone(p>0.05).The ideal face width gained the highest score in male laypersons(p<0.05),and the the relative narrow face width did in female laypersons (p<0.05).Conclusions:The smile arc and the face width could be the factors that influencing the evaluation of smile attractiveness. There were different perceptions about impact of smile arc and face width on smile attractiveness in different knowledge background and sex groups. Therefore,the orthodontist should adjust the positions of the brackets according to the patient’s face width,and form a smile arc suited the patient’s face width in the orthodontic treatment,then we should make an attractive smile suited individual patient.