Do different vertical positions of maxillary central incisors influence smile esthetics perception?

Orthodontic clinicians' attitudes and knowledge of dentogingival aesthetics: A cross-sectional survey of BOS members

OBJECTIVE

To assess orthodontic clinicians' knowledge and attitudes towards dentogingival aesthetics and to explore characteristics that predict the knowledge of dentogingival aesthetics.

DESIGN

Cross-sectional questionnaire.

SETTING

On-line survey of members of the British Orthdontic Society.

MATERIALS AND METHODS

An 11-item online questionnaire was sent to orthodontic practitioners for completion. The questionnaire covered respondent demographics and questions relating to both knowledge and attitudes towards dentogingival aesthetics (six parameters). Descriptive statistics were calculated for study characteristics and summary values for the survey items. Responses to the eight knowledge-based questions were converted to a binary outcome (correct and incorrect answer). The maximum score that could be achieved was eight. Multivariable modelling was used in order to examine associations between the study characteristics and the aggregate score.

RESULTS

A total of 252 responses were obtained resulting in a response rate of 17%. Within this cohort, the respondents were primarily women (52.8%) and aged 30-40 years (35.7%). The mean score for the eight knowledge-based questions was 3.8 ± 1.8 (range = 0-8). Knowledge of the ideal gingival margin position of the anterior teeth was high (92.4%). Knowledge of the other five dentogingival aesthetic parameters was variable. In the multivariable analysis, lower knowledge scores were predicated by respondents who did not have a special interest in dental aesthetics (-0.54; 95% confidence interval [CI] = -1.01 to -0.07; P = 0.02), who could not recall attending courses, lectures or seminars on dental aesthetics in the past five years (-0.80; 95% CI = -1.43 to -0.17; P = 0.01) and with increasing age (-0.43; 95% CI = -0.62 to -0.23; P < 0.001).

CONCLUSION

Knowledge of ideal dentogingival parameters is generally suboptimal among orthodontists in the UK. The reported lack of knowledge of the ideal dentogingival parameters may also influence respondents' attitudes towards the importance of dentogingival aesthetics. Further teaching or courses related to dentogingival aesthetics is desired by orthodontic clinicians.

Aging changes in maxillary anterior teeth in untreated individuals: an observational longitudinal study

OBJECTIVE

The aging of the occlusion and tooth wears influence the smile design This study aimed at evaluating the aging changes of maxillary anterior teeth in nontreated subjects.

METHODS

The sample comprised dental models of 23 subjects (13 male, 10 female) with normal occlusions, taken at 13 (T1), 17 (T2) and 61 (T3) years of age. The following variables were measured in the maxillary anterior teeth using digital dental models: crown width/height proportion, anterior view width, crown angulation, gingival and incisal steps between central/lateral incisors and central incisors/canines. Interphase comparisons were evaluated using repeated measures analysis of variance followed by Tukey tests or Friedman tests. Sexual differences were evaluated using t tests (P < 0.05).

RESULTS

From 13 to 61 years of age, a decrease of crown width/height proportion (P = 0.008 and P =  < 0.001, for the lateral incisor and canines, respectively) and mesiodistal angulation (P =  < 0.001, P = 0.001 and P = 0.025 for the central incisor, lateral incisor and canines, respectively) of the maxillary anterior teeth were observed. The steps of the gingival margin and the incisal steps decreased with aging.

CONCLUSIONS

From adolescence to late adulthood, untreated individuals with normal occlusions demonstrated changes in the maxillary anterior teeth that may impair the smile esthetics and attractiveness.

Does different vertical position of maxillary central incisors in women with different facial vertical height affect smile esthetics perception?

BACKGROUND

The aim of this study was to assess the esthetic perceptions of orthodontists, prosthodontists and laypersons with regard to different vertical positions of the maxillary central incisors related to lateral incisors for different facial vertical height cases.

SUBJECT AND METHODS

Frontal full-face photographs showing social smiles of three adult women aged between 18 and 25 years were used. Vertical position of the maxillary central incisor was changed (intruded or extruded) with 0.5 mm increments according to the reference gingival line resulting five images for each woman in a full-face view yielding a total of 15 images. A visual analog scale was placed below each smile to allow the raters to evaluate the attractiveness of each smile independently. One-way analysis of variance was used to determine whether there was a difference between more than two independent groups in terms of quantitative variables. Comparisons of more than two dependent groups were examined with repeated measures one-way ANOVA. The significance level was taken as 0.05 for all analyses.

RESULTS

For increased facial vertical height, the highest scores for orthodontists were given to the 0.5 mm extruded (64.18 ± 26.36), for prosthodontists to the control (57.28 ± 19.80), and for layperson to the 1 mm extruded (61.27 ± 25.98) central incisor position. For decreased facial vertical height, the highest scores were obtained at the 0.5 mm intrusion with an increasing pattern from orthodontists to laypersons (63.95 ± 22.08 for orthodontists, 79.87 ± 21.43 for prosthodontists, and 79.88 ± 19.17 for laypersons). All three rater groups gave the highest scores to the 0 mm (control) smile design for normal facial vertical height. When these scores were compared among the groups, laypersons gave significantly higher scores compared to orthodontists (p < 0.001) and prosthodontists (p = 0.005).

CONCLUSIONS

The facial vertical height significantly affected the perception of smile esthetics. Keeping the distance between the central and lateral incisors longer than 1 mm in individuals with increased facial height may be important in terms of increasing patient satisfaction in terms of clinical aesthetics. On the contrary, keeping the distance between the central and lateral incisors shorter than 1 mm may create a more esthetically acceptable result in individuals with short facial height.

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

INTRODUCTION

Regarding the key role of the maxillary canine in dynamic occlusion and smile esthetics, this study investigated the relation between smile esthetics and maxillary canine torque and vertical position from the viewpoint of orthodontists, general dentists, and laypersons.

METHODS

In this descriptive cross-sectional study, the close-up smile images have been changed using Adobe Photoshop (Adobe Systems, San Jose, Calif). Then, groups of 21 orthodontists, 20 general dentists, and 33 laypersons evaluated the smile attractiveness of the images using a digital version of a visual analog scale. Statistical analysis was performed using SPSS software (version 25; IBM, Armonk, Calif) and Shapiro-Wilk, analysis of variance, and Tukey post-hoc statistical tests. The significance level was set at 0.05.

RESULTS

There was no significant difference in the mean score between the 3 groups of observers regarding the changes in the canine vertical position in none of the variations (P >0.05). Regarding variations in torque, there was a significant difference between the 3 groups of observers in the bilateral 5° torque change. (P = 0.020).

CONCLUSIONS

Unilateral changes in the vertical position had lower scores, which shows that symmetry is very important in smile esthetics. In addition, laypersons did not find torque changes ranging between -15° to 15° a significant factor in smile esthetics. Overall, some adherence to these values will be acceptable in dental treatments.

A Descriptive Study of Some of the Dento-Gingival Components of Esthetics of Patients at a Tertiary Care-center in the Eastern Part of Nepal

Background

The purpose of this study was to observe and describe some of the dento-gingival components of esthetics like the mean gingival zenith position (GZP) with respect to the vertical bisected midline axis (VBM), relative gingival zenith level (GZL) of lateral incisors (LIs), heights and widths of central incisors (CIs), LIs, and their ratios.

Materials and Methods

This cross-sectional, hospital-based, descriptive study was conducted from Feb 2019 to Aug 2019. Ethical clearance was taken from the Institutional Review Committee of B. P. Koirala Institute of Health Sciences. Convenience sampling was done. Variables (above mentioned) were marked and measured on the casts with a calibrated digital vernier caliper and entered in the data sheet, and descriptive analysis was done with SPSS version 20.

Results

A total of 210 subjects of the age group 18–25 years were included in the study. Mean GZP of the right CI was 0.49 ± 0.54 mm, of the left CI was 0.42 ± 0.43 mm, of the right LI was 0.20 ± 0.34 mm, of the left LI was 0.04 ± 0.35 mm, of the right C (Canine) was 0.023 ± 0.38 mm, and of left C was 0.07 ± 0.38 mm. Mean relative GZL of LI was about 0.40–0.41 mm below the reference line. Mean height of the right CI was 9.34 ± 0.93 mm, and that of the left CI was 9.31 ± 0.87 mm; that of the right LI was 7.91 ± 0.98 mm, and that of the left LI was 7.92 ± 0.91 mm. Mean width of the right CI was 8.34 ± 0.57 mm, and that of the left CI was 8.38 ± 0.48 mm; that of the right LI was 6.62 ± 0.58 mm, and that of the left LI was 6.66 ± 0.53 mm.

Conclusions

Mean GZP of each upper anterior tooth was distally located with respect to VBM; that of CI was more distally placed than LI and C. Relative GZL of LI was below the reference line. The central incisor width/height ratio obtained was >80% that means a squarer tooth.

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.

Esthetic and functional rehabilitation of peg-shaped maxillary lateral incisors: Practical recommendations

Peg-shaped maxillary lateral incisors cause many functional and esthetic major consequences in affected patients. Their esthetic and functional rehabilitations are often multidisciplinary, involving different clinical procedures like periodontal, orthodontic, or prosthodontic procedures. No exhaustive protocol has been established to improve their comprehensive management by general dentists or specialists. The aim of this article is to elaborate a simplified clinical protocol of complete management of peg-shaped maxillary lateral incisors by a multidisciplinary team (general practitioners, orthodontists, and prosthodontists). A clinical case of two peg-shaped maxillary lateral incisors completely rehabilitated with multidisciplinary approaches including orthodontic treatment and restoration by veneers and direct composite resin, according to the established protocol. Extraoral, intraoral, and smile clinical analysis are crucial to ensure optimal rehabilitation. Treatment results previsualization via wax-up and/or mock-up play a key role in the communication between practitioner and patient to help the latter make decision. These options also facilitate the achievement of a multidisciplinary approach by accurately estimating the number of dental movements and the type of restorations that are most suitable to the presenting clinical situation.

Orthodontists' preferences regarding the difference of bracket bonding height between the maxillary incisors

Introduction:

The vertical position of orthodontic brackets in maxillary incisors may influence the incisal step between the anterior teeth and thereby interfere with the smile esthetics. Even so, esthetic standards have been modified over time and consistently required technical adjustments.

Objective:

This study analyzed orthodontists’ preferences regarding the difference of bracket bonding height between the maxillary central incisors (MCI) and maxillary lateral incisors (MLI), and further determined whether the orthodontist sex, age and time of specialization have association to their choices.

Methods:

This study collected data through an electronic form. Study participants analyzed a clinical case in which they indicated their preference for bracket bonding height. The placement height options ranged from 3.0 mm to 5.5 mm from the incisal edge, with 0.5-mm intervals, or at the clinical crown center (CCC). The difference in the bonding height between the MCI and MLI was analyzed, considering the formation of incisal steps between these teeth.

Results:

Participants indicated that the difference in bracket bonding height between the MCI and MLI should be as follows: 0 mm (3.9%); 0.5 mm (78.3%); 1 mm (7.6%); 1.5 mm (0.2%); and CCC (9.9%). There was no statistically significant correlation between the choice for bracket bonding height and sex, age and time since specialization.

Conclusion:

Most participating orthodontists choose the 0.5-mm difference in bracket placement height between the MCI and MLI. The variables sex, age and time since specialization did not influence this choice.

Impact of variations in maxillary lateral incisor dimensions on smile esthetics

INTRODUCTION

Dentofacial esthetics has become an increasingly important topic in recent years among orthodontic patients, so it is suggested that the esthetic perspectives of clinicians and patients be considered when planning orthodontic treatment. The maxillary lateral incisors play a key role in smile esthetics. The purpose of this study was to investigate the effect of dimensional changes of the maxillary lateral incisors on smile esthetics as perceived by orthodontists, general dentists, and laypersons.

METHODS

This was a descriptive cross-sectional study. A photograph showing an attractive smile was selected. The dimensions of the maxillary lateral incisors were edited with photograph editing software to represent variations in width, crown length, gingival height, and mesial angulation. Groups of orthodontists, general dentists, and laypersons (n = 16 per group) evaluated the smile attractiveness of the images using the Likert scale according to smile esthetics criteria. Statistical analysis was performed using SPSS software (version 25) and Kruskal-Wallis statistical test. The significance level was set at 0.05.

RESULTS

There was no significant difference between mean scores of lateral incisor golden proportion changes, vertical crown length changes, gingival height changes, and mesial angulation changes (P >0.05). All groups found 1 mm more incisally positioned gingival height of lateral incisor than the central incisor and 1 mm more apically positioned incisal edge of lateral incisor than the central incisor to be the most attractive. In the group of orthodontic specialists, the 20° mesial angulation and in the other 2 groups the 10° and 15° mesial angulation had the highest score.

CONCLUSIONS

Partial deviations from the ideal esthetic proportions were not detected by laypersons, general dentists, or orthodontists and are acceptable and even attractive from the point of view of patients. Some adherence to these ratios will be acceptable in dental treatments.

Patterns of Facial Profile Preference in a Large Sample of Dental Students: A Cross-Sectional Study

The objective of this study was to explore dental students’ facial profile preferences in a large sample of students. Nine hundred and nineteen dental students of four dental schools were involved. As part of a larger study on dentofacial esthetics, six photo series consisting of one unaltered and four altered variants of the same female profile were distributed among the students. The altered features were ones that are esthetically significant according to the literature. The students had to indicate the photo in each series that they preferred. The data were analyzed in a regression model in which preference in the given photo series was the dependent variable and gender, grade of studies, and dental school were the factors. Eight hundred and sixty-one students (93.7%) responded. Gender and dental school were not associated with the observed preferences, but the grade of studies was associated for three of the modified parameters: chin prominence, the sagittal position of the maxillary dental arch, and the simultaneous modification of the prominence of the chin and the nose. This study has confirmed several earlier observations, and new observations have also been made. We have demonstrated that the anteroposterior position of the maxillary incisors may be an important determinant of profile esthetics, even if this position does not influence the situation of the soft tissues and if the forehead cannot be used as a reference. We have also shown that the harmony between the nose and the chin overrides the importance of their individual dimensions.

Esthetic Smile Perception Among Dental Students at Different Educational Levels

Purpose

To evaluate the perception of six esthetic components of the smile among dental students and whether such a perception was influenced by different education levels and gender.

Materials and Methods

This was an analytical cross-sectional study. A self-administered questionnaire was applied to all students (n=182) at clinical levels (year four and five) to evaluate a total of 6 ideal images (smile arc [SA], buccal corridor [BC], gingival display [GD], midline diastema [MD], crown length [CL] and width [CW]). In addition, students were asked to evaluate 20 altered images of these ideal images. A 10-point visual analogue scale was used to assess the ideal images, with the right end of the scale labeled “attractive smile” and represented by the number 10 and the left end of the scale labeled “unattractive smile” and represented by the number 0. The opposite scoring was applied for the altered esthetics smile images. Descriptive statistics was run to report sample characteristics, and the Mann-Whitney U-tests were performed to compare clinical levels and gender on aspects of esthetic smile.

Results

The response rate was 80% (77 females and 68 males). Students at level five scored statistically significantly (p<0.001) higher towered attractive esthetic smile in ideal SA, while students at level four scored statistically significantly (p=0.016 and 0.006, respectively) higher towered attractive esthetic smile in ideal GD and CL. At altered smile esthetics images evaluation, fifth year dental students scored statistically significantly (p=0.030, 0.026 and 0.028, respectively) higher towered unattractive esthetic smile in two altered images of SA and one of BC. In contrast, fourth year dental students scored statistically significantly (p=0.022, 0.048, 0.027, respectively) higher towered unattractive esthetic smile in one altered image of GD, midline diastema and crown width. Males in year four were more likely to score higher than females for ideal images meanwhile females in year five scored higher than males towards attractive smile in ideal images. Males and females differences in scoring ideal images on both levels were generally non-significant (P>0.05) although males were statistically significantly to score higher than females towards unattractive images in both levels (p<0.05).

Conclusion

Dental students at the fifth-year level of study had higher perception of esthetic components of smile than those at the fourth-year level. At each level of study, female dental students apparently had higher perceptions of smile esthetics than males.

Relationships between the upper central incisor crown forms and degree of labial inclination, overbite, and overjet in Japanese young adults

PURPOSE

The present study aimed to investigate the relationships between the crown form of the upper central incisor and their labial inclination, overbite, and overjet.

MATERIALS AND METHODS

Maxillary and mandibular casts of 169 healthy dentitions were subjected to 3D dental scanning, and analyzed using CAD software. The crown forms were divided into tapered, square, and ovoid based on the mesiodistal dimensions at 20% of the crown height to that at 40%. The degree of labial inclination of the upper central incisor was defined as the angle between the occlusal plane and the line connecting the incisal edge and tooth cervix. The incisal edges of the right upper and lower central incisor that in contact with lines parallel to the occlusal plane were used to determine the overbite and overjet. One-way ANOVA was performed to compare the labial inclination, overbite, and overjet among the crown forms.

RESULTS

The crown forms were classified into three types; crown forms with a 20%/40% dimension ratio of 1.00±0.01 were defined as square, >1.01 as tapered, and <0.99 as ovoid. The labial inclination degree was the greatest in tapered and the least in square. Both overbite and overjet in tapered and ovoid were higher than those in square.

CONCLUSION

Upper central incisor crown forms were related to their labial inclination, overbite, and overjet. It was suggested that the labial inclination, overbite, and overjet should be taken into consideration for the prosthetic treatment or restoring the front teeth crowns.

Does the presence of maxillary midline diastema influence the perception of dentofacial esthetics in video analysis?

OBJECTIVE

To evaluate the influence of a midline diastema on dentofacial esthetic perceptions of orthodontists, restorative dental specialists or prosthodontists, and laypersons in a frontal facial evaluation performed by means of video.

MATERIALS AND METHODS

Two individuals aged between 20 and 25 years, one of each gender, with presence of a midline diastema were selected. An acrylic resin mockup was made of the maxillary anterior region, simulating ideal conditions of smile esthetics. Four standardized frontal view videos of the complete face were filmed of each individual in the following situations: with the ideal smile (unchanged mockup) and with the presence of midline diastemas of 0.5, 1.0, and 1.5 mm created by the mockup. In all videos, the patient said a certain sentence and, at the end, simulated a posed smile. Dentofacial esthetic perceptions of all four videos of each individual were evaluated by 51 orthodontists, 51 restorative dental specialists or prosthodontists, and 51 laypersons by means of visual analog scales. Data were evaluated using analysis of variance and Tukey post hoc test, with the level of significance set at 5%.

RESULTS

The most attractive videos for all groups of examiners were those without diastema and with a diastema of 0.5 mm, for both the woman and the man. For a diastema of 1 mm or 1.5 mm, the dentofacial characteristics were considered unesthetic.

CONCLUSIONS

Diastemas equal to or greater than 1 mm negatively influence dentofacial esthetics in a frontal facial evaluation performed by means of video.

Perceptions of Dentists and Non-Professionals on Some Dental Factors Affecting Smile Aesthetics: A Study from Vietnam

Aim: It is important to meet the aesthetic expectation regarding the smile concept of both dentists and non-professionals after treatment is complete. Therefore, the study aims to evaluate the effects of altered displays in incisors, gingival margin, and other smile-related-factors on dentists’ vs. non-professionals’ aesthetics perceptions. Materials and method: We altered the features of 42 digital smile photographs to generate the changed displays in incisors, gingival margin, and other smile-related-factors. Then, these altered photographs were presented to 51 dentists and 51 non-professionals, and each picture was rated by each participant with a visual analog scale ranging from 0 (very ugly) to 100 (very beautiful). Results: We found that the alterations in incisors, gingival margin, and other factors affected studied groups’ aesthetic perception of smile. The ugly smile threshold rated by both groups for crown length of maxillary central incisors was 2.0 mm. This threshold was 2.5 mm for dentists, with moving the gingival margin of maxillary lateral incisors to the incisal ridge. The ugly thresholds for other smile-related-factors were different between studied groups; for example, the ugly thresholds for gingival exposure levels were 3 and 4mm for dentists and non-professionals, respectively. Thus, our data indicate that altered displays in incisors, gingival margin, and other smile-related-factors affected perceptions of both studied groups on smile aesthetics, but dentists tended to feel more refined than non-professionals. Dentists and non-professionals had significantly different aesthetic perceptions of the alteration of the gingival exposure level. Conclusion: Both dentists and non-professionals’ perceptions should be fully considered during orthodontic and prosthodontic treatment to achieve optimum aesthetic results.

Does the vertical position of maxillary central incisors in men influence smile esthetics perception?

INTRODUCTION

The aim of this study was to investigate whether there is any influence on the perception of smile esthetics among orthodontists and laypersons, with regard to different vertical positions of the maxillary central incisors.

METHODS

Frontal smile photographs digitally altered at full-face view and close-up view of 2 adult men aged between 20 and 30 years were used. Six vertical positions of the central incisors were created, with changes of 0.5 mm. The images were randomly assembled in an album that was presented to 53 orthodontists and 53 laypersons, who evaluated the attractiveness of the images by using visual analog scales. Comparison among the images was performed using 1-way analysis of variance, with Tukey post-hoc test. To compare the distribution of the mean scores between the full-face and close-up smile views, and between orthodontists and laypersons, the Student t test was used. The level of significance was established at 5%.

RESULTS

The best evaluations presented the following: (a) the gingival margins of the central incisors corresponded to, or were up to, 1 mm below the line of the canine gingival margins, and (b) the incisal step between the central and lateral incisors was from 1.0 to 2.0 mm. The smiles considered least attractive showed (a) the central incisor gingival margins were 1.0 mm above or 1.5 mm below the canine gingival margins, and (b) no step, or a step of 2.5 mm, between the central and lateral incisors.

CONCLUSIONS

The results of this study suggested that, in men, slightly extruded central incisors were esthetically more attractive than intruded incisors.

Evaluation of the attractiveness of different gingival zeniths in smile esthetics

OBJECTIVE

To evaluate the smile attractiveness of different gingival zeniths by general dentists, orthodontists and laypersons and the esthetic perception in the symmetric and asymmetric changes in gingival zeniths.

METHODS

Posed photographs of five patients were taken and digitally manipulated in Keynote software, in the gingival zenith region, in increments of 0.5 to 1mm in maxillary central and lateral incisors, symmetrically and asymmetrically, in nine different ways for each patient. The photos were then uploaded to a website, where evaluators (general dentists, orthodontists and laypersons) could observe and vote according to their esthetic perception, scoring from 1 to 10, 1 being the least attractive and 10 the more attractive. Kruskal-Wallis and Mann-Whitney tests were used for comparison.

RESULTS

Asymmetric gingival zeniths were less attractive than symmetrical gingival zeniths; gingival zenith differences greater than 1mm were perceptible in the smile attractiveness, both by laypersons, general dentists and orthodontists. When comparing maxillary central incisors with maxillary lateral incisors, the aesthetic change performed in the central incisors are more perceptible than those performed in lateral incisors, both symmetrical and asymmetrical. In a general way, orthodontists and general dentists are more critical in the evaluation and perception of gingival zenith changes, with the laypersons perceiving this change only from 1mm of maxillary right central incisor asymmetrical change.

CONCLUSIONS

Asymmetric gingival zeniths are less attractive than symmetrical ones. Gingival zenith differences greater than 1mm are perceptible in the smile attractiveness. Orthodontists and general dentists are more critical in evaluating smile esthetics.

Does the presence of maxillary central incisor edge asymmetry influence the perception of dentofacial esthetics in video analysis?

OBJECTIVE

To investigate the influence of incisal edge asymmetry of the maxillary central incisors on dentofacial esthetics among orthodontists, prosthodontists, and laypersons using video analysis.

MATERIALS AND METHODS

Full-face films of a 52-year-old afro-descendant woman displaying various levels of incisal wear in the esthetic zone were captured. An acrylic resin mockup was made of the maxillary anterior region, enabling the reproduction of an attractive smile and restoring tooth wear. Four different levels of incisal asymmetry between the upper central incisors in 0.5 mm increments were prepared from this mockup. A film was made for each level of asymmetry (0.5, 1.0, 1.5, and 2.0) and one with no asymmetry, with the patient repeating a sentence, totaling five films. After a pilot study and sample calculation, the films were evaluated by 138 examiners: 46 orthodontists, 46 laypeople, and 46 prosthodontists. Each examiner evaluated the dentofacial esthetics of each film using visual analog scales. Data collected were statistically analyzed.

RESULTS

Highest scores were awarded to the film with no asymmetry between upper centrals and the one with 0.5 mm of asymmetry. The asymmetries of 1.5 mm and 2.0 mm had the lowest scores from all three groups.

CONCLUSIONS

The results of this video analysis indicate that asymmetries equal to or greater than 1.0 mm between the upper central incisors edges jeopardize dentofacial esthetics.

Perception of facial, dental, and smile esthetics by dental students

OBJECTIVE

To comprehensively assess dental students' perception of facial, dental and smile esthetics and to assess whether such a perception varies by gender, clinical training, and Grade Point Average (GPA).

MATERIALS AND METHODS

Series of photographs were digitally manipulated involving three facial, two smile, four dental, and one gingival components. Students in preclinical and clinical levels evaluated the original and manipulated images using a visual analogue scale scored from 1 to 5 where 5 is the standard image and 1 is the least pleasant one. The responses were then analyzed using Mann-Whitney test. A P value of < .05 was considered significant.

RESULTS

Four hundred and eight dental students participated in this study. With regard to the overall esthetics, males and clinical students scored higher than females and preclinical students, respectively, did. With regard to the individual esthetic components, males had significantly higher scores in buccal corridors, midline shift, clinical crown width, and gingival marginal height, while females had significantly higher score in median diastema (P < .05). Clinical students had a better perception of facial asymmetry, gingival display, buccal corridors, and clinical crown width compared to the preclinical students. Effect of GPA was minimal and even contradictory; students with lower GPA had a better perception of midline deviation and occlusal canting than those with higher GPA scores.

CONCLUSIONS

Male dental students, and unexpectedly unlike females, have a better perception of facial and dental esthetics. Unlike GPA, whose effect was minimal, clinical training has a substantial positive effect on the assessment of beauty.

CLINICAL SIGNIFICANCE

Appropriate perception of facial, dental and smile esthetics by dental students is of paramount importance for providing adequate dental services and for improving and polishing their professionalism.© 2018 Wiley Periodicals, Inc.