Smile Images Research Articles

Digital detection of Alzheimer’s disease using smiles and conversations with a chatbot

In super-aged societies, dementia has become a critical issue, underscoring the urgent need for tools to assess cognitive status effectively in various sectors, including financial and business settings. Facial and speech features have been tried as cost-effective biomarkers of dementia including Alzheimer’s disease (AD). We aimed to establish an easy, automatic, and extensive screening tool for AD using a chatbot and artificial intelligence. Smile images and visual and auditory data of natural conversations with a chatbot from 99 healthy controls (HCs) and 93 individuals with AD or mild cognitive impairment due to AD (PwA) were analyzed using machine learning. A subset of 8 facial and 21 sound features successfully distinguished PwA from HCs, with a high area under the receiver operating characteristic curve of 0.94 ± 0.05. Another subset of 8 facial and 20 sound features predicted the cognitive test scores, with a mean absolute error as low as 5.78 ± 0.08. These results were superior to those obtained from face or auditory data alone or from conventional image depiction tasks. Thus, by combining spontaneous sound and facial data obtained through conversations with a chatbot, the proposed model can be put to practical use in real-life scenarios.

Role of canine vertical position and gingival zenith level on smile aesthetics and qualitative evaluation of perception by orthodontists, general dentists and laypersons: A descriptive cross-sectional study

: Our objectives were to verify the impact of alterations in the vertical position of the maxillary canines in smile aesthetic perceptions and to determine whether exposure of the gingival margins directly affects laypersons' and orthodontists' perceptions.: To evaluate the impact of vertical position and gingival zenith level of maxillary canine on smile esthetics as judged by orthodontists, general dentist and laypersons: This is a qualitative, descriptive cross-sectional study aimed at studying the role of vertical position and gingival zenith level on the smile esthetic perception. A smiling photograph of a male subject with and without exposing the gingival zeniths was selected, and vertical positions and gingival zenith levels of canine were symmetrically modified in increments of 0.5 mm, creating two sets of 4 new modified images varying from 1.0 mm of intrusion to 1.0 mm of extrusion and 1.0 mm of increasing and decreasing the height with gingival exposure. The total of 15 images were evaluated by 40 orthodontists, 40 general dentists and 40 laypersons, who determined the level of attractiveness of each smile on a visual analog scale.: Both smile arc ( <0.05) and gingival display amount ( <0.001) had statistically significant influences on the perception of smile attractiveness. Smile attractiveness scores with reference to gingival display amount showed a statistically significant ( <0.001) difference between the rater groups. A significant ( <0.05) interaction between smile arc and gingival display amount was observed. No significant difference were noted with standard smiles and intrusion smiles. Also, with 0.5mm extrusion and intrusion images in low smile. The intra-evaluator groups showed no significant difference between intrusion and extrusion high as well as low smile images, (value<0.05 for all). significant difference was seen in extrusion and intrusion high smile at 0.5mm and low smile images at 1mm level, extrusion and intrusion low smile images at 0.5mm level, (value>0.05 for all), significantly higher intrusion and extrusion high smile images at 0.5mm level, (-value<0.05 for all). extrusion and intrusion high as well as low smile images at 1mm and 0.5mm levels, (-value<0.05 for all).: Orthodontists were more critical in their assessments. There were no differences in the esthetic evaluations of smiles with and without gingival margin exposure for both groups of evaluators. For all the three evaluator groups, the most attractive ones were the standard smile and smile with the intrusion of 0.5 in high smile, standard and extrusion of 0.5 mm in the low smile group 0.5 mm of increased gingival zenith level (GZL) as perceived by orthodontists and general dentists, while for laypeople it was the standard smile. The unattractive smiles have extrusion and intrusion of 1mm for all the three evaluator groups 1 mm followed of decreased GZL of canine, for orthodontists and general dentist with 1mm increased. Laypeople, orthodontists scored all the images more critically by giving lesser scores compared to the general dentists and laypeople.

Clinical audit of an artificial intelligence (AI) empowered smile simulation system: a prospective clinical trial

Smile aesthetics is an important factor to consider during orthodontic treatment planning. The aim of the present study is to assess the predictability of Invisalign SmileView for digital AI smile simulation in comparison to actual smile treatment outcomes, using various smile assessment parameters. A total of 24 adult subjects (12 females and 12 males; mean age 22 ± 5.2 years) who chose to be treated using Invisalign were prospectively recruited to have their pretreatment smiles captured using the Invisalign SmileView to simulate their new smiles before treatment was started. Patients were then treated using upper and lower Invisalign aligners with average treatment time of 18 ± 6 months. Full post-treatment records were obtained and full smile frame images of simulated smile and actual final smile of each subject were evaluated by an independent examiner using an objective assessment sheet. Ten smile variants were used to assess the characteristics of the full smile images. Significance level was set at P < 0.05. The ICC for the quantitative parameters showed that there was an overall excellent & good internal consistency (alpha value > 0.7 & > 0.9). The Independent t test was performed amongst the quantitative variables. The P value was not significant for all except maxillary inter canine width (P = 0.05), stating that for the five variables namely; philtrum height, commissure height, smile width, buccal corridor and smile index, actual mean values were similar to the simulation mean values. For the qualitative variables, the Kappa value ranged between 0.66 and − 0.75 which showed a substantial level of agreement between the examiners. Additionally, the Chi square test for the qualitative variables, revealed that the P value was found to be significant in all except lip line. This implies that only the lip line values are comparable. More optimal lip lines, straighter smile arcs and more ideal tooth display were achieved in actual post treatment results in comparison to the initially predicted smiles. Five quantitative smile assessment parameters i.e., philtrum height, commissure height, smile width, buccal corridor, and smile index, could be used as reliable predictors of smile simulation. Maxillary inter canine width cannot be considered to be a reliable parameter for smile simulation prediction. A single qualitative parameter, namely the lip line, can be used as a reliable predictor for smile simulation. Three qualitative parameters i.e., most posterior tooth display, smile arc, and amount of lower incisor exposure cannot be considered as reliable parameters for smile prediction.Trial Registration number and date: NCT06123585, (09/11/2023)

Layperson assessment of smile lines and upper lip combined images in smile esthetics

The esthetic assessment of smile lines by laypersons is a subject of ongoing debate. However, smile lines often appear with different types of upper lip curvature, which further complicates the esthetic assessment process, and studies on this combination are lacking. The purpose of this clinical study was to investigate a layperson's esthetic perception of smile lines and upper lip combined images. Twenty-six smile images resulting from combinations of 3 upper lip types, 4 anterior smile line types, and 3 posterior smile line types were generated by an image editing software program. Eighty-three laypersons (39 men and 44 women; 18 to 35 years of age) completed rating images using a visual analog scale. Unattractive smiles were designated to be those with scores <50 and attractive ones with scores ≥50. Data were analyzed using 1-way analysis of variance and Bonferroni post hoc tests (α=.05). High anterior smile line with gingival display >4mm obtained significantly lower scores of <50 when combined with all upper lip curvatures (upward: 28.29 ±22.79, straight: 38.74 ±23.00, downward: 30.67 ±22.25, P<.01). High anterior smile lines with gingival display ≤4mm combined with upward and straight upper lip curvature images obtained significantly higher scores, and all were ≥50 (upward: 63.24 ±22.22, straight: 61.40 ±21.58, P<.01). From a layperson's perspective, high anterior smile lines with gingival display >4mm combined with any lip type were determined to be unattractive. If gingival display was ≤4mm combined with both upward and straight lip types, the smile was assessed as attractive.

Smile esthetics perception by the general population among different age groups in tiruchengode

To evaluate the smile esthetic perception on varying gingival display and black triangles among individuals aged between 18-35 and 36-50 using a visual analog scale (VAS). To evaluate the two variables (gingival display and Black triangle), a photo album is created that consist of two sets of photos which included six different photographs in each set. The frontal view of young adult female smile was selected for evaluating the esthetic perception. The smile features in the photographs is digitally altered using Adobe Photoshop CS6. Black triangles images are created using 0.5-mm increments. The gingival display by decreasing (−) the distance (2.0 and 4.0 mm) and increasing (+) the distance (2.0, 4.0, and 6.0 mm). The photographs are printed on photographic paper to create a photo album and coded from 1 to 6 and the scoring was done using a 10 cm visual analog scale (VAS). The participants are asked to mark the VAS score according to the attractiveness of each smile image separately with individual ratings.The comparisonofsmile esthetic perception among age groups was done using the Mann-Whitney U test. On comparing, the results revealed that laypeople with 18-35 yrs have given more scores for 0 mm Black triangle and for 2 mm gingival display which showed statistically significant results. Comparison of images among different age groups does not show significant results. The impact on the perception of smile esthetics vary among different age groups in terms of gingival display and black triangle.

Three-dimensional evaluation of social smile asymmetry in patients with unilateral impacted maxillary canine: a 3D stereophotogrammetry study.

This study aimed to evaluate social smile asymmetry in patients with unilateral impacted maxillary canine on 3D stereophotogrammetric images. The 3D social smile images of participants with unilateral impacted maxillary canine (n:20) and without impaction as a control group (n:20) were included. The images were recorded with a hand-held 3D stereophotogrammetry device (Fuel3D® Scanify®) and Geomagic Essentials 2 reverse engineering software were used for analyses. After the orientation process of the 3D records, the tissues around the smile area were divided into five morphological regions: cheek, upper lip lateral and medial, and lower lip lateral and medial. The deviation margins in the negative and positive directions for the 95% mesh rate and the total percentages of meshes between - 0.5- and + 0.5-mm deviations were calculated. ICC, paired samples t test, independent samples t test, and the Mann-Whitney U test were used for statistical analyses. In individuals with impacted canine, the amount of maximum positive deviation in the upper lip medial was 5.64mm ± 1.46 and maximum negative deviation was - 4.6mm ± 1.17. In the control group, mean of deviation limits for all parameters was less than 1.19mm ± 2.62, while in individuals with unilateral impacted maxillary canine, the maximum value was 8.34mm ± 2.23. The mesh percentage between - 0.5 and 0.5-mm deviations was over 95% in all morphological areas in the control group, while in the impacted canine group, the number of meshes within the specified deviation limits was less than 95%. Individuals with unilateral impacted maxillary canine exhibit greater asymmetry in social smile compared to the control group, with the asymmetry being most prominent near the corners of the mouth and cheeks. Amount of asymmetry was higher in impaction group compared to the control group in social smile. The quantification of a possible smile asymmetry due to the impacted canine is crucial for the diagnosis and treatment planning of orthodontic and/or orthognathic cases for ideal aesthetic results. Hence, smile asymmetry should not be overlooked and should be considered in diagnosis and treatment planning.

Facial Mimicry and Social Context Affect Smile Interpretation

Theoretical accounts and extant research suggest that people use various sources of information, including sensorimotor simulation and social context, while judging emotional displays. However, the evidence on how those factors can interplay is limited. The present research tested whether social context information has a greater impact on perceivers’ smile judgments when mimicry is experimentally restricted. In Study 1, participants watched images of affiliative smiles presented with verbal descriptions of situations associated with happiness or politeness. Half the participants could freely move their faces while rating the extent to which the smiles communicated affiliation, whereas for the other half mimicry was restricted via a pen-in-mouth procedure. As predicted, smiles were perceived as more affiliative when the social context was polite than when it was happy. Importantly, the effect of context information was significantly larger among participants who could not freely mimic the facial expressions. In Study 2 we replicated this finding using a different set of stimuli, manipulating context in a within-subjects design, and controlling for empathy and mood. Together, the findings demonstrate that mimicry importantly modulates the impact of social context information on smile perception.

Role of Dentofacial Harmony among Young and Old Adult Females in Smile Perception of Dental Specialists and Laypeople: A Cross-Sectional Study.

The purpose of this study was to determine whether balance and harmony of the face, when seen as a whole, alter the smile perception as compared to a lone standing smile in female subjects of two age groups and to identify parameters of dental composition and dentofacial harmony associated with the smile perception of dental specialists (DS) and laypeople (LP). A cross-sectional study. Twenty-nine DS and 29 LP scored the smile attractiveness of 84 full-face images (FFIs) and corresponding smile images (SIs) of young adults (YA: 20-29 years) and old adults (OA: 50-59 years), using the Visual Analogue Scale. Smile analysis software (Planmeca Romexis®Smile-Design) was used to measure 10 parameters of dental composition and dentofacial harmony in FFI. Independent t-test and Pearson's correlation coefficient (r) were used to analyze the data. A significant difference was not seen between the smile attractiveness scores of FFI and SI in both raters and age groups. Significant differences were observed between DS and LP in the YA group. The OA group was rated significantly higher than the YA group. The correlation between smile attractiveness scores and each of the nine dentofacial parameters was not significant (P < 0.05). Framing of images did not significantly alter smile perception. FFI received higher scores than SI, and raters were more critical of the YA group. Professional training of raters and an interplay of smile and facial attractiveness of the female subjects contributed to the smile perception of raters. No parameters of dental composition or dentofacial harmony significantly associated with smile attractiveness were identified.

The buccal corridor as a possible morphological risk indicator for sleep disordered breathing.

To explore a possible morphological relationship between buccal corridor, gingival display, transpalatal molar width, palatal height, and a cephalometric measurement (PV-A Line) as a risk indicator for sleep-disordered breathing. Thirty subjects were enrolled. Full face maximum smile images and CBCT scans were taken. A Pearson correlation coefficient was used to identify any relationships between the variables. No correlations were identified between any of the variables investigated in this study as they relate to risk factors for sleep-disordered breathing. The amount of buccal corridor space in relation to a patient's smile and the amount of gingival display does not appear to be a reliable metric in identifying certain morphological risk factors for sleep-disordered breathing. Assessing the amount of buccal corridor space in relation to a smile does not appear to be a reliable predictor of morphological risk for certain risk factors of sleep-disordered breathing. In addition, utilizing the amount of gingival display in a patient's maximum smile does not appear to relate directly to risks in sleep-disordered breathing. Other tests and discovery may be necessary to identify these types of patients.

ANALYSIS OF THE ANTHROPOMETRIC MEASUREMENTS OF THE SMILE USING 3D STEREOPHOTOGRAMMETRY

3D stereophotogrammetry makes the analysis of facial soft tissues possible, and has the potential to contribute to human identification processes. Nowadays, the images available through social networks are composed of a significant amount of smile photos, making techniques such as 3D stereophotogrammetry relevant. The objective of the present study was to quantitatively analyze the anthropometric measurements of the smile through 3D stereophotogrammetry, including area, angular, and linear measurements. Anatomical landmarks were used to make possible the area, angular, and linear measurements. The sample consisted of 27 volunteers, 13 female and 14 male, both in the 19-25 age group, resulting in a mean age of 22.3±1.9 and 23.3±1.5, respectively. The anatomical landmarks were marked on the face of the volunteers using a black eyeliner, and the photographs were taken using the 3D stereophotogrammetry technique (Vectra H1, Canfield, NY, USA), being 3 photographs with a spontaneous smile and 3 at rest, right lateral, left lateral and frontal of each. Among the results of the comparison between genders and the photo/smile relation of the statistical analysis, variables such as the mentolabial angle and the vermilion height of the upper lip showed significant p-values of 0.046 and 0.014, respectively. It can be concluded that anthropometric measurements of three-dimensional smile images can be performed with the use of 3D stereophotogrammetry, with the purpose of contributing to facial identification methods.

The effect of torque and vertical position of maxillary canine on smile esthetics

Regarding the key role of the maxillary canine in dynamic occlusion and smile esthetics, this study investigated the relation between smile esthetics and maxillary canine torque and vertical position from the viewpoint of orthodontists, general dentists, and laypersons. In this descriptive cross-sectional study, the close-up smile images have been changed using Adobe Photoshop (Adobe Systems, San Jose, Calif). Then, groups of 21 orthodontists, 20 general dentists, and 33 laypersons evaluated the smile attractiveness of the images using a digital version of a visual analog scale. Statistical analysis was performed using SPSS software (version 25; IBM, Armonk, Calif) and Shapiro-Wilk, analysis of variance, and Tukey post-hoc statistical tests. The significance level was set at 0.05. There was no significant difference in the mean score between the 3 groups of observers regarding the changes in the canine vertical position in none of the variations (P>0.05). Regarding variations in torque, there was a significant difference between the 3 groups of observers in the bilateral 5° torque change. (P= 0.020). Unilateral changes in the vertical position had lower scores, which shows that symmetry is very important in smile esthetics. In addition, laypersons did not find torque changes ranging between -15° to 15° a significant factor in smile esthetics. Overall, some adherence to these values will be acceptable in dental treatments.

Clear Aligners and Smart Eye Tracking Technology as a New Communication Strategy between Ethical and Legal Issues.

Smart eye-tracking technology (SEET) that determines visual attention using smartphones can be used to determine the aesthetic perception of different types of clear aligners. Its value as a communication and comprehension tool, in addition to the ethical and legal concerns which it entails, can be assessed. One hundred subjects (50 F, 50 M; age range 15-70) were equally distributed in non-orthodontic (A) and orthodontic (B) groups. A smartphone-based SEET app assessed their knowledge of and opinions on aligners. Subjects evaluated images of smiles not wearing aligners, with/without attachments and with straight/scalloped gingival margins, as a guided calibration step which formed the image control group. Subsequently, the subjects rated the same smiles, this time wearing aligners (experimental images group). Questionnaire data and average values for each group of patients, and images relating to fixation times and overall star scores, were analyzed using these tests: chi-square, t-test, Mann-Whitney U, Spearman's rho, and Wilcoxon (p < 0.05). One-way ANOVA and related post-hoc tests were also applied. Orthodontic patients were found to be better informed than non-orthodontic patients. Aesthetic perception could be swayed by several factors. Attachments scored lower in aesthetic evaluation. Lips distracted attention from attachments and improved evaluations. Attachment-free aligners were better rated overall. A more thorough understanding as to the opinions, expectations and aesthetic perception of aligners can improve communication with patients. Mobile SEET is remarkably promising, although it does require a careful medicolegal risk-benefit assessments for responsible and professional use.

The Influence of Social Network Content on the Perception of Smiles-A Randomized Controlled Trial.

Background: This randomized trial’s objective was to investigate the impact of social network content on the perception of smiles among specialists, doctors, students of dental medicine, and laypeople. Method: A sample of 360 respondents was shown 7 digitally altered photographs of smiles (85.63% female, 14.37% male). Dental specialists, dentists, dental students (first to third year and fourth to sixth year), and laypeople made up the sample. Respondents were asked to rank the images on a scale of 1 to 10, starting with the least appealing and moving up to the most attractive, using a Google Form. Respondents were divided into experimental and control groups at the end of the following month by random selection. The experimental group followed an Instagram profile posting two images of beautiful smiles for seven days, while the control group received no intervention at all. Both groups then completed the same questionnaire again. The comparison of esthetic scores between the experimental and control group was performed using the Mann–Whitney U-test and the difference in test responses between the starting point of the measurement and after exposure to perfect content on social media within individual groups was tested with the Wilcoxon paired-samples test. When comparing the absolute difference of scores, the Mann–Whitney U-test and the Kruskal–Wallis test were used. Results: Respondents in the experimental group rated the rounded embrasures of the incisors with lower esthetic scores compared to the control group that was not exposed to images on the Instagram social network. In those exposed to Instagram (experimental group), laypeople showed significantly greater satisfaction with their own smile after the exposure to Instagram, whereas no such difference was present in the control group. Conclusions: The content of social networks potentially has an influence on smile perception, most visible in the perception of incisal embrasures and self-perception of smile.

Perception of Smile Aesthetics and Attractiveness among Saudi Females

Smile aesthetic, known as the static and dynamic relationship of the dentition and supporting structures to the facial soft tissues, is one of the most important elements of facial attractiveness. The objective of the study was to assess the perception of smile aesthetics and attractiveness through digital image manipulation of aesthetic variables and to compare those perceptions according to diverse sociodemographic data among female Saudi laypeople attending the dental clinic. A crosssectional study of 193 female Saudi participants were randomly selected and consented to answer the study questionnaire. Nine smile photograph images were created to compare different smile aesthetic perceptions. Two groups were recruited: 120 participants in the first group (under 30 years old) and 73 participants in the second group (30 years old or above). All participants in both groups were asked to choose the attractiveness of each smile image using multiple-choice options. A statistically significant finding showed that normal buccal corridors were chosen as the most attractive smile by 42.5% of the participants in the younger group and by a significantly higher ratio of the participants with a bachelor’s degree or higher level of education at 49% (p &lt; 0.05). Laypeople’s preferences regarding smile attractiveness vary, but a normal appearance was the ideal choice for the majority. Orthodontic treatment should consider the general sociocultural understanding of smile perception.

Comparison between orthodontist, general dentist, and layperson in the perception of pink esthetics on smile: A cross-sectional study

Objectives: Smile designing has become an essential part of dental training and a beautiful smile not only adds to the esthetics of the face but also conveys emotions and augments the self-esteem of an individual. A beautiful smile is achieved by well-balanced pink and white esthetics. This study was designed to evaluate the difference in perceptions of orthodontists, general dentists, and laypersons to alterations in gingival characteristics on smile. Material and Methods: Smile images were modified intentionally to obtain the desired variations in gingival features such as color and contour of free gingival margins, inflammation, pigmentation, gingival margins with or without recession, zenith, and interdental papilla. A total of 51 images were rated by orthodontists, general dentists, and laypersons using Q sort methodology. Results: Variations in the position of free gingival margin with recession was most negatively ranked gingival factor by orthodontists, general dentists, and laypersons followed by variations in the position of interdental papilla. Position of free gingival margin without a recession, color changes due to pigmentation, and inflammation were moderately ranked. Control images and altered gingival zenith images were most positively ranked. Bilateral changes were perceived more readily compared to unilateral in factors such as a black triangle, zenith position, pigmentation, inflammation, and recession. Conclusion: Orthodontists seem to be less tolerant in their evaluations in comparison to general dentists and laypersons. The findings of this study point toward a crucial fact that smile designing should focus on parameters that are perceived readily by the public in general.

Assessment of the Perception of Aesthetics and Smile Attractiveness among Dental and Health Students

A modified intraoral smile image of an orthodontic patient having seven different clinical cases along with the questionnaire to among dental students and other health collages at Taif University, Kingdom of Saudi Arabia, was given to participate in this study. A total of 120 dental students and 307 students from other health colleges participated in the study.

Analisis Algoritma Shi-Tomasi Dalam Pengujian Citra Senyum Pada Wajah Manusia

Problems in image processing to obtain the best smile are strongly influenced by the quality, background, position, and lighting, so it is very necessary to have an analysis by utilizing existing image processing algorithms to get a system that can make the best smile selection, then the Shi-Tomasi Algorithm is used. the algorithm that is commonly used to detect the corners of the smile region in facial images. The Shi-Tomasi angle calculation processes the image effectively from a target image in the edge detection ballistic test, then a corner point check is carried out on the estimation of translational parameters with a recreation test on the translational component to identify the cause of damage to the image, it is necessary to find the edge points to identify objects with remove noise in the image. The results of the test with the shi-Tomasi algorithm were used to detect a good smile from 20 samples of human facial images with each sample having 5 different smile images, with test data totaling 100 smile images, the success of the Shi-Tomasi Algorithm in detecting a good smile reached an accuracy value of 95% using the Confusion Matrix, Precision, Recall and Accuracy Methods.

Smile microesthetics as perceived by dental professionals and laypersons.

To evaluate and compare the perception of different dental professionals and laypersons toward altered gingival characteristics (microesthetics) and to identify those characteristics that are most negatively and positively rated. A smiling photograph of a female dental student was selected and digitally manipulated to create changes in different microesthetic parameters. These altered images were rated by the following five groups: 120 orthodontists, 45 periodontists, 49 prosthodontists, 130 general dentists, and 172 laypersons. Smile esthetics scores were calculated, and comparisons between groups were performed using the univariate general linear model. The presence of black triangles between the upper incisors was the most negatively rated, and the ideal smile was the most positively rated. Significant differences were detected in the rating scores among the different study groups (P < .05). Orthodontists, prosthodontists, and general dentists scored the presence of a black triangle in the smile as the least attractive, whereas periodontists and laypersons perceived the inflamed gingiva and pigmented gingiva as the least attractive, respectively. Dental specialists tended to give the altered smile images lower scores than the laypersons. The ideal smile and that with black triangles between the upper incisors were rated as the most and the least attractive smiles, respectively. Orthodontists, prosthodontists, and general dentists scored the presence of black triangles in the smile as the least attractive, whereas periodontists and laypersons perceived the inflamed gingiva and pigmented gingiva as the least attractive smiles, respectively. Dental specialists tended to give the altered smile images lower scores than the laypersons.

Analysis of the esthetic preferences of Spanish laypersons and dentists regarding the different width proportions of the maxillary anterior teeth

Statement of problemMultiple esthetic width proportions have been described for maxillary anterior teeth. However, the esthetic characteristics of each have not been compared simultaneously to determine which proportion is preferred by dentists and laypersons. PurposeThe purpose of this study was to evaluate the preferences of dentists and laypersons with respect to internationally recognized dental esthetic proportions. It also sought to determine whether a relationship existed among dentists' preferences as per their specialty and among laypersons as per their academic field. Material and methodsTwo smile images, one male and one female, were digitally modified to meet the golden proportion and the recurring esthetic dental (70%) and golden percentage. The 2 resulting sets of images (original images and digitally altered ones) were presented to dentists and laypersons through a Web-based survey site. The Pearson chi-squared and Fisher tests were used to assess the differences in the esthetic preferences among the groups (α=.05). ResultsA total of 363 answers were obtained from dentists and 750 from laypersons. Both groups considered recurring esthetic dental to be the most esthetic proportion and golden proportion to be the least esthetic proportion. The dentists' preferences as per their specialty followed the same trend, whereas the laypersons' preferences were more scattered according to their academic field. The recurring esthetic dental proportion was preferred in images of both sexes, golden proportion smiles were the least preferred for female smiles, and golden percentage was the least preferred for male smiles. ConclusionsThe results obtained indicated that the preferred esthetic proportion both for dentists and laypersons was the recurring esthetic dental 70%, with the dentists’ specialty or laypersons branch of knowledge not affecting choice.

Perception of Smile Aesthetics : A Cross-Sectional Comparative Evaluation of Senior Dental and Medical Students

Objectives: Acquiring the ability to identify deviations in dental aesthetic norms has been considered as an essential skill for the development of a dental professional. The timing and quality of this development of aesthetic perception has not been explicitly discussed in the dental education literature. This study aimed to evaluate the impact of dental training on the development of smile aesthetic perception, and to compare this perception between dental students and medical students in a similar cohort. Methods: One-hundred dental and medical students were invited to complete a self-administered questionnaire, designed to evaluate eight images; using a visual analogue scale (1 least attractive; 100 most attractive). The students rated the smile aesthetics of one ‘model’ smile image, and seven digitally modified smiles representing major variations in smile features. Data were analyzed using the independent student’s t-test. Results: forty-four male and fifty-five female participants were successfully recruited, with a response rate of 99%. Dental students’ ratings of smile aesthetics were significantly lower than medical students for seven of the eight images (p < 0.05). This difference was greatest for the model smile image, and least for the diminutive lateral incisors image. There were no statistically significant gender-related differences. Conclusions: Within the limitation of this study, the dental curriculum has a significant impact on developing students’ perception of dental aesthetics. Longitudinal studies with larger samples sizes, are needed to examine if progress through the dental curriculum affects students’ perception of dental aesthetics.