A comparative study of the use of digital technology in the anterior smile experience.

OBJECTIVES: this study aims to compare the clinical outcomes of traditional and digital crown extension guides in the aesthetic restoration of anterior teeth. Additionally, the study will analyze the differences in the results of various digital crown extension guides in anterior aesthetic restorations. METHODS: Sixty-two patients who required aesthetic restoration of their anterior teeth were selected for this study. The patients had a total of 230 anterior teeth and were randomly divided into three groups: a control group of 22 cases who received diagnostic wax-up with pressure film, an experimental group 1 of 20 cases who received 3D printed digital models with pressure film, and an experimental group 2 of 20 patients who received digital dual-positioning guides. The control group had a total of 84 anterior teeth, experimental group 1 had 72 anterior teeth, and experimental group 2 had 74 anterior teeth. The study compared three methods for fabricating crown extension guides: the control group used the diagnostic wax-up plus compression film method, while experimental group 1 used compression film on 3D printed models and experimental group 2 used 3D printed digital dual-positioning crown extension guides. After the crown lengthening surgery, the control group patients wore DMG resin temporary crown material for gingival contouring, while the experimental group patients wore 3D printed resin temporary crowns for the same purpose. The patients were followed up in the outpatient clinic after wearing temporary crowns for 1 month, 3 months, and 6 months, respectively. The clinical results were evaluated in terms of marginal fit, red aesthetic index, and white aesthetic index. RESULTS: Based on the statistical analysis, the experimental group required significantly fewer follow-up visits and less time for guide design and fabrication compared to the control group. Additionally, the surgical time for the experimental group was significantly shorter than that of the control group. During the postoperative period between the 1st and 3rd month, the PES index scores for the marginal gingival level, proximal, and distal mesiodistal gingival papillae of the experimental group showed a trend of superiority over those of the control group. By the 6th month, the marginal gingival level exhibited a significant difference between the experimental and control groups. The experimental group demonstrated superior results to the control group in terms of shape, contour, and volume of the teeth, color, surface texture, and transparency of the restorations, and features during the 1st and 3rd postoperative months. In the 6th month, the comparative results indicated that the experimental group continued to exhibit superior outcomes to the control group in terms of the shape, color, surface texture, and transparency of the restorations, as well as the characteristics of the teeth. Additionally, the experimental group demonstrated significantly fewer gingival alterations than the control group at 1 month, 3 months, and 6 months post-procedure, with this difference being statistically significant. Furthermore, the combination of 3D printing technology and restorative techniques was utilized, resulting in consistent patient satisfaction. CONCLUSION: Digitalisation plays an important role in anterior aesthetic restorations. The use of digital technology to manage the entire process of anterior cosmetic restorations can improve restorative results, reduce the number of follow-up appointments, shorten consultation time, and achieve better patient satisfaction.

Reading of ingroup politicians' smiles triggers smiling in the corner of one's eyes.

Spontaneous smiles in response to politicians can serve as an implicit barometer for gauging electorate preferences. However, it is unclear whether a subtle Duchenne smile-an authentic expression involving the coactivation of the zygomaticus major (ZM) and orbicularis oculi (OO) muscles-would be elicited while reading about a favored politician smiling, indicating a more positive disposition and political endorsement. From an embodied simulation perspective, we investigated whether written descriptions of a politician's smile would trigger morphologically different smiles in readers depending on shared or opposing political orientation. In a controlled reading task in the laboratory, participants were presented with subject-verb phrases describing left and right-wing politicians smiling or frowning. Concurrently, their facial muscular reactions were measured via electromyography (EMG) recording at three facial muscles: the ZM and OO, coactive during Duchenne smiles, and the corrugator supercilii (CS) involved in frowning. We found that participants responded with a Duchenne smile detected at the ZM and OO facial muscles when exposed to portrayals of smiling politicians of same political orientation and reported more positive emotions towards these latter. In contrast, when reading about outgroup politicians smiling, there was a weaker activation of the ZM muscle and no activation of the OO muscle, suggesting a weak non-Duchenne smile, while emotions reported towards outgroup politicians were significantly more negative. Also, a more enhanced frown response in the CS was found for ingroup compared to outgroup politicians' frown expressions. Present findings suggest that a politician's smile may go a long way to influence electorates through both non-verbal and verbal pathways. They add another layer to our understanding of how language and social information shape embodied effects in a highly nuanced manner. Implications for verbal communication in the political context are discussed.

Determining the widths of the maxillary anterior teeth for esthetics: comparison of the Mondelli and Albers formulas, esthetic proportion, and golden ratio.

The purpose of this study was to compare various formulas for idealized proportions of the maxillary incisors to the actual dimensions of natural teeth. The Mondelli formula 1 (MF1), Mondelli formula 2 (MF2), Albers formula (AF), esthetic proportion (EP) for width and height of anterior teeth, and golden ratio (GR) were calculated for a total of 50 dental students (30 women and 20 men) who participated in the study. The following measurements were obtained directly in the participant's mouth with a digital caliper: the mesiodistal and incisogingival dimensions of the maxillary central incisors, lateral incisors, and canines; the intercanine distance; and the smile width. The participants were photographed, and the smile width was also measured on the photographs. The MF1 and MF2 were each calculated twice, using both direct measurements and photographic measurements. The projected central incisor widths calculated using the MF1, MF2, and AF were compared among themselves and against the actual measurements using analysis of variance and Fisher test for multiple comparisons (α = 0.05). The EP and GR were analyzed using descriptive statistics. There was a statistically significant difference between all of the widths projected by the formulas and the actual widths of the central incisors (P < 0.05). Whether calculated from a direct or a photographic measurement, the incisor widths projected by the MF1 and MF2 were statistically similar to each other (P > 0.05). The EP values were similar to those reported in the literature. Only 2% of the participants had an incisor width ratio (central incisor/lateral incisor) that matched the GR of 1.618, while 86% fell within the range of 1.2 to 1.4. Overall, the proportions calculated with the MF1, MF2, AF, EP, and GR did not exactly match the actual dimensions of natural teeth. The formulas and the proportions available in the literature can assist in esthetic planning, but the individual characteristics of each patient and expertise of the dentist should guide treatment for each case.

Asociación entre el biotipo facial y la posición del labio superior en la sonrisa / Association between facial biotype and the position of upper lip of the smile

Introducción: Para obtener una sonrisa ideal, es necesario que todas sus partes estén en armonía, mediante un equilibrio neurológico, muscular y esquelético. Así pues, la elaboración de un análisis facial y de sonrisa en el diagnóstico de ortodoncia, resulta de vital importancia, ya que la estética dental está muy relacionada conel tipo de sonrisa y el biotipo facial. Objetivo: determinar si existe asociación entre el biotipo facial y la posición del labio superior en la sonrisa. Material y métodos: el estudio es de tipo descriptivo, transversal y observacional. El universo de estudio fueron 1200 casos de la base de datos de la clínica de Posgrado de la Universidad Autónoma de Nayarit, México del año 2013 al 2023. La muestra fue de 120 pacientes pretratamiento de ortodoncia, analizando en ellos el biotipo facial y la altura de la línea de sonrisa. Se realizó la estadística descriptiva, pruebas de chi-cuadrado y V de Cramer. Resultados: el 34% presentó un biotipo braquifacial, el 31% dolicofacial y un 35% mesofacial. Se encontró en mayor porcentaje una línea de la sonrisa alta. En los pacientes dolicofaciales y mesofaciales la línea de sonrisa fue alta y en los pacientes braquifaciales fue media. La asociación entre el biotipo facial y la línea de sonrisa fue grande. Conclusiones: existe asociación entre el biotipo facial y la línea de sonrisa por lo que al realizar el diagnóstico en ortodoncia debe ser un factor a considerar. (AU)

Introduction: To obtain an ideal smile, it is necessary that all its parts are in harmony, through neurological, muscular and skeletal balance. Therefore, carrying out a facial and smile analysis in orthodontic diagnosis is of vital importance, since dental aesthetics is closely related to the type of smile, and the facial biotype. Objective: Determine if there is an association between facial biotype and the position of the upper lip in the smile. Material and Methods: The study is descriptive, cross-sectional and observational. The study was made of 1,200 cases from the database of the Postgraduate clinic of the Universidad Autónoma de Nayarit, Mexico from 2013 to 2023. The sample was 120 orthodontic pretreatment patients, analyzing their facial biotype and the height of the smile line. Descriptive statistics, chi square and Cramer’s V tests were performed. Results: 34% presented a brachyfacial biotype, 31% dolichofacial and 35% mesofacial. A high smile line was found in a higher percentage. In the dolichofacial and mesofacial patients the smile line was high and in the brachyfacial patients it was medium. The association between facial biotype and smile line was big. Conclusions: There is an association between the facial biotype and the smile line, so when making the orthodontic diagnosis it should be a factor to consider. (AU)

Creating an Extraordinary Outcome With Ordinary Digital Planning.

A patient was dissatisfied with her previous extensive dental treatment and wanted a comfortable bite with less gingival display for a more attractive smile. This article describes a systematic approach that was used in diagnosis, planning, and treatment sequencing to effectively manage the esthetic, functional, and biomechanical concerns involved in the case while minimizing risks. Digital planning enhanced interdisciplinary communication making the outcome more efficient and predictable.

Relationships between perception of black triangles appearance, personality factors and level of education.

This analytical cross-sectional study evaluated the perception of black triangles (BT) and examined the relationships between the perception of BT, personality factors, different educational backgrounds and demographic factors. 435 participants were included and divided into four groups: dentists, clinical (4th and 5th year) dental students, pre-clinical (3rd year) dental students, and laypeople. Participants' perception of the attractiveness of smile profiles of maxillary and mandibular anterior dentition with BT was rated using a ten-point VAS scale with 0 being the least, and 10 being the most attractive smile profile. The personality was assessed using the NEO-FFI personality questionnaire. The smile profile with multiple large BT was rated the least attractive for the maxillary (mean = 3.6) and mandibular (mean = 3.9) tested profiles. The smile profile without BT was rated the most attractive for the maxillary (mean = 9.1) and mandibular (mean = 8.8) tested profiles. The dental professionals perceived the maxillary smile profile with multiple large BT as less attractive than the non-dental participants (t = - 2.715, P = 0.007). Being a male, having dental education, having lower Neuroticism scores, as well as having higher Openness, Agreeableness, Conscientiousness, and Extraversion scores predicted and contributed more towards perceiving various tested smile profiles as more attractive. These findings show that black triangles negatively impacts the perception of smile attractiveness, and that personality traits and having dental education impact the perception of smile attractiveness for smiles with black triangles.

Influence of education level and gender of dental students on perception of dental aesthetics.

BACKGROUND: Fulfilling aesthetic norms is an imperative of modern society. Accordingly, aesthetics has found its important role in dental medicine. The aim was to study whether there is a difference in the perception of tooth shade change and anatomical variations of anterior maxillary teeth among dental students depending on the level of education, gender, and experience in assisting in a dental office. METHODS: The research was conducted among dental students via the Google Forms platform. Students evaluated the aesthetic acceptability of a smile on the unaltered, reference photograph (RP) and on the other 28 photographs in which the tooth shade (lighter and darker teeth), length (shortened central incisors, elongated, and beveled lateral incisors, elongated canines) and position (atypical and typical rotations and diastemas) of the upper maxillary teeth were altered by digital manipulation. The 1-10 assessment scale was used. Statistical analysis comprised one-way Kolmogorov-Smirnov test, X2 tests, t-test, and 3-way MANOVA. RESULTS: In the research 208 students participated, 113 were preclinical students, 104 assisted in dental office and 175 were females. There were no significant effects of gender regarding length and position modifications (p > .05), while women were stricter in evaluation of lighter shade (p < .05). Clinical students were stricter in evaluating all manipulated photographs (MP) except those towards darker shade modifications, while assisting in a dental office or having a dentist in close family showed no significant effects (p > .05). CONCLUSIONS: With a higher level of targeted academic education, dental students sharpen their ability to notice deviations from the aesthetic norms of a smile.

Aesthetic treatment planning simplified using digital smile design: A case report.

Digital smile design (DSD) plays an essential role in the planning of aesthetic treatments. However, most digital smile designing software programmes are expensive and require specialised training and skill for effective implementation. This paper illustrates the use of Adobe Photoshop and Microsoft PowerPoint, which are economical and user friendly for planning aesthetics in a clinical case.

Smile aesthetics in Pakistani population: dentist preferences and perceptions of anterior teeth proportion and harmony.

BACKGROUND: This study aimed to evaluate dentist perceptions of attractive smiles in the Pakistani population, considering different dental proportions. METHODS: Maxillary casts and digital images were used to create symmetrical representations of anterior teeth. dentists' preferences for good and bad teeth proportions, width/height ratios, and various dental proportions (golden, recurring esthetic dental (RED), golden percentage, Preston, and local/observed) were assessed using one sample and paired t-test. The Chi-square test was used to determine the gender disparities and factors affecting smile attractiveness. A p-value of ≤ 0.05 was taken as significant. RESULTS: The RED proportion emerged as the preferred choice for normal-sized teeth, with specialists and general dentists favoring it over the golden proportion. For tall teeth, the golden proportion was predominantly preferred. The golden percentage received limited preference for aesthetic smile construction. CONCLUSIONS: The smiles created using the principles of RED proportion were opted as the most attractive by local dentists. Factors such as tooth arrangement, color, and midline were highlighted as essential considerations in aesthetic smile construction.

The association between self-esteem and aesthetic component of smile among adolescents.

OBJECTIVES: Self-esteem plays a crucial role during adolescence in a shaping of an individual's overall well-being and confidence. The aim of this study was to explore the relationship between the self-esteem in adolescents and their smile aesthetics, as well as to assess the alignment of opinions on this matter between adolescents and dentists. METHODS: Sample included 413 students in Split-Dalmatia County, aged 13 to 18 (60% females). Data on demographic issues, orthodontic history, and desire for orthodontic treatment were collected by the self-administrated questionnaire. Coopersmith's Self-Esteem Inventory was also used. Smile aesthetics was assessed by each participant and dentist independently using an Aesthetic Component of the Index of Orthodontic Treatment Need (IOTN AC). RESULTS: Self-esteem was higher in adolescents who rated their smile aesthetics equally to the dentist than in those who considered their aesthetics to be worse than the dentist (18.5 vs. 16; P = 0.011). The multiple linear regression revealed that the self-esteem of adolescents was positively related to undergone previous orthodontic treatment (ß = 1.286, P = 0.020) while negatively related to the female gender (ß = -2.531, P ≤ 0.001) and IOTN AC assessed by dentist (ß = -0.356, P = 0.015). It was not related to educational level or desire for orthodontic treatment. CONCLUSION: The self-esteem in adolescence is influenced the most by gender, but the orthodontic treatment and better smile aesthetics might also contribute.

A deepfake-based study on facial expressiveness and social outcomes.

Artificial intelligence (AI)-generated media is used in entertainment, art, education, and marketing. AI-generated faces or facial expressions using deepfake-based technologies might also contribute to nonverbal behavior studies. As a proof of concept, in this research, we test the replicability of past results regarding the positive effects of facial expressiveness (e.g., gazing, nodding, and smiling) on social outcomes. Because the facial expressions when listening to someone (i.e., nonverbal immediacy) encompass several behaviors that are typically related (i.e., smiling while nodding), the effect of combinations of these behaviors is challenging to study. We thus test the effect of facial expressiveness (gazing, nodding, and smiling vs. none) on first impression judgements in a job interview setting using AI-generated experimental video material. We measure how competent, warm, and favorably independent observers (n = 823) perceive the targets (n = 159) showing AI-generated facial expressions. Our results replicate past research showing that the more targets are facially expressive, the more they are perceived favorably. Apart from supporting evidence of the importance of facial expressiveness for conveying a positive impression, we show the benefits of relying on AI-generated experimental video material for the study of nonverbal behavior.

Can group membership modulate the social abilities of autistic people? An intergroup bias in smile perception.

Autistic adults struggle to reliably differentiate genuine and posed smiles. Intergroup bias is a promising factor that may modulate smile discrimination performance, which has been shown in neurotypical adults, and which could highlight ways to make social interactions easier. However, it is not clear whether this bias also exists in autistic people. Thus, the current study aimed to investigate this in autism using a minimal group paradigm. Seventy-five autistic and sixty-one non-autistic adults viewed videos of people making genuine or posed smiles and were informed (falsely) that some of the actors were from an in-group and others were from an out-group. The ability to identify smile authenticity of in-group and out-group members and group identification were assessed. Our results revealed that both groups seemed equally susceptible to ingroup favouritism, rating ingroup members as more genuine, but autistic adults also generally rated smiles as less genuine and were less likely to identify with ingroup members. Autistic adults showed reduced sensitivity to the different smile types but the absence of an intergroup bias in smile discrimination in both groups seems to indicate that membership can only modulate social judgements but not social abilities. These findings suggest a reconsideration of past findings that might have misrepresented the social judgements of autistic people through introducing an outgroup disadvantage, but also a need for tailored support for autistic social differences that emphasizes similarity and inclusion between diverse people.

A Case Series of Isolated Smiling Tremor: What Is the Phenomenology?

BACKGROUND: Five cases of tremor only upon smiling have been reported where no facial tremor is present at rest, when talking, or with full smile. CASES: This report highlights four cases of tremor upon partial smiling, discusses the phenomenology of smiling tremor, and reviews the current literature. Four subjects with lower facial tremor present only upon smiling underwent movement disorders evaluation with video. Tremor frequencies were determined by parsing the video clips into 1-second intervals and averaging the number of oscillations per interval and were determined to be high-frequency 8 to 10 Hz irregular facial tremors with harmonic variations upon moderate effort in all cases. Slight or full-effort smiling did not elicit facial muscle oscillations. Subjects had no other signs of tremor, dystonia, or parkinsonism on examination or in family history. CONCLUSIONS: Tremor upon smiling only, or isolated smiling tremor, is a unique task- and position-specific tremor of the facial musculature.

Unveiling why race does not affect the mask effect on attractiveness: but gender and expression do.

Studies show that surgical face masks can have both positive and negative effects on attractiveness. Race has been implicated as a moderator of the size of this mask effect. Here, the moderating effects of expression, race and gender are explored. The mask effect was more positive for males than for females, for neutral faces than for smiling faces, and there were differences between the races. Further, the effect of unmasked attractiveness was partialled out for each image, which removed the race effects, but the gender and expression effects remained. It is suggested that racial differences previously observed in the mask effects are a consequence of differences in attractiveness of the faces sampled from those races. Re-analysis of previous research that showed race effects also demonstrates how they are better explained as attractiveness effects rather than race effects. This explanation can provide order to the different findings observed across the literature.

What is in a smile: The role of evaluation goal and response labels in facial muscle responses to prejudiced groups.

Based on the assumption that valence is permanently linked to facial responses, we expected that the corrugator muscle is contracted faster in response to overweight persons than to slim persons, whereas we expected faster contractions of the zygomaticus muscle in response to slim persons rather than to overweight persons. To detect such differences, we conducted experiments with different versions of a facial stimulus-response compatibility task that required participants to respond with the two facial muscles to photos of overweight or slim persons. Contrary to the assumption that valence is permanently linked to facial responses, in Experiments 1 and 2, social categories (overweight vs. slim persons) did not influence the response latencies assessed by electromyography. Whereas in Experiments 1 and 2, neutral labels were used for the muscle responses, in Experiment 3, affective response labels (smile vs. frown) were used. In Experiment 3, faster responses with the corrugator to overweight than to slim persons and with the zygomaticus to slim than to overweight persons were obtained. The influence of task and response label is consistent with the theory of event coding that suggests a more flexible link between valence and action.

Evaluation of the impact of orthodontists' smile with malocclusions on social media and professional credibility.

OBJECTIVES: This study assessed laypeople's perceptions of orthodontist credibility based on malocclusions and whether these views affect their choice to seek treatment. Eye-tracking technology and questionnaires were utilized. MATERIALS AND METHODS: Ninety-five lay raters, through eye tracking and a questionnaire, assessed 12 images of orthodontists with malocclusions. Malocclusions were categorized by the Index Of Treatment Need (IOTN) as grade 1 (near ideal), 3 (anterior crowding), and 5 (with diastemas). Fixation points were recorded, and credibility was gauged via questionnaires. A Mentimeter word cloud was generated. RESULTS: IOTN 1 orthodontists were viewed as more credible than IOTN 3 (p < 0.001) and 5 (p < 0.001). Raters were more willing to receive treatment from IOTN 1 orthodontists. The focus for IOTN 1 was between eyes and mouth, while IOTN 3 and 5 were on the mouth. "Crooked teeth" and "spacing" were predominant in word clouds for IOTN 3 and 5. CONCLUSION: Orthodontists with an IOTN grade 1 rating were perceived as more competent, reliable, and professional, thus making it more likely for laypeople to choose them as their preferred providers. CLINICAL RELEVANCE: The smiles of professionals play a significant role in laypeople's decision to choose them as their orthodontist, and strategic utilization of social media can effectively deliver health information to a larger audience in a faster and more direct manner.

High depressive symptomatology reduces emotional reactions to pictures of social interaction.

Individuals with severe depressive symptoms present diminished facial expressions compared to healthy individuals. This reduced facial expression, which occurs in most depressive patients could impair social relationships. The current study sought to investigate whether pictures with social interaction cues could elicit different modulations of facial expressions and mood states in individuals with depressive symptoms compared to healthy individuals. A total of 85 individuals were divided into depressive and non-depressive groups based on their beck depression inventory scores. Participants viewed pictures containing neutral (objects), affiliative (people interacting socially), and control (people not interacting) scenes. Electromyographic signals were collected during the entire period of visualization of the blocks, and emotional questionnaires were evaluated after each block to assess sociability and altruism (prosocial states). In non-depressed individuals, affiliative pictures increased the activity of the zygomatic muscle compared to both neutral and control pictures and reduced fear of rejection compared to neutral pictures. During the visualization of the affiliative block, zygomatic major muscle activation was higher and fear of rejection was lower in the non-depressive individuals than in the depressive. These effects reflected the low expressions of smiling and sociability to affiliative pictures in depressive individuals. These findings highlight the importance of smiling and prosocial states in social interactions, especially in these individuals.