Esthetic Evaluation Of The Lay Persons To The Smile Line In Women With Different Age

Background With the improvement of aesthetic requirements, more and morepatients seek treatment for a natural charming smile. Orthodontists should concernabout not only the arrangement and occlusion of the teeth, but also the relationshipbetween lips and teeth. In the mean time, orthodontists should pay attention to notonly the shape of the stationary side of the appearance, but also the overall dynamicbeauty of the appearance, creating a charming smile.Revealing a lot of gums whensmile, namely “gummy smile”, will influence the aesthetics of a smile. Gummy smilehas become a hot topic of research in recent years. There are specific therapies fordifferent pathogenesis of gummy smile and can achieve the initial therapeuticpurposes. But no uniform standard for a beauty smile is established at home andabroad. Aesthetic is a subjective, but it is also to comply with certain rules. It hasbeen confirmed that there are different opinions of the aesthetics of the smile lines inorthodontists and the general population. Listening to the views of patients whentreating the gummy smile is necessary; People hold the different ideas in evaluationsof male gummy smile and female gummy smile.So sex is one of the indispensablefactors to be considered when treating patients with gummy smile; Also, there aredifferent views about the gummy smile in different nations and different nationalities.In addition, the amount of exposed gums when smiling will gradually reduce with age.Revealing a few of gums when smiling is considered a younger appearance. But thereare no studies on the evaluation of smile line with different ages at home and abroad.Meanwhile, the clinical orthodontic cases can be divided into adolescent cases andadult cases. The issue that gummy smile treatment is to meet the same standards forboth cases or to consider the patient’s age is worth studying. In order for the clinicaltreatment of gummy smile reference, the aim of this study was to evaluate theinfluence of the smile line on the smile esthetic in women with different age by laypersons. Objective To evaluate the influence of the smile line on the smile esthetic in womenwith different age by lay persons, using a visual analog scale questionnaire．Methods A young woman with beautiful face and coordinate smile was select.Frontal photograph at a standard posed smile were obtained. Photoshop software isused to intercept the picture of the lower face. Two orthodontists, three prosthetists,two oral physicians and one periodontal doctor have confirmed that the age of thefemale in the picture could not be visually distinguished. So the age of the female inthe picture can be considered indistinguishable. Moreover, the model’s intraoralphotograph is obtained. A series of images with different gingival display at smilewere obtained by photoshop software. The images, which were divided into3groups:15years old female images group,25years old female images group and35years oldfemale images group, were rated for attractiveness by lay evaluators using visualanalog scale (VAS). SPSS13.0software is used for statistical analysis.Results1.The age of the evaluators of the25-year-old group larger than the age ofthe evaluators of the25-year-old group, the difference was statistically significant (P<0.01). But the linear analysis show that there is no linear relationship between ageand the evaluators score.2. No significant difference was found when judging theattractiveness of the smile line between the male and the female raters (P>0.05).3.In the smiles without gums exposing, the scores of smile lines between three groupswere not statistically significant expect the scores of SL=-4（P>0.05）. In the smileswith gums exposing, the scores of smile lines between three groups were statisticallysignificant.The scores of each smile line in the15year-old female group were higherthan that in the15year-old female group. Only in the SL=1and SL=2, the scores ofsmile line in the15year-old female group were higher than that in the25year-oldfemale group.4. The scores of15year-old female group is significantly higher thanthat of the other two groups both in the images of gingival exposure（more than0mm） and the images of gummy smile (more than2mm). The scores of25year-oldfemale group is significantly higher than that of the35year-old female group in theimages of gummy smile, but not in the images of gingival exposure.4. In15year-old female group, the highest score picture is the picture of the smile line height of0mm. Smile with smile line height of-3mm to2mm is rated as attractive. In25year-old female group, the highest score picture is also the picture of the smile lineheight of0mm. Smile with smile line height of-3mm to1mm is rated asattractiveness. In35year-old female group, the highest score picture is the picture ofthe smile line height of-1mm. Smile with smile line height of-4mm to1mm is ratedas attractive.Conclusion1. The age of the lay persons does not affect the evaluation of estheticof the smile line.2. There is no difference between men and women evaluators inevaluating the esthetic of the smile line.3. Lay persons were more tolerant thegummy smile in younger female.4. To the15-year-old female group and the25-year-old female group, the lay persons consider that exposing all the upper incisorcrowns without gums when smiling is the ideal smile, while to the35-year-old femalegroup, upper lip covering1mm of the upper incisor crowns is considered to be theideal smile. The attractive smiles of the three groups are sequentially smiles withsmile line height of-3mm to2mm,-3mm to1mm and-4mm to1mm.