The impact of dental midline angulation towards the facial flow curve on the esthetics of an asymmetric face: Perspective of laypeople and orthodontists.

PURPOSE: The objective of the present article was to evaluate the impact of dental midline angulation in asymmetrical faces. MATERIALS AND METHODS: A full-portrait image was used to create a set of digitally modified images with a different degree of facial asymmetry, towards the right and the left side of the face respectively. Half of the images were designed with an equivalent angulation of the dental midline in respect to the curve of the lower third of the face and half of them without. Through a web survey, 250 laypeople and 250 orthodontists were asked to assess the attractiveness of each image separately. RESULTS: As the asymmetry of the face was increased, facial attractiveness was further decreased both for laypersons and orthodontists. For each one of the modified images, when the dental midline was following the curve that was formed from the inclination of the simulated asymmetry of the face, the smile attractiveness scores were significantly higher compared to a straight dental midline. CONCLUSION: Facial asymmetries derived from the inclination of the nose, the chin and the commissural line of the lips can significantly affect the smile attractiveness. An orientation of the dental midline towards the facial asymmetry in order to follow the facial curve, can be beneficial for the smile attractiveness compared to a perpendicular to the face dental midline. During the design of a smile, clinicians have to take into consideration deviations in facial midline, in order their restorations to be in harmony with the rest of the face. CLINICAL SIGNIFICANCE: During the design of a smile, clinicians have to take into consideration deviations in the facial midline, in order their restorations to be in harmony with the rest of the face.

Perception of smile attractiveness among laypeople and orthodontists regarding the buccal corridor space, as it is defined by the eyes. An innovated technique.

OBJECTIVE: To investigate whether there is a relationship between the distance between the iris and pupil with the ideal size of buccal corridors. MATERIALS AND METHODS: A full-portrait image of a male Caucasian was used to create a set of 11 digitally modified images with different buccal corridor space. A web-based cross-sectional study was designed and distributed via an online survey to 200 laypeople and 200 orthodontists to assess image attractiveness, using a Visual analogue scale. For the statistical analysis, Wilcoxon signed-rank and Mann-Whitney U tests were used. The significance level was set at p < 0.05. RESULTS: The response rate for laypeople was 70% (n = 139), while the rate for orthodontists was 73% (n = 146). For the layperson group, the maximum smile attractiveness score was 10% of buccal width reduction, compared to the iris-pupillary distance, while for the orthodontists, it was 20%. The attractiveness of the smile was significantly reduced in both groups when the buccal corridor width was increased in comparison to the iris-pupillary distance. CONCLUSION: The length between the mesial part of the iris and the distal of the pupil, may constitutes a landmark for the estimation of the desired width of the buccal corridor. CLINICAL RELEVANCE: Inter iris-pupillary distance can be the starting point in the smile designing process, in order to perform a facial driven selection of buccal corridor size.

The Influence of Gingival Exposure on Smile Attractiveness as Perceived by Dentists and Laypersons.

Background and Objectives: Smile is an important mark of beauty, and smile attractiveness can be influenced by various factors, one of these being the amount of gingival exposure. The aim of this research was to evaluate the perception of an ideal gingival exposure in smile in a sample of Romanian dentists and laypersons, and to find out what is the most important aspect that influences the smile perception for the respondents included in the study sample. Materials and Methods: An online survey was conducted between 3 February 2020 and 31 October 2020. The authors developed a short questionnaire consisting of 7 items. The first four items investigated the respondents' age, gender, profession and whether or not they underwent an orthodontic treatment in the past. For items 5 and 6, participants had to choose the most and the least attractive amount of gingival exposure, and for the last item they had to choose the factor that mostly influences the smile attractiveness in their opinion. Results: 235 questionnaires remained in the study. The sample consisted of 194 women and 41 men, 162 laypersons and 73 dentists. The average value for the most attractive amount of gingival exposure was −0.57 ± 2.407 mm, with a median value of 0 mm while the average value for the least attractive amount of gingival exposure was 1.43 ± 3.785 mm, with a median value of 4 mm. The differences between the most or least attractive gingival exposure perceived by the participants were not significant according to gender or professional category (p > 0.05), but, when compared between having or not having an orthodontic treatment in the past the differences were statistically significant (p < 0.05). As such, participants who had an orthodontic treatment in the past perceived a significantly higher value for the most attractive gingival exposure, and a significantly higher value for the least attractive gingival exposure (p = 0.026) than the participants who didn't have an orthodontic treatment in the past. As for the factor that mainly influences smile attractiveness, laypersons chose significantly more frequent white teeth or aligned teeth (96%, 71.7%) while dentists chose significantly more frequent a gingival exposure between 0−3 mm (70.4%) as smile factors for an aesthetic smile (p < 0.001). Conclusions: In this study sample, the respondents considered that the most attractive smile involved a covering of 0.57 mm (in average) of the upper incisors by the upper lip. Although smile attractiveness did not appear to be influenced by gender or profession in this study population, it was influenced by previous orthodontic treatment. The participants' roles of dentist or layperson influenced the factors chosen for an aesthetic smile.

Smile Reproducibility and Its Relationship to Self-Perceived Smile Attractiveness.

The reproducibility of facial expressions has been previously explored, however, there is no detailed information regarding the reproducibility of lip morphology forming a social smile. In this study, we recruited 93 young adults, aged 21−35 years old, who agreed to participate in two consecutive study visits four weeks apart. On each visit, they were asked to perform a social smile, which was captured on a 3D facial image acquired using the 3dMD camera system. Assessments of self-perceived smile attractiveness were also performed using a VAS scale. Lip morphology, including smile shape, was described using 62 landmarks and semi-landmarks. A Procrustes superimposition of each set of smiling configurations (first and second visit) was performed and the Euclidean distance between each landmark set was calculated. A linear regression model was used to test the association between smile consistency and self-perceived smile attractiveness. The results show that the average landmark distance between sessions did not exceed 1.5 mm, indicating high repeatability, and that females presented approximately 15% higher smile consistecy than males (p < 0.05). There was no statistically significant association between smile consistency and self-perceived smile attractiveness (η2 = 0.015; p = 0.252), when controlling for the effect of sex and age.

Morphological features of smile attractiveness and related factors influence perception and gingival aesthetic parameters.

INTRODUCTION: In addition to understanding the basic standards of a smile and patient's opinion, dentists should take into account smile aesthetics, an essential factor for optimal outcomes. This study aimed to evaluate the factors that affect the perception of an aesthetic smile and determine its morphological characteristics and measure the gingival aesthetic parameters. METHODS: In all, 200 Vietnamese aged 18-35 years were recruited to have their spontaneous smiles captured. These smile images were assessed by 50 laypersons and 50 dentists using a visual analogue scale measurement. The images were analysed to evaluate perceptions of evaluators, determine smile attractiveness, and measure gingival aesthetics. RESULTS: The difference in the judgements of laypersons and dentists, males and females, and laypersons aged 18-25 and 26-35 years were nonsignificant. High or average anterior smile line, parallel smile arc, upward upper lip curvature, second premolars as the posterior-most teeth displayed, smile index of 5.23-5.63, and dynamic smile symmetry of 1 were scored highly on smile attractiveness. The following maxillary gingival aesthetic parameters were preferred: gingival zenith (GZ) of the canine 0.72-0.75 mm apical to the GZ of the central incisor; GZ of the lateral incisor 0.66 mm coronal to the gingival line; gingival line angle of ∼87°; for the central incisor, lateral incisor, and canines, distance from the GZ to the long axis of 1, 0.4, and 0 mm, respectively; interdental papilla height of 4.25, 3.60, and 3.85 mm, respectively; ratio of the distance from the GZ and the interdental papilla tip to the incisal edge of ∼1.74-1.77 mm. CONCLUSIONS: Factors including profession, gender, and age of evaluators had almost no impact on their perception of aesthetics. Smile attractiveness characteristics and gingival aesthetic parameters have clinical applicability for patient care.

Influence of lightness difference of single anterior tooth to smile attractiveness.

OBJECTIVES: To evaluate the influence of lightness difference of a single anterior maxillary tooth on difference smile attractiveness. METHODS: A frontal view full-portrait image of a smiling male Caucasian, was digitally modified altering a single tooth, creating a series of images with varying lightness (ΔL) for the maxillary central, lateral and canine. A total of 160 participants (80 dentists, 80 laypersons) were asked to fill out a Visual Analog Scale questionnaire for every image recording smile attractiveness. RESULTS: For central incisors ΔL≥1 negatively affected attractiveness. There was a higher tolerance for lightness mismatch when one lateral incisor is lighter and the same applies when the canine was darker. Difference in lightness affected smile attractiveness both for dentists and laypersons. No difference between males and females was observed for the dentists. For laypersons, females perceived smiles with lightness difference as significantly less attractive compared to males. Dentist's age did not affect smile attractiveness perception. Younger laypersons perceived darker color, as less attractive. CONCLUSIONS: Changes in lightness of a single anterior tooth significantly affected smile attractiveness in a different way for the central vs lateral vs canine. For the dentists, age and gender did not significantly affect smile perception, in contrast to laypeople. CLINICAL SIGNIFICANCE: Lightness differences of a single anterior tooth affects smile attractiveness.

The relationship of tooth shade and skin tone and its influence on the smile attractiveness.

OBJECTIVE: The purpose of this clinical study was to determine if skin tone and tooth color had the same influence on smile attractiveness. MATERIALS AND METHODS: A woman's smile photograph was digitally manipulated to create a range of images with varying colors. The skin shade was modified to create four tones (p1: light, p2: light medium, p3: medium dark, p4: dark) using the L'Oreal True Illusion shade as a guide. The tooth shade was modified in four different tones: A1, A2, A3, A4 using the VITAPAN Classical shade guide to produce 16 images. A sample of 328 participants rated each image for attractiveness by means of a visual analog scale (VAS). Comparison among groups was performed with a 2-way ANOVA adjusted for multiple comparisons with the Bonferroni test (α = .05). RESULTS: Image (p3-a1) showed the highest VAS values, while image (p1-a4) obtained the lowest, (Bonferroni Test: a1 vs a2, a3, a4 P < .001; p3 vs p1, p2, p4 P < .001). Analysis performed for age, sex, level of education, and laypeople/dentists were not statistically significant (P > .05). CONCLUSIONS: Variations in tooth and skin tone can significantly influence the perception of smile attractiveness. In the tested conditions, a brighter tooth shade significantly affected the attractiveness of the smile independently from skin tone. CLINICAL SIGNIFICANCE: Understanding patient and dentist perception of the attractiveness of a smile with the important role-played by skin tone, may help clinicians to better identify teeth shade, helping delivery of tailored prostheses and esthetic restorations.

Self-perception of smile attractiveness as a reliable predictor of increased patient compliance with an orthodontist.

BACKGROUND: Predicting the cooperation of orthodontic patients seems to be of the utmost importance for successful results in treatment with removable appliances, especially if their cost is to be covered from public funding. Therefore, the issue of unbiased pre-treatment assessment of cooperation still calls for an investigation. OBJECTIVES: The objective of this study was to check whether smile attractiveness and its importance, subjectively evaluated by the patients/their caregivers, are reliable predictors of a patient's compliance during treatment with removable appliances. MATERIAL AND METHODS: The study group comprised 97 patients aged 9-12 years, treated with active plates or twin-blocks, equipped with the TheraMon® system. Before treatment, the caregivers and the patients filled out the questionnaires ranking both of the investigated variables. After 9 months of treatment, we analyzed the correlations of the daily wear time (DWT) and other variables. RESULTS: The analysis revealed the following: no relevance of the DWT to the type of removable appliances; negative correlation between the DWT and smile attractiveness assessed by the children and their caregivers; evidently elongated DWT (up to 9.68 h in children), who, together with the caregivers, evaluated their smile attractiveness as poor; coherence of children's and their caregivers' responses evaluating smile attractiveness and its importance, as well as the lack of consistency when comparing responses provided separately by the children and their caregivers. CONCLUSIONS: Application of the TheraMon® sensors objectively proved that the patient's smile attractiveness ranked subjectively as low predicts the orthodontic patient's irreproachable cooperation. Therefore, our easy-to-use questionnaire calls for changing the protocol regarding the wearing time of removable appliances during treatment and introducing an evidence-based policy of reimbursement for such therapy from public funds. Further investigation of the effectiveness of removable appliances worn shorter than previously presumed and of the motivation to continue treatment, once smile attractiveness has been improved, is necessary.

Effect of the interproximal contact level on the perception of smile esthetics.

BACKGROUND: Many dental and facial components affect smile esthetics, and dental professionals' opinions regarding dental esthetics may not always coincide with the perceptions and expectations of the patients. OBJECTIVES: This work is designed to determine the dimensions of the interproximal contact areas that are considered the most or least attractive according to a group of laypersons, dentists and technicians. MATERIAL AND METHODS: Two photographs of female and male smiles showing a full smile were taken with a Nikon® camera and digitally altered using Adobe® Photoshop. The length of the interproximal contact areas was altered to generate 2 sets of images (3 images of the female and 3 images of the male smile in each set). A group of 40 laypersons, 40 dentists and 40 dental technicians were asked to select the most and the least attractive image in each set. RESULTS: An interproximal contact ratio of 50:40:30 [%] was the most attractive arrangement (40.00% and 38.33% for the female and male smiles, respectively). The 'reversed' ratio of 30:40:50 [%] was the least attractive to the participants (57.50% and 44.17% for the female and male smiles, respectively). There were differences in the rankings of the most and the least attractive smiles among the 3 groups of evaluators. CONCLUSIONS: The 'ideal' interproximal contact ratio of 50:40:30 [%] is perceived to be the most attractive. However, the smile esthetics perception among dental professionals is not always in agreement with the perception of laypersons.

Perception of smile attractiveness among orthodontists, restorative dentists, and laypersons in Saudi Arabia.

BACKGROUND: A smile is defined as a universal welcome. The perception of smile attractiveness is affected by the persons' social background and their own experiences. The existing literature states that orthodontists, restorative dentists, and laypersons have different opinions. AIMS: The aim of this study is to compare the perception of orthodontists, restorative dentists, and laypersons regarding smile esthetics. MATERIALS AND METHODS: A survey-based study was conducted. The target population was orthodontists, restorative dentists, and laypersons in Saudi Arabia. An electronic survey that included digitally altered photographs representing different smile parameters was designed by an Adobe Photoshop Certified Expert. Participants were asked to choose the most attractive smile in each question. RESULTS: Unilateral changes in the width or length of the central incisors were the least attractive among the three groups. About 38%, 48%, and 41% of the participating orthodontics, restorative dentists, and laypersons, respectively, found that wider buccal corridors were more attractive. Moreover, 27% of the laypersons found the reversed smile arc to be attractive. CONCLUSION: The tolerance level in evaluating the asymmetry and the width of the buccal corridors was similar for the three groups. Laypersons were less sensitive to the deviations from the ideal in the smile arc and the amount of lower lip coverage of the incisors. CLINICAL SIGNIFICANCE: Understanding the differences in the perception of smile attractiveness among orthodontists, restorative dentists and laypersons will undoubtedly be beneficial in diagnosis, setting treatment objectives and treatment planning.

Smile attractiveness perception regarding buccal corridor size among different facial types.

BACKGROUND: The width of the buccal corridor (BC) is one of the factors affecting smile attractiveness. OBJECTIVES: The aim of this study was to determine the effects of the BC size on the smile attractiveness of individuals with short, normal and long faces from the viewpoint of laypersons, general dentists and orthodontists. MATERIAL AND METHODS: Smiling photographs of male and female subjects who met the inclusion criteria were digitally altered to create 3 BC sizes (narrow: 2%; normal: 15%; wide: 28%) and 3 facial types defined by the facial index (FI) (short face: FI ≤ 83.9; normal face: 84.0 ≤ FI ≤ 87.9; long face: FI ≥ 88.0). Nine different combinations were made and the evaluators rated the overall attractiveness and acceptability of each smile on a 10-millimeter visual analog scale (VAS). RESULTS: A total of 53 raters (22 laypersons, 16 general dentists and 15 orthodontists) participated in this study. The orthodontists and general dentists had similar viewpoints and they preferred narrow and normal BCs over the wide ones in all facial types. Laypersons preferred normal BC for normal faces, while they did not distinguish different BCs in short faces. CONCLUSIONS: Variations in the BC size affect smile attractiveness in different facial types and wide BCs are attributed to the least attractive smiles. Due to the different viewpoints of laypersons and professionals in this regard, there is no justification for expanding the maxillary arch to achieve more attractive smiles.

Atratividade do sorriso: um método simples para melhorar a percepção visual do dentista: desenvolvimento e teste-piloto com estudantes de pós-graduação / Smile attractiveness: a simple method to improve the dentist's visual perception: development and pilot test with postgraduate students

Objetivos: melhorar a percepção do dentista sobre a atratividade do sorriso através de avaliações objetivas. Material e métodos: fotografias frontais de sorrisos (envolvendo a área dos caninos) foram aleatoriamente escolhidas e dispostas em dois sentidos verticais variados (nivelado, abaixo) numa guia personalizada contendo quatro molduras labiais do sorriso (fino, médio, grosso, invertido). Os aspectos que influenciam a atratividade do sorriso (PD = proporção dentária, PV = posicionamento vertical dentário, EL = espessura labial, FG = festonamento gengival) também foram incluídos e uma nota final geral atribuída ao sorriso geral (SG). Adicionalmente, o formulário do exercício continha a opção "existe um implante?" e "qual sua localização?". Todos os itens foram avaliados através de escalas de Likert. A prevalência de respostas foi calculada para cada item. O teste de Wilcoxon (alfa = 5%) foi usado para verificar a possibilidade de diferença de opinião entre os nivelamentos horizontais e para uma mesma moldura de sorriso. Os níveis de confiabilidade (concordância absoluta = ICC e responsividade = Cronbach alfa) também foram avaliados. Resultados: um teste-piloto foi conduzido com 16 estudantes. Trinta e duas combinações foto/moldura labial foram geradas e apresentadas de forma randomizada. A avaliação geral do sorriso ficou em: pobre (11/32), mediano (6/32), bom (15/32) e muito bom (1/32). O número de acertos da possível posição do implante foi 13 em 32 tentativas. Diferenças estatisticamente significativas entre os nivelamentos foram observadas nas situações 1/17 (p=0,0001), 13/29 (p=0,02), 2/18 (p=0,0002), 6/22 (p=0,0001), 14/30 (p=0,0001), 7/23 (p=0,01) e 15/31 (p=0,039). Os maiores coeficientes de ICC e Cronbach alfa foram vistos para o sorriso geral e FG. Conclusão: a percepção visual do dentista pode ser treinada mudando-se a moldura labial e o nivelamento vertical dos dentes e é influenciada pelo festonamento gengival. O teste se mostrou útil na verificação da atratividade do sorriso.

Objectives: to improve the perception of the dentist on the smile attractiveness through objective evaluations. Material and methods: frontal photographs of smiles (involving the canine area) were randomly chosen and arranged in two different vertical directions (leveled, below) in a personalized guide containing four lip architectures (thin, medium, thick, inverted). The aspects that infl uence the smile attractiveness (PD = dental proportion, PV = vertical tooth position, EL = lip thickness, GS = gingival scalloping) were also included and a general final score attributed to the general smile (SA). Additionally, the exercise form contained questions such as "is there an implant?" and "what is your location?". All items were assessed using Likert scales. The prevalence of responses was calculated for each item. The Wilcoxon test was used to verify the possibility of differences between the horizontal leveling for the same smile architecture. The reliability levels (absolute agreement = ICC and responsiveness = Cronbach alpha) were also evaluated. Results: a pilot test was conducted with 16 students. Thirty-two photos/lip architecture combinations were generated and presented at random. The overall smile rating was: poor (11/32), average (6/32), good (15/32), and very good (1/32). The number of positive responses for implant position was 13 in 32 trials. Statistically significant differences were observed in the combinations 1/17 (p=0.0001), 13/29 (p=0.02), 2/18 (p=0.0002), 6/22 (p=0.0001), 14/30 (p=0.0001), 7/23 (p=0.01) and 15/31 (p=0.039). The highest ICC and Cronbach alpha values were seen for the general smile attractiveness (SA) and GS. Conclusion: the visual perception can be trained by changing the lip architecture and vertical leveling of the teeth and is influenced by gingival scalloping. This test proved to be useful in verifying the smile attractiveness.