Perception of dental appearance and aesthetic analysis among patients, laypersons and dentists

BACKGROUND

Current concepts of beauty are increasingly subjective, influenced by the viewpoints of others. The aim of the study was to evaluate divergences in the perception of dental appearance and smile esthetics among patients, laypersons and dental practitioners. The study goals were to evaluate the influence of age, sex, education and dental specialty on the participants' judgment and to identify the values of different esthetic criteria. Patients sample included 50 patients who responded to a dental appearance questionnaire (DAQ). Two frontal photographs were taken, one during a smile and one with retracted lips. Laypersons and dentists were asked to evaluate both photographs using a Linear Scale from (0-10), where 0 represent (absolutely unaesthetic) and 10 represent (absolutely aesthetic). One-way analysis of variance (ANOVA) and t-test analysis were measured for each group. Most patients in the sample expressed satisfaction with most aspects of their smiles and dental appearance. Among laypersons (including 488 participants), 47 pictures "with lips" out of 50 had higher mean aesthetic scores compared to pictures "without lips". Among the dentist sample, 90 dentists' perception towards the esthetic smile and dental appearance for photos "with lips" and "without lips" were the same for 23 out of 50 patients. Perception of smile aesthetics differed between patients, laypersons and dentists. Several factors can contribute to shape the perception of smile aesthetic.

AIM

To compare the perception of dental aesthetic among patients, laypersons, and professional dentists, to evaluate the impact of age, sex, educational background, and income on the judgments made by laypersons, to assess the variations in experience, specialty, age, and sex on professional dentists' judgment, and to evaluate the role of lips, skin shade and tooth shade in different participants' judgments.

METHODS

Patients sample included 50 patients who responded to DAQ. Two frontal photographs were taken: one during a smile and one with retracted lips. Laypersons and dentists were asked to evaluate both photographs using a Linear Scale from (0-10), where 0 represent (absolutely unaesthetic) and 10 represent (absolutely aesthetic). One-way ANOVA and t-test analysis were measured for each group.

RESULTS

Most patients in the sample expressed satisfaction with most aspects of their smiles and dental appearance. Among laypersons (including 488 participants), 47 pictures "with lips" out of 50 had higher mean aesthetic scores compared to pictures "without lips". Whereas among the dentist sample, 90 dentists' perception towards the esthetic smile and dental appearance for photos "with lips" and "without lips" were the same for 23 out of 50 patients. Perception of smile aesthetics differed between patients, laypersons and dentists.

CONCLUSION

Several factors can contribute to shape the perception of smile aesthetic.

Automated reconstruction: Predictive models based on facial morphology matrices

Forensic Facial Approximation (FFA) has evolved, with techniques advancing to refine the intercorrelation between the soft-tissue facial profile and the underlying skull. FFA has become essential for identifying unknown persons in South Africa, where the high number of migrant and illegal labourers and many unidentified remains make the identification process challenging. However, existing FFA methods are based on American or European standards, rendering them inapplicable in a South African context. We addressed this issue by conducting a study to create prediction models based on the relationships between facial morphology and known factors, such as population affinity, sex, and age, in white South African and French samples. We retrospectively collected 184 adult cone beam computed tomography (CBCT) scans representing 76 white South Africans (29 males and 47 females) and 108 French nationals (54 males and 54 females) to develop predictive statistical models using a projection onto latent structures regression algorithm (PLSR). On training and untrained datasets, the accuracy of the estimated soft-tissue shape of the ears, eyes, nose, and mouth was measured using metric deviations. The predictive models were optimized by integrating additional variables such as sex and age. Based on trained data, the prediction errors for the ears, eyes, nose, and mouth ranged between 1.6 mm and 4.1 mm for white South Africans; for the French group, they ranged between 1.9 mm and 4.2 mm. Prediction errors on non-trained data ranged between 1.6 mm and 4.3 mm for white South Africans, whereas prediction errors ranging between 1.8 mm and 4.3 mm were observed for the French. Ultimately, our study provided promising predictive models. Although the statistical models can be improved, the inherent variability among individuals restricts the accuracy of FFA. The predictive validity of the models was improved by including sex and age variables and considering population affinity. By integrating these factors, more customized and accurate predictive models can be developed, ultimately strengthening the effectiveness of forensic analysis in the South African region.

Lexical tone perception and learning in older adults: A review and future directions

While the literature is well represented in accounting for how aging influences segmental properties of speech, less is known about its influences on suprasegmental properties such as lexical tones. In addition, foreign language learning is increasingly endorsed as being a potential intervention to boost cognitive reserve and overall well-being in older adults. Empirical studies on young learners learning lexical tones are aplenty in comparison with older learners. Challenges in this domain for older learners might be different due to aging and other learner-internal factors. This review consolidates behavioural and neuroscientific research related to lexical tone, speech perception, factors characterising learner groups, and other variables that would influence lexical tone perception and learning in older adults. Factors commonly identified to influence tone learning in younger adult populations, such as musical experience, language background, and motivation in learning a new language, are discussed in relation to older learner groups and recommendations to boost lexical tone learning in older age are provided based on existing studies.

Influence of gingival display on smile attractiveness assessed by Saudi Arabian laypersons and dental professionals

This study was undertaken to evaluate the influence of changes in the gingival display of the maxillary teeth on smile attractiveness assessed by Saudi Arabian dental professionals and laypeople. A total of 138 dental professional and 182 laypeople rated the attractiveness of male and female smiles in a computerized survey. A smiling photograph of a male and a female dental students were selected and digitally manipulated to create changes the amount of gingival display from 4 mm of gingival display to 4mm of gingival covered by the upper lip in 1 mm increments. Each photo was accompanied by a visual analog scale (VAS) for rating. Among dental professionals, 61% rated the female photo with a 1-mm low lip line as the most attractive smile (VAS score ± SE, 7.3 ± 3.18), while 52.7% of laypeople considered the smile with a 2-mm low lip line as the most attractive (6.7 ± 3.4). Regarding male smile photos, 61.6% of dental professionals found the 1-mm low lip line the most attractive (7.3 ± 3.18). The same rating was given by 48.3% of laypeople (6.1 ± 3.6) (p ≤ 0.009). The least attractive smile photo was the smile showing 4 mm of gingiva for male and female smiles. More than half of the laypeople believed that an attractive smile highly affects social life and communication. The Saudi Arabian population appears to be sensitive to the amount of gingival display. The difference in female smile assessment between dental professionals and laypeople highlights the importance of dentist-patient consensus regarding decisions for esthetic treatments. Esthetic treatment is of a major concern for both dentist and patient. The careful assessment of smile pillars including gingival display must be tailored to each patient.

The effect of orthodontic treatment on smile attractiveness: a systematic review

BACKGROUND

Smile attractiveness is a primary factor for patients to seek orthodontic treatment, however, there is yet no systematic evaluation of this topic in the literature.

OBJECTIVES

To assess the current evidence on the effect of orthodontic treatment on smile attractiveness.

SEARCH METHODS

Seven electronic databases (MEDLINE, Cochrane Library, Virtual Health Library, SCOPUS, Web of Science, Google Scholar and Embase) were searched on 14 September 2022.

SELECTION CRITERIA

Studies evaluating smile attractiveness before and after orthodontic treatment or only after completion of orthodontic treatment.

DATA COLLECTION AND ANALYSIS

Extracted data included study design and setting, sample size and demographics, malocclusion type, treatment modality and method for outcome assessment. Risk of bias was assessed with the ROBINS-I tool for non-randomised studies. Random-effects meta-analyses of mean differences and their 95% confidence intervals (CIs) were planned a priori.

METHODS

After elimination of duplicate studies, data extraction and risk of bias assessment according to the Cochrane guidelines, an evaluation of the overall evidence was performed. The included studies were evaluated based on the characteristics of their study and control groups and based on their main research question. Also, all outcome measures were standardized into a common assessment scale (0-100), in order to obtain more easily interpretable results.

RESULTS

Ten studies were included in this review, nine of which were assessed as being at serious risk of bias and one at moderate risk of bias. The large heterogeneity between the included studies did not allow for a meta-analysis. Orthodontic treatment has a moderately positive effect on smile attractiveness. When compared to no treatment, orthodontic treatment with premolar extractions improves smile attractiveness by 22%. Also, surgical correction of Class III cases increases smile attractiveness by 7.5% more than camouflage treatment. No other significant differences were shown between different types of treatment.

CONCLUSION

Based on the available data, orthodontic treatment seems to moderately improve the attractiveness of the smile. There is significant bias in the current literature assessing the effect of orthodontics on smile attractiveness; therefore, the results cannot be accepted with certainty.

The perception of smile attractiveness to altered vertical position of maxillary anteriors by various groups

There is a gap in research about the differences in smile attractiveness. The problem the study addresses is how the vertical canine and incisor position affect smile attractiveness. The aim of this study was to assess the perception of the smile attractiveness between Saudi laypersons, orthodontists, non-orthodontist, and various dental students levels, and to determine how the canine and incisor vertical positions affect the attractiveness of smile. The study is a cross-sectional survey and was conducted at King Abdulaziz University, Jeddah, Saudi Arabia. Six groups of subjects participated in the study: Orthodontic residents (n = 31), prosthodontic, restorative, periodontics specialties residents specialties residents (n = 30), interns (n = 31), fifth year students (n = 41), 6th year students (n = 39), and laypeople (n = 39). Participants were asked to rate the attractiveness of a smile of a female subject photographed using a Minolta DiMage 7i digital camera. The image had been manipulated to produce 2 sets of images; 1 to modify the incisors and 1 to change the canines. The subjects were asked to choose the most and least attractive picture. For the best incisor positions, only the laypeople and prosthodontics liked the original picture, the rest liked +0.5 mm which accentuate the smile curve and make it follow the lower lip line. For the worst incisor position, all groups did not prefer the minus 1.5 reversed smile. For the best canine vertical position, all groups preferred the original position where canine was at the level of the incisal plane. For the worst canine position, they all disliked the minus 1.5 reversed smile. Results confirmed past findings that orthodontists are in general more critical about smile attractiveness than laypersons, but just like other dental specialists. The findings can be used in the esthetic dentistry field, but further research on the study population based on other dental design parameters remain necessary.

Neuropsychological correlates of evocative multimodal speech: The combined roles of fearful prosody, visuospatial attention, cortisol response, and anxiety

Past research reveals left-hemisphere dominance for linguistic processing and right-hemisphere dominance for emotional prosody processing during auditory language comprehension, a pattern also found in visuospatial attention studies where listeners are presented with a view of the talker's face. Is this lateralization pattern for visuospatial attention and language processing upheld when listeners are experiencing a stress response? To investigate this question, participants completed the Trier Social Stress Test (TSST) between administrations of a visuospatial attention and language comprehension dual-task paradigm. Subjective anxiety, cardiovascular, and saliva cortisol measures were taken before and after the TSST. Higher language comprehension scores in the post-TSST neutral prosody condition were associated with lower cortisol responses, differences in blood pressure, and less subjective anxiety. In this challenging task, visuospatial attention was most focused at the mouth region, both prior to and after stress induction. Greater visuospatial attention on the left side of the face image, compared to the right side, indicated greater right hemisphere activation. In the Fear, but not the Neutral, prosody condition, greater cortisol response was associated with greater visuospatial attention to the left side of the face image. Results are placed into theoretical context, and can be applied to situations where stressed listeners must interpret emotionally evocative language.

Contribution of facial components to the attractiveness of the smiling face in male and female patients: A cross-sectional correlation study

INTRODUCTION

Esthetic improvement is a key motivator in undergoing orthodontic treatment. This study aims to quantify the contribution of the smile and other facial components to the overall esthetics of attractiveness.

METHODS

The attractiveness of 60 subjects (30 men, 30 women), aged 18-35 years, before orthodontic treatment, was retrospectively evaluated by 8 laypersons using the Visual Analog Scale. Pearson and stepwise correlations were calculated between the attractiveness of the smiling face and the attractiveness of facial components; namely the smile, nose, eyes, hair, chin, eyebrows, and skin.

RESULTS

A strong correlation between the face and smile attractiveness was found (r = 0.71) for the whole sample. No significant correlations were found between attractiveness and the other facial components. When divided by gender, the smile (r = 0.70) and the eyes (r = 0.51) correlated with the attractiveness of the smiling face for men. For women, the face registered a significant correlation with the smile (r = 0.83) and the skin (r = 0.37).

CONCLUSIONS

In general, smile attractiveness was strongly correlated with the attractiveness of the smiling face, which is the only significant component. For men, the smile was responsible for 49% of the variation in the attractiveness of the smiling face, the eyes for 22%, and the hair for 6%. For women, 69% of the variation in facial attractiveness could be attributed to smile.

Influence of orthodontic appliance design on employment hiring preferences

INTRODUCTION

The objective of this study was to evaluate the extent to which different types of orthodontic appliances influence the hiring process of an individual applying for a customer service position.

METHODS

A total of 7 images were created for 2 adult models: 1 male and 1 female. One image was produced without orthodontic appliances, and 6 simulated the use of orthodontic appliances, including a conventional metallic appliance with a gray elastic ligature, a conventional metallic appliance with blue elastic ligature, a conventional appliance with a transparent elastic ligature, a self-ligating metal appliance, a self-ligating esthetic appliance, and a clear aligner. A photo album was designed for each model and delivered, along with a questionnaire, to individuals in charge of job interviews and hiring. These evaluators included 236 individuals, divided into 4 groups according to age and gender: males between 18-35 years (M), males over 35 years (M > 35), females between 18-35 years (F), and females over 35 years (F > 35). The evaluators quantified the chance of hiring the models using a Visual Analogue Scale. The Mann-Whitney test was used to compare the evaluators according to gender and age. The Wilcoxon test was used to compare the models according to gender. The Kruskal-Wallis and Dunn post hoc tests were used to compare the appliances according to design. A 5% significance level was used for all tests.

RESULTS

The clear aligner group showed the highest likelihood of being hired, followed by the group without orthodontic appliances, the groups with esthetic appliances (ie, conventional appliance with a transparent elastic ligature, and self-ligating esthetic appliance), and the groups with metallic appliances (ie, self-ligating metal appliance, conventional metallic appliance with gray elastic ligature, and conventional metallic appliance with blue elastic ligature).

CONCLUSIONS

Assuming all other qualifications of the applicants are equivalent, the use of an orthodontic appliance may influence job interviews. The better the esthetics of the appliance, the higher the likelihood of the individual being hired.

Layperson's preference of the transverse occlusal plane in asymmetric facial model

OBJECTIVE

Facial asymmetries are common, especially deviated nose and chin. The clinician must consider these variables when establishing the smile, placement and angulation of the occlusal plane. The purpose of this article is to determine if nose and chin deviations affect the perception of laypeople towards different angulations of the occlusal plane cant.

MATERIALS AND METHOD

An asymmetric facial model was created from a symmetric facial model used in a previous study. Nose and chin were deviated 3 mm to the left and eight different pictures were created, each with different degrees of occlusal plane cant in both direction. Using a visual Likert scale delivered via Websurvey within the private practice setting, 120 randomly selected laypersons evaluated each image according to their own beauty preferences.

RESULTS

In an asymmetric face, nose and chin deviated 3 mm to the left, a minor occlusal plane angulation of 2° can be perceptible regardless of the direction of the cant.

CONCLUSIONS

The occlusal plane should be as parallel to the interpupillary line as possible. If occlusal cant is present, less than 2° of angulation it is preferable, regardless of the direction of the nose and chin.

CLINICAL SIGNIFICANCE

In the presence of an asymmetric face, the occlusal plane should be as parallel as possible to the interpupillary line. The direction of the deviation of the nose and the chin are irrelevant factors to determine the occlusal plane. An inclination of the occlusal plane can cause vertical discrepancy, which could subsequently create malocclusion. A complete dentofacial analysis can aim at assessing the angulation of the occlusal plane not only for esthetic outcomes, but for also allowing correct occlusal function.

Evaluation of preferred lip position according to different tip rotations of the nose in class I young adult subjects

INTRODUCTION

The mouth plays an important role in the overall aesthetic appearance of the face. The aims of this study were to determine the optimal antero-posterior (AP) lip position relative to various rotations of the nasal tip and assess the impact of the nasolabial angle on facial aesthetics.

MATERIAL AND METHODS

Three-dimensional facial volumes, in motion, of one Caucasian male and one Caucasian female with a Class I malocclusion and an orthognathic profile were modified to alter the nasal tip rotation (3 rotations) and the AP lips position (6 positions). 72 generated models were created in two and three-dimensions. Generated models were rated online by 60 dentists, 60 orthodontists and 60 laypeople, using a Visual Analogue Scale. Scores were analysed according to lip position, rater's profession and gender.

RESULTS

General agreement was found between all groups on the most and least preferred lip positions. No differences between male and female raters were found. All raters were more influenced by the 3-dimensional rotating facial volume than by 2-dimensional angles. Similar angular values for the nasolabial angles were found in the most and least preferred profiles, showing that the most influential factor in facial aesthetics was the lip position, and stressing the need to evaluate each component of the nasolabial angle independently.

CONCLUSION

The lip position was the determinant factor in facial aesthetics with little influence of the nose tip rotation. Three-dimensional evaluation of the nose and lip were needed to establish a soft tissue-based treatment plan.

Smile prevails over other facial components of male facial esthetics

BACKGROUND

The aim of this study was to assess whether scores assigned to the eyes, nose, mouth, and chin regions work as predictors of full smiling face scores.

METHODS

In this cross-sectional study, the authors used the facial photographs of 86 smiling men. Photographs yielded 5 components: 1 of the face itself and 4 subcomponents (eyes, nose, mouth, and chin region). Raters assigned the photographs beauty scores that the authors measured morphometrically. The authors analyzed the predictive ability of the subcomponents against that of the full face.

RESULTS

The subcomponents were statistically significant predictors of facial beauty (mouth: r² = 0.38, P < .0001; eyes: r² = 0.14, P < .0001; chin region: r² = 0.09, P < .0001; nose: r² = 0.02, P = .05). The more beautiful people had several statistically significant characteristics, such as narrower faces.

CONCLUSIONS

Facial subcomponents are predictive factors of the male smiling face and contribute in the following descending order of importance: mouth, eyes, chin region, and nose.

PRACTICAL IMPLICATIONS

The results suggest that for many people improvement in smile esthetics also likely will exert a more positive effect on facial beauty than will other procedures (for example, rhinoplasty).

Personality Style in Patients Looking for Tooth Bleaching and Its Correlation with Treatment Satisfaction

In the last years the focus in dentistry has shifted to an "esthetic dentistry" approach, where patients are concerned about reaching a better look of their teeth. Vital tooth bleaching is a technique with immediate results, which improves the appearance and patient's self-esteem. The aim of this study was to recognize personality characteristics determined by the Millon Index of Personality Styles of participants looking for tooth bleaching and to correlate them to satisfaction with the treatment. Forty participants were included and filled out the Millon Index of Personality Styles form before treatment. Expectation about tooth bleaching was quantified from 1 to 5. Patients were treated with bleaching agent according to manufacturer's directions. One week after treatment, the patient's satisfaction was quantified from 1 to 5. Prevailing personality characteristics were determined. Expectations and satisfaction values of all patients were correlated with each of the presented personality scales by Spearman Rho test. Ten scales prevailed over their counterpart. Median of patient's expectation was 2 and satisfaction 4. Only the score of a single characteristic (extraversing) showed statistically significant correlation with patient satisfaction. Patients looking for tooth bleaching treatment seem to have common personality characteristics. Almost all of them wanted to achieve a moderate change in teeth color and the result of the treatment was usually satisfactory.

Practical Application of Anatomy of the Oral Cavity in Forensic Facial Reconstruction

The oral cavity's importance in defining the facial region makes it a primary feature for forensic facial reconstruction (FFR). The aim of this study is to construct a pattern of reference for dimensions and proportions of the lips and establish parameters that may help estimate the vermilion borders' height dimensions and the mouth's width. By means of cone beam computed tomography, divided into two samples: sample 1 (n = 322; 137 male, 185 female) verified the linear distances delimited by anatomical landmarks in soft tissue. The sample 2 (n = 108; 40 male, 68 female), verified the proportions among the height of the vermilion borders, width of the mouth, and linear distances between craniometric landmarks in hard tissues, both from a Brazilian database. The measurements were completed using OsiriX, and the results were analyzed by means of descriptive statistics at a level of significance of 5%. The height of the vermilion borders corresponded to approximately 26% of the width of the mouth. The width of the mouth increased over the course of time in men and remained stable in women. In men, a mean intercanine distance of 75% of the total mouth's width was found; for women, it was 80%. The parameters of the relations between soft and hard tissues in the oral cavity region presented that the distance between landmarks ID-SM (Infradentale-Supramentale) corresponded to 55% of the height of the vermilion borders of the mouth for both sexes, while the distance between landmarks PM-SD (Philtrum medium-Supradentale) corresponded to 85% in men and 88% in women. Mean values of 97% of the width of the mouth in women and 93% in men were attributed to the distance between the mentonian foramina. It was not possible to estimate the height of the labial vermilion borders by the bone measurements, FIs-Fli (Foramen incisivus superius-inferius) and NS-GN (Nasospinale-Gnathion). Profound knowledge of the anatomy and morphology of the oral cavity may contribute to increasing the precision of FFRs and help with human identification.

Lip movements entrain the observers' low-frequency brain oscillations to facilitate speech intelligibility

During continuous speech, lip movements provide visual temporal signals that facilitate speech processing. Here, using MEG we directly investigated how these visual signals interact with rhythmic brain activity in participants listening to and seeing the speaker. First, we investigated coherence between oscillatory brain activity and speaker’s lip movements and demonstrated significant entrainment in visual cortex. We then used partial coherence to remove contributions of the coherent auditory speech signal from the lip-brain coherence. Comparing this synchronization between different attention conditions revealed that attending visual speech enhances the coherence between activity in visual cortex and the speaker’s lips. Further, we identified a significant partial coherence between left motor cortex and lip movements and this partial coherence directly predicted comprehension accuracy. Our results emphasize the importance of visually entrained and attention-modulated rhythmic brain activity for the enhancement of audiovisual speech processing.

DOI:http://dx.doi.org/10.7554/eLife.14521.001

People are able communicate effectively with each other even in very noisy places where it is difficult to actually hear what others are saying. In a face-to-face conversation, people detect and respond to many physical cues – including body posture, facial expressions, head and eye movements and gestures – alongside the sound cues. Lip movements are particularly important and contain enough information to allow trained observers to understand speech even if they cannot hear the speech itself.

It is known that brain waves in listeners are synchronized with the rhythms in a speech, especially the syllables. This is thought to establish a channel for communication – similar to tuning a radio to a certain frequency to listen to a certain radio station. Park et al. studied if listeners’ brain waves also align to the speaker’s lip movements during continuous speech and if this is important for understanding the speech.

The experiments reveal that a part of the brain that processes visual information – called the visual cortex – produces brain waves that are synchronized to the rhythm of syllables in continuous speech. This synchronization was more precise in a complex situation where lip movements would be more important to understand speech. Park et al. also found that the area of the observer’s brain that controls the lips (the motor cortex) also produced brain waves that were synchronized to lip movements. Volunteers whose motor cortex was more synchronized to the lip movements understood speech better. This supports the idea that brain areas that are used for producing speech are also important for understanding speech.

Future challenges include understanding how synchronization of brain waves with the rhythms of speech helps us to understand speech, and how the brain waves produced by the visual and motor areas interact.

DOI:http://dx.doi.org/10.7554/eLife.14521.002

10 commandments of smile esthetics

The search for esthetic treatment has persisted in the routine of dental professionals. Following this trend, dental patients have sought treatment with the primary aim of improving smile esthetics. The aim of this article is to present a protocol to assess patient's smile: The 10 Commandments of smile esthetics.

The role of personality traits in self-rated oral health and preferences for different types of flawed smiles

Symmetric, aligned and luminous smiles are usually classified as 'beautiful' and aesthetic. However, smile perception is not strictly governed by standardised rules. Personal traits may influence the perception of non-ideal smiles. We aimed to determine the influence of personality traits in self-rated oral health and satisfaction and in the aesthetic preference for different strategically flawed smiles shown in photographs. Smiles with dark teeth, with uneven teeth, with lip asymmetry and dental asymmetry were ordered from 1 to 4 as a function of the degree of beauty by 548 participants, of which 50·7% were females with a mean age of 41·5 ± 17·6 years (range: 16-89 years). Self-assessment and oral satisfaction were recorded on a Likert scale. Personality was measured by means of the Big Five Inventory (extraversion, agreeableness, conscientiousness, neuroticism and openness), and the Life Orientation Test was used to measure optimism and pessimism. Of the four photographs with imperfect smiles, dental asymmetry was the most highly assessed in 63% of the sample, and the worst was lip asymmetry, in 43·7% of the sample. Some personality traits (above all conscientiousness and openness) were significantly correlated with the position assigned to the photographs with dental and lip asymmetry or with misaligned teeth. The extraversion, agreeableness and openness traits were correlated with the self-perceptions of oral health and aesthetics of the participants. Dental asymmetry seems to be better tolerated than lip asymmetry. Personality traits are weakly but significantly correlated with the aesthetic preference and oral health values, conscientiousness and openness being the most relevant domains in this sense.

Impact of metal and ceramic fixed orthodontic appliances on judgments of beauty and other face-related attributes

INTRODUCTION

Physical attributes, behavior, and personal ornaments exert a direct influence on how a person's beauty and personality are judged. The aim of this study was to investigate how people who wear a fixed orthodontic appliance see themselves and are seen by others in social settings.

METHODS

A total of 60 adults evaluated their own smiling faces in 3 different scenarios: without a fixed orthodontic appliance, wearing a metal fixed orthodontic appliance, and wearing an esthetic fixed orthodontic appliance. Furthermore, 15 adult raters randomly assessed the same faces in standardized front-view facial photographs. Both the subjects and the raters answered a questionnaire in which they evaluated criteria on a numbered scale ranging from 0 to 10. The models judged their own beauty, and the raters assigned scores to beauty, age, intelligence, ridiculousness, extroversion, and success.

RESULTS

The self-evaluations showed decreased beauty scores (P <0.0001) when a fixed orthodontic appliance, especially a metal one, was being worn. There was no statistically significant difference between the 3 situations in the 6 criteria analyzed.

CONCLUSIONS

A fixed orthodontic appliance did not affect how personal attributes are assessed. However, fixed orthodontic appliances apparently changed the subjects' self-perceptions when they looked in the mirror.

Lip asymmetry and smile aesthetics

Objective : To determine if lip asymmetry can affect lip aesthetics. Setting and Participants : A group of dentists (n = 40) and cleft patients (n = 40) were recruited from the dental hospital and cleft service. Interventions : Still photographic digital images of lips and teeth were manipulated to produce a computerized gradient of smile appearance with different degrees of upper-lip vertical asymmetry. These five photographs (with 0 mm representing "symmetry," and 1, 2, 2.5, and 3 mm, asymmetries) were assessed by participants using a 5-point Likert scale. Statistics : Descriptive statistics in addition to chi-square test were used to analyze the data. In order to satisfy the requirement of the chi-square test, the five smile ratings were reduced to three. Results : Lip asymmetry did affect relative smile aesthetics, as determined by dentists and cleft patients. Both the dentists and cleft patients rated the 0-mm photograph more attractive than the 2.5-mm and 3-mm smiles (P < .05). The 0-, 1-, and 2-mm smiles were indistinguishable for both dentists and cleft patients. Conclusion : Lip asymmetry affects smile aesthetics. However, cleft patients and dentists were tolerant of minor asymmetries. This suggests that small degrees of lip asymmetry do not affect relative smile aesthetics as much as large degrees of lip asymmetry (2.5 mm or more).

Effect of occlusal plane on smile attractiveness

OBJECTIVE

To determine the influence of the occlusal plane angle on smile attractiveness as perceived by a group of adult orthodontic patients and dentists.

MATERIALS AND METHODS

The first stage utilized a laboratory approach to record changes in vertical tooth position at different occlusal plane angles using a maxillary model mounted on an articulator. In the second stage, photographic manipulation was undertaken, using data from stage 1, to produce a computerized prediction of the appearance of the smile at differing occlusal plane angles (0, 5, 10, 15, and 20 degrees). Finally, the five developed photographs were assessed by participants.

RESULTS

Alterations in the occlusal plane angle did affect relative smile attractiveness for both patients (n  =  66) and dentists (n  =  66). For patients, the 10 degree smile was rated better than the 0 and 20 degree smiles (P < .01); for dentists, the 15 degree smile was rated better than the 0 and 20 degree smiles (P < .01). The 5, 10, and 15 degree smiles were indistinguishable for patients, and the 10 and 15 degree smiles were indistinguishable for dentists.

CONCLUSION

Changing the occlusal plane angle does affect relative smile attractiveness. However, patients were more tolerant of these changes than dentists. This suggests that large changes in the occlusal plane angle would affect relative smile attractiveness, and small changes are unlikely to affect smile attractiveness.

Emotional prosody rarely affects the spatial distribution of visual attention

Emotional manipulations have been demonstrated to produce leftward shifts in perceptual asymmetries. However, much of this research has used linguistic tasks to assess perceptual asymmetry and there are therefore two interpretations of the leftward shift. It may reflect a leftward shift in the spatial distribution of attention as a consequence of emotional activation of the right hemisphere; alternatively it may reflect emotional facilitation of right hemisphere linguistic processing. The current study used two non-linguistic attention tasks to determine whether emotional prosody influences the spatial distribution of visual attention. In a dual-task paradigm participants listened to semantically neutral sentences in neutral, happy or sad prosodies while completing a target discrimination task (Experiment 1) and a target detection task (Experiments 2 and 3). There was only one condition in one experiment that induced perceptual asymmetries that interacted with emotional prosody, suggesting that task-irrelevant emotional prosody only rarely directs attention. Instead a more likely cause of the leftward perceptual shift for comprehension of emotional speech is facilitation of right hemisphere linguistic processing.

Evaluation of well-balanced lip position by Japanese orthodontic patients

INTRODUCTION

The purposes of this study were to assess and determine the range of a well-balanced anteroposterior lip position as evaluated by orthodontic patients from a series of varying lip positions in facial silhouettes, and whether the rater's sex and age were factors in the assessment.

METHODS

The average profiles were constructed from 30 Japanese male and female subjects with normal occlusion. A series of 13 profiles was developed for males and females, respectively. The lips were protruded or retruded by 1-mm increments from the average profile. One hundred fifty Japanese orthodontic patients were asked to choose the top 3 most-favored, well-balanced profiles for each sex.

RESULTS

The orthodontic patients tended to prefer a slightly retruded lip position than the average facial profile for both the male and female profiles. There was no significant difference between male and female raters in selecting the top 3 most-favored profiles. In the comparison of age groups, the over 30-year-old patients significantly preferred a more retruded lip position than did the 15- to 19-year-old and the 20- to 29-year-old patients for the female profile.

CONCLUSIONS

These results suggest that, when we formulate a treatment plan, we should ask the patients about lip position before we start treatment.

Spatial statistics of gaze fixations during dynamic face processing

Social interaction involves the active visual perception of facial expressions and communicative gestures. This study examines the distribution of gaze fixations while watching videos of expressive talking faces. The knowledge-driven factors that influence the selective visual processing of facial information were examined by using the same set of stimuli, and assigning subjects to either a speech recognition task or an emotion judgment task. For half of the subjects assigned to each of the tasks, the intelligibility of the speech was manipulated by the addition of moderate masking noise. Both tasks and the intelligibility of the speech signal influenced the spatial distribution of gaze. Gaze was concentrated more on the eyes when emotion was being judged as compared to when words were being identified. When noise was added to the acoustic signal, gaze in both tasks was more centralized on the face. This shows that subject's gaze is sensitive to the distribution of information on the face, but can also be influenced by strategies aimed at maximizing the amount of visual information processed.

Lateralization of visuospatial attention across face regions varies with emotional prosody

It is well-established that linguistic processing is primarily a left-hemisphere activity, while emotional prosody processing is lateralized to the right hemisphere. Does attention, directed at different regions of the talker's face, reflect this pattern of lateralization? We investigated visuospatial attention across a talker's face with a dual-task paradigm, using dot detection and language comprehension measures. A static image of a talker was shown while participants listened to speeches spoken in two prosodic formats, emotional or neutral. A single dot was superimposed on the speaker's face in one of 4 facial regions on half of the trials. Dot detection effects depended on emotion condition--in the neutral condition, discriminability was greater for the right-, than for the left-, side of the face image, and at the mouth, compared to the eye region. The opposite effects occurred in the emotional prosody condition. The results support a model wherein visuospatial attention used during language comprehension is directed by the left hemisphere given neutral emotional prosody, and by the right hemisphere given primarily negative emotional prosodic cues.

Smile attractiveness. Self-perception and influence on personality

OBJECTIVES

To investigate self-perception of smile attractiveness and to determine the role of smile line and other aspects correlated with smile attractiveness and their influence on personality traits.

SUBJECTS AND METHODS

Participants judged their smile attractiveness with a patient-specific questionnaire. The questionnaire contained a spontaneous smiling photograph of the participant. Objective smile-line height was measured using a digital videographic method for smile analysis. Personality was assessed with the Dutch Personality Index.

RESULTS

Cronbach's alpha for the smile judgment questionnaire was .77. The results showed that size of teeth, visibility of teeth, and upper lip position were critical factors in self-perception of smile attractiveness (social dimension). Color of teeth and gingival display were critical factors in satisfaction with smile appearance (individual dimension). Participants, smiling with teeth entirely displayed and some gingival display (two to four millimeters), perceived their smile line as most esthetic. Smiles with disproportional gingival display were judged negatively and correlated with the personality characteristics of neuroticism and self-esteem. Visibility and position of teeth correlated with dominance.

CONCLUSION

The results of this research underpin the psychosocial importance and the dental significance of an attractive smile.

Reliance on Visible Speech Cues During Multimodal Language Processing: Individual and Age Differences

The current study demonstrates that when a strong inhibition process is invoked during multimodal (auditory-visual) language understanding: older adults perform worse than younger adults, visible speech does not benefit language-processing performance, and individual differences in measures of working memory for language do not predict performance. In contrast, in a task that does not invoke inhibition: adult age differences in performance are not obtained, visible speech benefits language performance, and individual differences in working memory predict performance. The results offer support for a framework for investigating multimodal language processing that incorporates assumptions about general information processing, individual differences in working memory capacity, and adult cognitive aging.

Asymmetries for the visual expression and perception of speech

This study explored asymmetries for movement, expression and perception of visual speech. Sixteen dextral models were videoed as they articulated: 'bat,' 'cat,' 'fat,' and 'sat.' Measurements revealed that the right side of the mouth was opened wider and for a longer period than the left. The asymmetry was accentuated at the beginning and ends of the vocalization and was attenuated for words where the lips did not articulate the first consonant. To measure asymmetries in expressivity, 20 dextral observers watched silent videos and reported what was said. The model's mouth was covered so that the left, right or both sides were visible. Fewer errors were made when the right mouth was visible compared to the left--suggesting that the right side is more visually expressive of speech. Investigation of asymmetries in perception using mirror-reversed clips revealed that participants did not preferentially attend to one side of the speaker's face. A correlational analysis revealed an association between movement and expressivity whereby a more motile right mouth led to stronger visual expressivity of the right mouth. The asymmetries are most likely driven by left hemisphere specialization for language, which causes a rightward motoric bias.