Morphological Simulation of Different Incisal Embrasures: Perception of Laypersons, Orthodontic Patients, General Dentists and Orthodontists

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 Influence of Social Network Content on the Perception of Smiles—A Randomized Controlled Trial

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

Evaluation of Perceptions of Smile Esthetics by Dental Students

Background/Aim: The aim of this study was to investigate in the esthetic perceptions of 2nd grade dental students before and after training.

Material and Methods: A total of 16 photographs which contain golden ratio, buccal corridor, midline deviation, incisal embrasure, lip line, midline diastema, dark triangles and smile arc were shown to 78 dental students (33 male, 45 female). Immediately after the training about the smile esthetics, the same photos were shown again. The effect of gender on esthetic perception was also examined, in addition to assessing the effects of education on esthetic perception. Pearson Chi-square, Fisher’s Exact test and McNemar test were used in the analysis of the results.

Results: According to the results of the analysis, it was found that the answers of the smile arc before and after the education were statistically significant (p< 0.05). Accordingly, the rate of correct answers of women is statistically higher than that of men. A statistically significant difference was found between the responses to the gingival appearance in the smile before and after the education (p< 0.05).

Conclusions: Based on the limited results of this study, professional dental education may affect the esthetic evaluation of smile. There were differences in the esthetic perception of women and men.

Effects of gingival margin asymmetries on the smile esthetic perception of dental professionals and lay people

OBJECTIVE

To determine the effects of different gingival margin asymmetries of anterior tooth on the smile esthetic perceptions of dentists, prosthodontists, periodontists and lay people.

MATERIALS AND METHODS

A frontal close-up smile photo of a woman was used in this study. Image was digitally altered in order to create gingival margin asymmetries in left maxillary central, lateral incisors, and canines. Four stages of alterations were made in 0.5 mm increments. The final images were randomly assessed by 240 evaluators: 60 dentists, 60 prosthodontists, 60 periodontists, and 60 lay people. Questionnaire was carried out by a single researcher and each rater was asked to evaluate the attractiveness of the smile images by using the visual analog scale. Collected data were analyzed by using one-way ANOVA test with post hoc Scheffé test.

RESULTS

Smiles with 0.5 mm gingival margin asymmetries were found to be more esthetic, while 2 mm gingival asymmetries were less esthetic (P ˂ .001). Lay people's esthetic scores were higher than other groups in all degrees of asymmetries (P ˂ .001). Esthetic scores of canine teeth were higher than, lateral, and central teeth (P ˂ .001).

CONCLUSIONS

As the amount of asymmetries increased, esthetic scores decreased in all groups. Gingival margin asymmetries were less perceptible laterally.

CLINICAL SIGNIFICANCE

This study may help dental professionals to understand which gingival asymmetries are found by patients as esthetic or unesthetic and guides them in their dental treatment, especially in the aesthetic zone.

Aesthetic facial perception and need for treatment in simulated laterognathism in male faces of different ethnicities

PURPOSE

This study aimed to compare the aesthetic perception and treatment need in individuals of different ethnicities with various degrees of laterognathism assessed by orthodontists, oral and maxillofacial surgeons, and laypersons.

METHODS

Three male descendants of different ethnicities were assessed, in which the mandibular deviation was manipulated digitally in different angulations (from 0 to 8°). The assessment was performed by three groups (orthodontists, maxillofacial surgeons, and laypersons (n = 20)), and it consisted of scoring the degree of pleasantness of the images presented in a numerical scale and indicating or not a corrective treatment for the respective image.

RESULTS

The higher the degree of deviation, the lower the scores assigned to the image (p < 0.05). Laypersons assigned the highest scores, with a significant difference between laypersons and oral and maxillofacial surgeons (p < 0.05). In terms of treatment need according to the group of evaluators, there were no statistically significant differences among them (p > 0.05). Moreover, the increase in degree of deviation increased the perception of treatment need (p < 0.05). The African faces received the highest scores, with significant differences from the Caucasian faces (p < 0.05). The overall tendency was higher treatment indication for the Caucasian faces, with statistically significant differences from the African faces (p < 0.05).

CONCLUSION

The greater the mandibular deviation, the lower the aesthetic pleasantness. Laypersons are less critical regarding the assessment of mandibular deviation. There was no difference for treatment indication by the different groups of evaluators. In addition, ethnicity may influence the perception and treatment indication.