10 commandments of smile esthetics

Clinical audit of an artificial intelligence (AI) empowered smile simulation system: a prospective clinical trial

Smile aesthetics is an important factor to consider during orthodontic treatment planning. The aim of the present study is to assess the predictability of Invisalign SmileView for digital AI smile simulation in comparison to actual smile treatment outcomes, using various smile assessment parameters. A total of 24 adult subjects (12 females and 12 males; mean age 22 ± 5.2 years) who chose to be treated using Invisalign were prospectively recruited to have their pretreatment smiles captured using the Invisalign SmileView to simulate their new smiles before treatment was started. Patients were then treated using upper and lower Invisalign aligners with average treatment time of 18 ± 6 months. Full post-treatment records were obtained and full smile frame images of simulated smile and actual final smile of each subject were evaluated by an independent examiner using an objective assessment sheet. Ten smile variants were used to assess the characteristics of the full smile images. Significance level was set at P < 0.05. The ICC for the quantitative parameters showed that there was an overall excellent & good internal consistency (alpha value > 0.7 & > 0.9). The Independent t test was performed amongst the quantitative variables. The P value was not significant for all except maxillary inter canine width (P = 0.05), stating that for the five variables namely; philtrum height, commissure height, smile width, buccal corridor and smile index, actual mean values were similar to the simulation mean values. For the qualitative variables, the Kappa value ranged between 0.66 and - 0.75 which showed a substantial level of agreement between the examiners. Additionally, the Chi square test for the qualitative variables, revealed that the P value was found to be significant in all except lip line. This implies that only the lip line values are comparable. More optimal lip lines, straighter smile arcs and more ideal tooth display were achieved in actual post treatment results in comparison to the initially predicted smiles. Five quantitative smile assessment parameters i.e., philtrum height, commissure height, smile width, buccal corridor, and smile index, could be used as reliable predictors of smile simulation. Maxillary inter canine width cannot be considered to be a reliable parameter for smile simulation prediction. A single qualitative parameter, namely the lip line, can be used as a reliable predictor for smile simulation. Three qualitative parameters i.e., most posterior tooth display, smile arc, and amount of lower incisor exposure cannot be considered as reliable parameters for smile prediction.Trial Registration number and date: NCT06123585, (09/11/2023).

Influence of dental midline deviation with respect to facial flow line on smile esthetics-A cross-sectional study

BACKGROUND/OBJECTIVE

A contemporary concept states that dental midline deviation towards the direction of facial flow line (FFL) can mask the compromised smile esthetics. This study aimed to identify a range of midline deviations that can be perceived towards or away from the FFL influencing smile esthetics.

MATERIALS AND METHODS

A cross-sectional study was conducted using a frontal smile photograph of an adult female. The photograph was altered on Adobe Photoshop software into six different photographs by deviating the dental midlines towards and away from the FFL. A constant deviation of chin towards the left side was incorporated in all the photographs. Forty-three laypersons (LP) and dental professionals (DPs) evaluated those photographs. Independent t-test was used to compare the perception of dental midline deviation between LP and DPs. Simple linear regression was run to identify the factors associated with the scoring.

RESULTS

A statistically significant difference was observed for picture two with 4 mm towards FFL in the perception of midline deviation between LP and DPs. LP could not perceive the midline deviations up to 4 mm while DPs were able to perceive deviations above 2 mm. The greater the age the better the scores were and female raters had a greater inclination towards poor scores.

CONCLUSIONS

From 2 to 4 mm of midline deviation towards the FFL can be tolerated by LP and DPs.

CLINICAL SIGNIFICANCE

These findings underscore the importance of considering facial symmetry in orthodontic and cosmetic dental treatments to optimize smile esthetics.

Evaluation of vertical marginal discrepancy and load-to-failure of monolithic zirconia and lithium disilicate laminate veneers manufactured in different thicknesses

OBJECTIVES

This study aimed to evaluate the feasibility of monolithic zirconia laminate veneers (MZLV) compared to lithium disilicate laminate veneers (LDLV).

MATERIALS AND METHODS

Sixty resin replicas, each prepared with depths of 0.5 mm, 0.7 mm, and 1 mm, were produced using a 3D printer from acrylic teeth. Laminate veneers of these thicknesses were milled from pre-sintered monolithic zirconia (3rd generation) and lithium disilicate blocks. The intaglio surface of MZLV was treated with air abrasion using 110 μm diameter silica-modified aluminium oxide particles and ceramic primer, while LDLV was etched with etchant gel and treated with the ceramic primer before cementation with resin cement. Vertical marginal discrepancy (VMD) was assessed using a stereomicroscope, and a load-to-failure test was conducted using a universal testing machine. Failure modes were evaluated macroscopically on fractured surfaces. Data were analysed statistically using Two-way ANOVA and Bonferroni correction (α = 0.05).

RESULTS

LDLV samples exhibited significantly larger VMD compared to MZLV samples across all thicknesses, especially in cervical, palatal, and mean data. Within the LDLV group, load-to-fracture values for 0.7 mm and 1.0 mm thicknesses were similar, whereas for 0.5 mm thickness, it was significantly lower. In the MZLV group, load-to-fracture values were lower for 0.7 mm and 1.0 mm thicknesses compared to LDLV, but higher for 0.5 mm thickness.

CONCLUSIONS

Material choice and restoration thickness significantly influence laminate veneer restorations' success. MZLV generally exhibits superior vertical marginal fit compared to LDLV, with varying load-to-failure values across different thicknesses. Clinical management of debonding in MZLV is simpler compared to restoration fracture in LDLV.

CLINICAL RELEVANCE

Considering clinical factors, MZLV may be a preferable option to LDLV for this restoration with the thickness of 0.5 mm.

Laypersons' Assessment of Smile Esthetics in Young Individuals in Ha'il, Saudi Arabia

INTRODUCTION

When planning esthetic dental treatments, understanding smile preferences is important for dental professionals. This study aimed to evaluate the impact of selected smile characteristics on the attractiveness of young Saudis as assessed by Saudi laypersons and explore gender-preferred changes in smile attractiveness.

METHODOLOGY

This observational study assessed the dynamic smile attractiveness of 168 Saudi individuals (84 males and 84 females), selected through non-probability convenience sampling. Dynamic smiles were elicited by viewing comedic content and captured with a camera standardized for consistent positioning. Videos were edited and adjusted to images, and the frames with the most pronounced smiles were chosen. The intra-rater reliability was assessed using intra-class correlation coefficients (ICCs) and Cohen's kappa tests (κ). The highest and lowest 25th percentiles were categorized as attractive and unattractive smiles, respectively, on the visual analog scale (VAS) by laypersons. Six smile characteristics - anterior smile line, smile arc, upper lip curvature, posterior teeth displayed, smile index, and smile symmetry - were quantitatively evaluated from these images for each participant and classified into attractive and unattractive groups based on laypersons' VAS evaluations. Continuous variables were tested with the Mann-Whitney U test, and for the categorical variables, the Chi-square test was applied. The significance was set at 5%.

RESULTS

 The four randomly selected out of the 22 raters had good VAS reliability; ICCs varied from 0.661 to 0.94, with an average of 0.737, and Cohen's kappa tests for smile characteristics showed values from 0.617 to 0.89. Good agreement was also found with the smile index, with ICCs of 0.775, and dynamic smile symmetry, with ICCs of 0.872. Laypersons rated female smiles as more attractive compared to male smiles (P = 0.004). Low or average anterior smile lines (P = 0.001 for males; P = 0.03 for females), parallel smile arcs (P = 0.001 for males; P = 0.02 for females), and higher smile indexes (P = 0.001 for males; P = 0.004 for females) were significantly attractive, showing no significant gender differences.  Conclusions: Laypersons reliably rated the young Saudis' dynamic smiles as attractive. Of the rated smile characteristics, those with a low or average anterior smile line, parallel smile arcs, and a larger smile index were deemed more attractive. This study's findings show no significant gender differences in the impact of the studied smile characteristics on attractiveness. This study's findings can help dental professionals customize treatment plans that meet patients' expectations.

Influence of orthodontic bracket prescription on smile attractiveness in patients with different sagittal skeletal patterns: A 3-dimensional cross-sectional study

INTRODUCTION

The objective of this study was to evaluate the influence of orthodontic bracket prescription on smile attractiveness.

METHODS

Three women were chosen according to their sagittal skeletal pattern: skeletal Class I, II, or III malocclusion. For each, 3 smiling pictures were taken in frontal, oblique, and lateral views. The maxillary arch was then scanned, and a 3-dimensional digital model was constructed on the OrthoAnalyzer software. The information of 3 orthodontic prescriptions, namely Roth, MBT, and Ricketts, was simulated after the virtual placement of orthodontic brackets on 10 maxillary teeth. The simulations were then superimposed on the smile photographs in the 3 views, creating a total of 27 images. Groups of orthodontists, dentists, and laypeople rated the attractiveness of each smile using the visual analog scale.

RESULTS

This study included 167 evaluators: 54 orthodontists, 54 dentists, and 59 laypersons. In terms of orthodontic prescription, MBT esthetic scores were 4% lower than Roth scores (P <0.001), and Ricketts scores were 13.6% lower than Roth scores (P <0.001). In terms of skeletal pattern, Class II and III scores were 15.0% and 16.4% lower than Class I scores, respectively (P <0.001). Regarding the smiling view, oblique view scores were 3.1% lower than frontal view scores (P = 0.031), whereas lateral view scores were 8.4% lower than frontal view scores (P <0.001). In contrast to gender and age, the specialty of the evaluators significantly affected the esthetic rating of the smiles.

CONCLUSIONS

The attractiveness of a smile is affected by the prescription of the brackets. The Roth prescription tends to obtain the most favorable esthetic scores, especially in sagittal smiling images. Profile smiles with excessively proclined incisors are considered unattractive. Different views of the same smile do not get similar esthetic scores because sagittal views are rated the most severely.

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.

Effect of incisal preparation design on the fracture strength of monolithic zirconia-reinforced lithium silicate laminate veneers

PURPOSE

This study aimed to assess the fracture resistance of monolithic zirconia-reinforced lithium silicate laminate veneers (LVs) fabricated on various incisal preparation designs.

MATERIALS AND METHODS

Sixty maxillary central incisors with various preparation designs were 3D-printed, 15 each, including preparation for: (1) LV with feathered-edge design; (2) LV with butt-joint design; (3) LV with palatal chamfer; and (4) full-coverage crown. Restorations were then designed and manufactured from zirconia-reinforced lithium silicate (ZLS) following the contour of a pre-operation scan. Restorations were bonded to the assigned preparation using resin cement and following the manufacturer's instructions. Specimens were then subjected to 10,000 thermocycles at 5 to 55°C with a dwell time of 30 s. The fracture strength of specimens was then assessed using a universal testing machine at a crosshead speed of 1.0 mm/min. One-way ANOVA and Bonferroni correction multiple comparisons were used to assess the fracture strength differences between the test groups (α = 0.001). Descriptive fractographic analysis of specimens was carried out with scanning electron microscopy images.

RESULTS

Complete coverage crown and LV with palatal chamfer design had the highest fracture resistance values (781.4 ± 151.4 and 618.2 ± 112.6 N, respectively). Single crown and LV with palatal chamfer had no significant difference in fracture strength (p > 05). LV with feathered-edge and butt-joint designs provided significantly (p < 05) lower fracture resistance than complete coverage crown and LV with palatal chamfer design.

CONCLUSION

The fracture resistance of chairside milled ZLS veneers was significantly influenced by the incisal preparation designs tested. Within the limitation of this study, when excessive occlusal forces are expected, LV with palatal chamfer display is the most conservative method of fabricating an indirect restoration.

Analysis of recurrent esthetic dental proportion of natural maxillary anterior teeth: A systematic review

STATEMENT OF PROBLEM

The recurrent esthetic dental (RED) proportion has been a benchmark for the rehabilitation of the maxillary anterior teeth of North American patients. While it has been evaluated in other populations, the global application of RED proportions in the rehabilitation of maxillary anterior teeth is unclear.

PURPOSE

The purpose of this systematic review was to examine the existing evidence on dental proportion to evaluate the existence of RED proportions in the esthetic smile in different geographic regions.

MATERIAL AND METHODS

A systematic search was conducted by reviewing different databases. The focused question was "Does RED proportion exist in esthetically pleasing smiles in different populations around the world?" The search included articles with a combination of MeSH keywords based on dental proportion from January 2000 to July 2020. The titles and abstracts were identified by using a search protocol. Full text of the articles was independently evaluated. The systematic review was modified to summarize the relevant data. The general characteristics, outcomes, and quality of studies were reviewed and analyzed systematically.

RESULTS

Seventeen studies were selected from the reviewed articles. Three studies were conducted in Europe, 10 in South Asia, and 4 in Western Asia. Eleven studies found that the mean perceived ratio of anterior teeth was not constant when progressing distally. Five studies reported that the ratio was constant in a small percentage of their populations, and 1 suggested that the ratio was constant if it remains between 60% and 80%. The central-to-LI and Ca-to-LI proportion values were not constant. Overall, the Ca-to-LI proportion values were higher than the central-to-LI proportions.

CONCLUSIONS

RED proportions were not found in the successive widths of maxillary anterior teeth among the reviewed data from different geographic regions. RED proportions are not the only standard for restoring esthetic smiles worldwide, and anterior tooth proportions differ among populations based on their race and ethnicity.

Comparison of pleasant and unpleasant smile characteristics in the perception of the laypeople in an Iranian population

INTRODUCTION

This study aimed to compare the characteristics of pleasant and unpleasant smiles from the perception of laypeople.

METHODS

Two-hundred posed smile photographs were obtained from adult participants with no anomaly, restoration, or severe crowding and spacing in anterior teeth. Photographs were shown to 26 judges to give each photograph a score for attractiveness. Upper and lower quartiles for the most and least rated smiles were determined, and variables including gingival display, smile arc, midline deviation, buccal corridor, smile width, tooth rotation or malposition, diastema, upper and lower vermilion show, and tooth form were measured. Independent-sample t test and Pearson chi-square analysis were used to determine the differences between the pleasant and unpleasant groups for quantitative and qualitative variables, respectively. The linear regression model revealed variables with the most significant impact on the mean score.

RESULTS

All quantitative and qualitative variables except tooth form significantly differed between pleasant and unpleasant smile groups (P <0.05). The consonant smile arc was associated with an increase of 12.59% in mean scores compared with the inconsonant smile arc. Each tooth reported with malposition was correlated with a decrease of 9.37% in the scores. In the same way, each 1-mm increase in midline diastema and occlusal cant coincided with a drop of 8.73% and 3.59% in scores, respectively.

CONCLUSIONS

The results of this study suggested that smile arc, tooth malposition, midline diastema, and occlusal plane canting had the most impact on smile esthetics and should be given priority by orthodontists in the treatment plan of choice.

Management of ankylosed teeth using the decoronation technique: integrative literature review and case report

INTRODUCTION

The decoronation technique has been described in literature since 1984 and, based on the available results, it can lead to considerable benefits for the repair and rehabilitation of ankylosed teeth. Based on these reports, one could expect that this procedure would be well known by the dental community. However, this fact does not seem to be true, and this procedure is not widely used.

METHODS

The objective of this paper is to present appropriate literature that discusses decoronation and evaluate the perspectives of the procedure, both in relation to the technique and the long-term benefits for the patient. An integrative literature review at PubMed, ScieELO, and Lilacs databases was performed using the keywords "decoronation", "ridge preservation decoronation", "decoronation ankylosis". In addition, a case report will be presented to demonstrate the technique in a systematic and detailed manner.

RESULTS

Considering the inclusion criteria, 27 articles that present consistency regarding decoronation were selected.

CONCLUSION

There is scarce availability of scientific works related to the topic, to corroborate and discuss the technique. The present paper reinforces the benefits of this procedure, and revisit decoronation, attempting to provide a possible treatment for ankylosed teeth in growing patients.

Evaluation of gingival porcelains: Color change and surface properties

PURPOSE

This in vitro study aimed to evaluate the effect of thermal cycling (TC) on the color stability, translucency, and surface roughness of two different gingival porcelain materials.

MATERIALS AND METHODS

The gingival porcelains IPS e.max Ceram Gingiva (Ceram) and IPS InLine Gingiva (InLine) were tested. A total of 66 disc-shaped specimens were prepared and glazed using porcelain powders of G1, G3, and G5 colors. The samples were divided into two porcelain groups by their types and into three subgroups (n11) by their colors. Thermal cycling was performed at 6000 cycles simulating an oral environment of 5 years. The color and surface roughness measurements of the samples were made before and after the thermal cycling. Color measurements were made with a spectrophotometer. Surface roughness (mean surface roughness [Ra; μm]) was measured using a contact profilometer. Data before thermal cycling were evaluated using the Kruskal-Wallis test followed by the Dunn Bonferonni paired comparison test. Two-way ANOVA with repeated measurements and a pairwise comparison test with Bonferroni correction were used to evaluate the change in roughness and translucency parameter (TP) data between groups due to thermal cycling.

RESULTS

The color change was below the clinically perceptible color change threshold (∆E00 = 2.1) in all groups after thermal cycling. However, all materials had significantly increased roughness (p < 0.05). An increase in roughness was detected in the Ceram group and was higher than that in the InLine group. The change in the translucency parameters of the samples after thermal cycling was not statistically significant; a small increase was observed in all groups. The highest translucency values ​​were seen in the G1, G3, and G5 colors.

CONCLUSIONS

Thermal cycling caused a significant increase in the roughness values ​​(Ra) of all materials and a minimal increase in their translucency. The color change of gingival porcelains after thermal cycling was less than the clinically perceptible threshold.

Color stability and degree of conversion of gingiva-colored resin-based composites

OBJECTIVES

To evaluate gingiva-colored resin-based composites' (GCRBC) color stability and degree of conversion (DC%).

METHODS

Eight discs (8 × 1 mm) of 20 shades of GCRBC were prepared. Color coordinates were measured against a gray background with a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45°/0° geometry at baseline and after 30 days of storage in distilled water, coffee, and red wine. Color differences ( ∆ E 00 ) between final and baseline conditions were calculated. An ATR-FTIR spectrometer with a diamond tip was used to calculate DC%. The results were analyzed statistically using ANOVA and Tukey post-hoc test. The level of significance was p < 0.05.

RESULTS

DC% and color stability correlated with each other and with the GCRBC brand. DC% ranged between 43% and 96%, highest values correspond to flowable composites. All composites have experienced color changes after immersion in water, wine and coffee. However, the magnitude of the color change has varied widely depending on the immersion medium and the GCRBC. Color changes generated by the wine were, globally, greater than those induced by coffee (p < 0.001) and above the acceptability thresholds.

CONCLUSIONS

The DC% of GCRBCs is sufficient to achieve adequate biocompatibility and physicomechanical properties, but the high susceptibility to staining could compromise aesthetic long-term results.

CLINICAL SIGNIFICANCE

The degree of conversion and the color stability of gingiva-colored resin-based composites correlated with each other. All composites have experienced color changes after immersion in water, wine and coffee. Color changes generated by wine were, globally, greater than those induced by coffee and above the acceptability thresholds that could compromise aesthetic long-term results.

Smile Aesthetics Assessment in Patients Undergoing the Finishing Phase of Orthodontic Treatment: An Observational Cross-Sectional Study

Objective To describe the smile characteristics of patients entering the finishing phase of orthodontic treatment. Methods This observational study involved a non-probabilistic sample of 48 patients. Clinical records served as the basis for determining the type of treatment (with or without extractions). Photographs were analyzed to obtain smile variables. Dental casts and panoramic radiographs were evaluated to ascertain the cast-radiograph evaluation (CRE) index. Univariate and bivariate analyses were conducted at a significance level of 0.05. Results The study evaluated 24 men and 24 women, with an average age of 20.10 ± 6.78 years. Fifty percent of the patients did not undergo extractions, and the average CRE index for the sample was 34.83 ± 9.01. Regarding the smile, a medium smile line was prevalent in 66.7% of cases, and a non-consonant smile arc was observed in 58.3%. Significant differences in the smile arc were found between patients with and without extractions (p=0.019). Right and left buccal corridors measured 2.52 mm ± 1.52 and 2.43 mm ± 1.37, respectively. The upper dental midline deviated by 0.80 ± 0.91 mm and had an angulation of 1.65 ± 2.05º. Both variables showed significant differences between Class I and Class II patients (p=0.020; p=0.027). Symmetrical smiles were also observed (1.05 ± 0.17). Conclusions Based on our findings, clinicians should focus on the smile arc in patients who have not undergone extractions and on the midline inclination in Class II patients. These appear to be the most common areas for improvement in patients who are in the finishing phase of treatment. Additionally, considerable variability exists in the smile characteristics of patients still undergoing orthodontic treatment, leaving room for further enhancement of results.

The Interference of Age and Gender on Smile Characterization Analyzed on Six Parameters: A Clinical-Photographic Pilot Study

Background and Objective: This study aimed to evaluate six smile-esthetic parameters (deviation of the upper dental midline from the facial midline, upper lip curvature, smile line, smile arch, smile width, and shape of the maxillary central incisors), correlating them with age and gender. Materials and methods: Caucasian individuals (N = 114) were grouped by gender (male and female) and age (group I—18 to 30 years old; group II—31 to 50 years old; and group III—over 50 years old). Using a digital camera, extra and intraoral pictures were taken to analyze the variables above-mentioned. The data were statistically evaluated, considering a significance level of p < 0.05. Results: Most participants found deviations of the upper dental midline, straight upper lip curvature, and the medium smile line coincided with the facial midline. The parallel smile arch exposing 9 to 11 upper teeth, the absence of exposure of lower teeth when smiling, and oval upper incisors were prevalent parameters. Regarding gender, significant results were found for the curvature of the upper lip (p = 0.049), the smile arch (p = 0.001), and the shape of the upper central incisors (p = 0.004). For age, the association with the curvature of the upper lip (p = 0.032), the smile line (p = 0.001), the smile arch (p = 0.007), the width of the smile exposing lower teeth (p = 0.002), and the shape of the upper central incisors (0.012) were significant. Conclusions: Within this study’s limitations, gender and age affect the anterior teeth shape and upper lip curves; gender and age did not influence the coincidence between dental and facial midlines.

A novel pictorial smile chart: Reliability and validity

INTRODUCTION

Smile analysis provides data on the positive and negative elements of a patient's smile. We aimed to develop a simple pictorial chart to record relevant parameters of the smile analysis in a single diagram and to investigate the reliability and validity of this chart.

METHODS

A panel of 5 orthodontists developed a graphical chart, which was reviewed by 12 orthodontists and 10 orthodontic residents. The chart comprises facial, perioral, and dentogingival zones analyzing 8 continuous and 4 discrete variables. The chart was tested on frontal smiling photographs of 40 young (aged 15-18 years) and 40 old (aged 50-55 years) patients. All measurements were performed twice with an interval of 2 weeks by 2 observers.

RESULTS

Pearson's correlation coefficients for observers and age groups varied from 0.860 to 1.000 and between observers from 0.753 to 0.999. Minor significant mean differences were found between the first and second observations, which were not clinically relevant. The kappa scores for the dichotomous variables were in perfect agreement. To test the sensitivity of the smile chart, differences between the two age groups were assessed as differences because aging is expected. In the older age group, philtrum height and visibility of mandibular incisors were significantly larger, whereas the upper lip fullness and buccal corridor visibility were significantly lesser (P <0.001).

CONCLUSIONS

The newly developed smile chart can record essential smile parameters to aid diagnosis, treatment planning, and research. The chart is simple and easy to use, has face and content validity and good reliability.

Effect of various orthodontic adhesives on enamel colour changes after fixed treatment

BACKGROUND

The aim of this study was to compare enamel colour changes of incisors and canines produced by various orthodontic adhesives following treatment with fixed appliances.

METHODS

The study included 300 maxillary and mandibular central and lateral incisors, and canines of 25 subjects who finished fixed appliance treatment. The following adhesives were used according to the manufacturer's instructions: Transbond XT (3M Unitek, Monrovia, CA, USA), Kurasper F (Kuraray Europe GmbH, Frankfurt, Germany), Grengloo (Ormco Corporation, Glendora, CA, USA) and Light Bond (Reliance Orthodontic Products, Itasca, IL, USA). Different adhesives were placed in each quadrant of the subjects. Pretreatment and posttreatment enamel colours were evaluated at the middle third of the buccal surfaces of teeth using the SpectroShade Micro Dental Colour Complete Tooth Analysis System^TM (MHT International, Verona, Italy). Tooth colour was determined using the Commission Internationale de l'Eclairage L* a* b* system, and ∆E values were calculated.

RESULTS

Pretreatment and posttreatment intragroup comparison results showed significant decreases in L* and b*, as well as insignificant changes in a* for all teeth. Significantly less enamel colour changes occurred in the Kurasper F group compared with the Grengloo and Light Bond groups. Evaluating incisors and canines separately, overall intergroup comparisons were not significant. Enamel colour changes were significantly less only for the canines compared to the incisors in the Transbond XT and Kurasper F groups. The ∆E values were 1.83-2.18 and 1.41-1.95 for incisors and canines, respectively.

CONCLUSION

Although statistically less enamel colour changes occurred in the Kurasper F group compared with the Grengloo and Light Bond groups, the observed changes were not clinically relevant.

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.

Treatment of an anterior open bite, bimaxillary protrusion and mesiocclusion by the extraction of premolars and the use of clear aligners

An anterior open bite may be orthodontically treated by either the intrusion of posterior teeth, the extrusion of anterior teeth, or a combination of both. An improvement in bimaxillary protrusion often involves the extraction of premolars and the retraction of the anterior teeth. The treatment of mesiocclusion mainly involves the mesial and/or distal movement of the molars. However, these three types of malocclusions pose significant treatment challenges when using clear aligners. The present case report describes the treatment of a 24-year-old female patient who presented with the above characteristics, which affected her confidence, willingness to smile and masticatory function. A four-premolar extraction plan was designed to resolve the problems using clear aligners as the patient rejected fixed or visible appliances. After 33 months of orthodontic therapy, except for the counter-clockwise rotation of the mandible and the decrease of facial height, the other objectives established in the pre-treatment plan were achieved, and the patient was satisfied with the results. The combination of clear aligners and premolar extractions effectively corrected the skeletal anterior open bite, bimaxillary dentoalveolar protrusion, and mesiocclusion.

Comparison between clear aligners and 2 × 4 mechanics in the mixed dentition: a randomized clinical trial

OBJECTIVES

To compare the efficacy and efficiency between clear aligners and 2 × 4 fixed appliances for correcting maxillary incisor position irregularities in the mixed dentition.

MATERIALS AND METHODS

The sample comprised 32 patients from 7 to 11 years of age randomly allocated into two parallel treatment groups: the clear aligners group, 14 patients (6 girls, 8 boys) with a mean initial age of 9.33 years (standard deviation [SD] = 1.01) treated with clear aligners; and the fixed appliances group, 13 patients (9 girls, 4 boys) with a mean initial age of 9.65 years (SD = 0.80) treated with partial (2 × 4) fixed appliances. Digital models were acquired before treatment and after appliance removal. Primary outcomes were incisor irregularity index and treatment time. Secondary outcomes were arch width, perimeter, length, size and shape, incisor leveling, incisor mesiodistal angulation, plaque index, and white spot lesion formation (International Caries Detection and Assessment System index). Intergroup comparisons were evaluated using t-tests or Mann-Whitney U-tests with Holm-Bonferroni correction (P < .05).

RESULTS

Treatment time was approximately 8 months in both groups. No intergroup differences were observed for changes in any of the variables. Similar posttreatment arch shapes were observed in both groups.

CONCLUSIONS

Clear aligners and 2 × 4 mechanics displayed similar efficacy and efficiency for maxillary incisor position corrections in the mixed dentition. The choice of appliance should be guided by clinician and family preference.

The visual perception of aligned and crowded maxillary lateral incisors when smiling via eye tracking

Background

This study aimed to investigate whether the alignment of the teeth while smiling alters the visual perception by laypeople using eye tracking.

Methods

Facial images (two males and two females) were digitally edited to show a smile pattern with aligned teeth and one with crowded teeth. Sixty laypeople were selected to observe the images. The number of fixations, fixation duration, and time until the first fixation were recorded using an eye-tracking system. The results were qualitatively calculated with dot maps. Numerical data were analyzed using an independent Student's t test.

Results

There were no significant differences in fixation duration and the number of fixations in the crowded smile, mainly that of the male. The fixation times for the teeth were significantly different when the participants viewed the male subjects with a crowded smile (P<0.05). Dot maps showed greater attention to the smile with crowded teeth in both genders.

Conclusion

The crowded maxillary incisor smile attracted more visual attention to males from laypeople.

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 role of botulinum toxin A in the management of different types of excessive gingival display: a systematic review

Background An aesthetic smile displays a symmetrical 2 mm or less of gingival tissue. A smile with over 3 mm of gingival display can be deemed socially unaesthetic, impacting on a patient's psychosocial status. This literature review aimed to explore the role of botulinum toxin A as a treatment modality for different types of excessive gingival display (EGD) and appropriate treatment protocols.Methods A systematic search of the literature dating from 1980 onwards was conducted using electronic databases (Medline, Scopus and Web of Science). The Fowkes and Fulton quality assessment was undertaken to review the level of bias.Results Nine prospective studies were assessed for the number and site of injections, the unit dosage, the reconstitution and the improvement of EGD. Guidelines for treatment of EGD were constructed for operator consideration.Conclusions The data from this study elucidated that botulinum toxin is an effective treatment for all types of EGD caused by hyperfunctional smile muscles. It can be regarded as a safe treatment that reversibly improves facial aesthetics in patients suffering from gummy smile due to hyperactive musculature. Botulinum toxin was confirmed to be useful as a diagnostic tool and palliative treatment, as well as an adjunctive therapy in the treatment of a gummy smile.

Smile Analysis: Diagnosis and Treatment Planning

Smile design is defined as the process of creating an esthetic smile based on scientific and artistic guidelines established through studies, perception, and cultural and racial standards that have been recognized over time. Smile design is a dynamic field with evolving trends that take into consideration: facial esthetics, lip dynamics, pink and white esthetics, and personality. Traditional smile design focused on the orodental complex. Modern smile designers must have a global understanding of the entire patient to design the perfect smile.

Crown Lengthening Techniques and Modifications to Treat Excessive Gingival Display

Dental aesthetics are a fundamental treatment goal in dentistry, in which even minute deviations from the ideal may necessitate corrective treatment or constitute a suboptimal clinical outcome. A well-defined protocol that adheres to sound biological and surgical principles is necessary to harmoniously integrate the dental and periodontal components. This article reviews clinical and aesthetic guidelines based on these principles for clinical crown lengthening.

Contemporary Smile Design: An Orthodontic Perspective

Orthodontists play a vital role in the smile design of individuals. There are a variety of orthodontic goals and tooth movements that can be achieved to obtain the ideal smile that ultimately leads to the optimum esthetic outcomes. In this article, some methods and appliance systems to control and achieve the desired tooth movements are described and illustrated.

Influence of violet LED associated or not with peroxide gel on inflammation, mineralization, and collagen fiber maturation in dentin and pulp tissue

OBJECTIVES

To evaluate the influence of violet LED, associated or not with a 17.5% hydrogen peroxide (HP) bleaching gel, on inflammation, mineralization in pulp tissue, and collagen fiber maturation in dentin and pulp tissue.

MATERIALS AND METHODS

The maxillary molars of eighty Wistar rats were distributed into four groups (n = 10): CONT - without treatment; HP - 30-minute application of 17.5% HP; LED - 20-minute application of violet LED; and HP+LED - application of PH and violet LED. Rats were euthanized and jaws were processed for histologic and immunohistochemical evaluation (IL-17, IL-23, and osteocalcin) and picrosirius red immediately after (T0), and at 7 (T1), 15 (T2), and 30 days (T3) post-treatment, with Wilcoxon, Mann-Whitney, paired T-test, and T-test (α = 0.05).

RESULTS

HP and HP+LED presented necrosis and severe inflammatory infiltrate. When compared to CONT group, LED presented severe osteocalcin (OCN) immunostaining in T2 and less immature fibers in T2 and T3.

CONCLUSION

The violet LED caused no severe damage to the pulp tissue, increased IL-17 and IL-23 expression in T0 when associated with HP, and had no influence on pulp tissue mineralization, besides accelerating the maturation of collagen fibers of dentin.

CLINICAL RELEVANCE

Violet LED therapy induced no inflammation in the pulp tissue of rats and played no role in pulp tissue fibrosis, besides accelerating the maturation of dentin collagen fibers.

Characteristics and Dental Indices of Orthodontic Patients Using Aligners or Brackets

Background. Clear aligners have become a treatment alternative to metal brackets in recent years due to the advantages of aesthetics, comfort, and oral health improvement. Nevertheless, few studies have analyzed the clinical characteristics and dental indices of orthodontic patients using aligners or brackets. Methods. A total of 170 patients received orthodontic treatment at Chang Gung Memorial Hospital in 2021. Patients were stratified by types of treatment (Invisalign® clear aligner (n = 60) or metal bracket (n = 110). Results: Patients were aged 26.1 ± 7.2 years, and most were female (75.0%). The Invisalign® group was older than the bracket group (p = 0.003). The skeletal relationships were mainly Class I (49.4%), followed by Class II (30.0%) and Class III (20.6%). The molar relationships were primarily Class I (38.8%), followed by Class II (37.1%) and Class III (24.1%). The decayed, missing, and filled tooth (DMFT) index was 9.9 ± 6.0, including 2.1 ± 2.9 for decayed teeth, 0.5 ± 1.1 for missing teeth, and 7.3 ± 4.3 for filled teeth. There were no significant differences in the DMFT index or skeletal and molar relationships between the groups (p > 0.05). The index of complexity outcome and need (ICON) was 56.8 ± 13.5, and the score was lower in the Invisalign® group than in the bracket group (p = 0.002). Among the variables included in the ICON assessment, only the aesthetic variable was lower in the Invisalign® group than in the bracket group (p < 0.001). The Frankfort-mandibular plane angle was 27.9 ± 5.1 degrees. Finally, the E-line of the lower lip was lower in the Invisalign® group than in the bracket group (1.5 ± 2.4 versus 2.8 ± 3.1, p = 0.005). Conclusions. Older patients showed a greater intention to choose Invisalign® treatment for improving the appearance of their teeth than younger patients, who chose metal bracket treatment. The demand for Invisalign® aligner treatment for aesthetic reasons was substantial. A soft tissue profile with more protrusive lower lips and a greater need for orthodontic treatment was found in the bracket group.

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.

Proposed parameters of optimal central incisor positioning in orthodontic treatment planning: A systematic review

OBJECTIVE

Planning of incisal position is crucial for optimal orthodontic treatment outcomes due to its consequences on facial esthetics and occlusion. A systematic summary of the proposed parameters is presented.

METHODS

Studies on Google Scholar©, PubMed©, and Cochrane Library, providing quantitative information on optimal central incisor position were included.

RESULTS

Upper incisors supero-inferior position (4-5 mm to upper lip, 67-73 mm to axial plane through pupils), antero-posterior position (3-4 mm to Nasion-A, 3-6 mm to A-Pogonion, 9-12 mm to true vertical line, 5 mm to A-projection, 9-10 mm to coronal plane through pupils), bucco-lingual angulation (4-7° to occlusal plane perpendicular on models, 20-22° to Nasion-A, 57-58° to upper occlusal plane, 16-20° to coronal plane through pupils, 108-110° to anterior-posterior nasal spine), mesio-distal angulation (5° to occlusal plane perpendicular on models). Lower incisors supero-inferior position (41-48 mm to soft-tissue mandibular plane), antero-posterior position (3-4 mm to Nasion-B, 1-3 mm to A-Pogonion, 12-15 mm to true vertical line, 6-8 mm to coronal plane through pupils), bucco-lingual angulation (1-4° to occlusal plane perpendicular on models, 87-94° to mandibular plane, 68° to Frankfurt plane, 22-25° to Nasion-B, 105° to occlusal plane, 64° to lower occlusal plane, 21° to A-Pogonion), mesio-distal angulation (2° to occlusal plane perpendicular on models).

CONCLUSIONS

Although these findings can provide clinical guideline, they derive from heterogeneous studies in terms of subject characteristics and reference methods. Therefore, the optimal incisal position remains debatable.

Peg-Shaped Lateral Incisors Treated with Ceramic Three-Quarter Crown

In recent years, patients' expectations are becoming higher in terms of esthetic dentistry. Having the ideal smile is becoming a purpose as the appearance of stars and famous persons have been undoubtedly improved through smile correction. Peg-shaped lateral incisors are a common dental form aberration which could distort the smile and may hamper patient psychology because of the smaller shape and size in disharmony with other teeth. Three-quarter ceramic veneers are a mini-invasive approach which could solve the esthetic problem of peg-shaped teeth and ensure patient's satisfaction. The present paper was about a clinical case with peg-shaped lateral incisors treated with three-quarter ceramic crowns. It would also highlight the preparation particularities.

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.

The Impact of Dental Midline on Asymmetric Faces: Perspective of Laypersons and Dentists

Background: The objective was to determine if asymmetric facial features, nasal and chin deviations, affect the perception of attractiveness of a dental midline angulation, and if it is consistent among both dentists and laypeople. It was also analyzed if factors, such as the sex, age group of the participants and the dentist’s area of operation are relevant in their assessment. Methods: A cross-sectional study, approved by the Ethics Committee of Fernando Pessoa University. From a symmetrical facial model (SFM) image, a natural-looking asymmetrical face was created. Based on this asymmetric facial model six images were created, with different directions and degrees of inclination of the dental midline. In total, 236 laypersons and 242 dentists completed the online questionnaire where they rated the self-perception of attractiveness of the eight images (VAS scale from 0 to 10). Non-parametric comparisons (IBM© SPSS Statistics vs. 27.0, p < 0.05). Results: The results showed a significant difference in the perception of attractiveness between laypeople and dentists. This finding was consistent regarding every image, except for the SFM. The factors, sex of the people participating and dentist’s area of operation, seemed only to contribute to a significant difference in the perception when it came to the SFM. The perceived attractiveness of the images, for dentists and laypersons, did not differ by age group of the participant, apart from images 6 and 8. Conclusions: Dentists are more rigorous about dental midline inclinations than laypersons. The perception of attractiveness was affected by the age group and sex of the participants and the dentist’s area of operation.

[Esthetic perception of the smile according to gingival exposure in university students in Lima, Peru, 2020]

Objective

To determine the esthetic perception of the smile according to gingival exposure in undergraduate university students of dentistry and other degrees of different ages and sex in Lima, Peru 2020, and descriptively evaluate the main variables such as age and sex.

Methodology

A woman's smile was photographed following esthetic parameters, digitally modifying gingival exposure and obtaining six digital images. The images were rated by 512 students of dentistry and other degrees by means of a virtual survey using the Visual Analog Scale (values 0 to 10).

Results

The students perceived the 0.5 mm gingival exposure smile as more attractive and the 2.5 mm gingival exposure smile as unattractive. According to age, students aged 18 to 23 years perceived the 0.5 mm gingival exposure smile as more attractive and the 2.5 mm gingival exposure smile as less attractive, while students aged 24 to 29 years perceived the 1 mm gingival exposure smile as more attractive and the 2 mm gingival exposure smile as unattractive. According to gender, both found the 0.5 mm gingival exposure smile more attractive and the 2.5mm gingival exposure smile unattractive.

Conclusions

University students of dentistry and other degrees had the same perception of the smile in relation to gingival exposure, with a smile of 0.5 mm gingival exposure being considered attractive and the 2.5 mm smile unattractive. Younger students considered the smile with 0.5 mm gingival exposure more pleasant. Students of both sexes had the same esthetic perception of the smile.

Planning and orthodontic preparation for maxillary incisors reshaping

Introduction:

Having a beautiful smile is the main desire of people seeking dental treatment. To achieve this goal, many variables must be considered. These include tooth alignment, color, shape and size, besides their harmonious relationship with the lips and face. An individualized diagnosis is essential to achieve the best result. Within this context, facial analysis and the characteristics of shape, size and position of maxillary incisors play a key role.

Methods:

This paper describes clinical situations in which interdisciplinary treatment was performed to achieve esthetic results in a conservative manner and ensuring greater stability. In most cases requiring reshaping of maxillary incisors for esthetic reasons, prior orthodontic movement is essential. The main focus of this paper is to discuss the many variables involved in these situations.

Results and Conclusion:

The results of treatments described in this paper were obtained by means of a multidisciplinary approach, involving Orthodontics and Esthetic Dentistry, acting in harmony and recognizing their possibilities and limitations, in order to offer patients the best esthetic solution for their smile. The best treatment option is not always the easiest or fastest. The dentist, as a health professional, should consider the patients’ wishes but also perform treatments with minimal intervention, and the best and most predictable esthetic result, also focusing on function and health.

Influencing Factors on Aesthetics: Highly Controlled Study Based on Eye Movement and the Forensic Aspects in Computer-Based Assessment of Visual Appeal in Upper Front Teeth

First impressions are formed by the external appearance and, in this respect, essentially by an examination of the face. In the literature, the teeth, especially the maxillary front, are among an eye-catching and sensitive area that plays a significant role in the overall evaluation of appearance. In this study, the first eye fixation of 60 subjects with different levels of dental training (layperson, trained layperson, dental student, and dentist) is recorded using an eye-tracking system, and their subsequent evaluation of the images is recorded. Ten unedited original photographs of different maxillary anterior teeth and ten subsequently edited photographs will be used to evaluate forensic aspects such as the effect of symmetry and color on the overall evaluation. The results will be used to determine which areas of the maxillary anterior are demonstrably viewed and whether knowledge of dental esthetics influences evaluation and viewing.

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.

Comparative analysis of smile aesthetics between top celebrity smile and a Southern European population

STATEMENT OF PROBLEM

The analysis of different parameters involved in the esthetic perception of the smile is important for the correct planning of cosmetic dental treatments.

PURPOSE

The purpose of this study was to analyze the differences in the main parameters of smile esthetics among celebrities identified as having the best esthetic smiles and a young Southern European population.

MATERIAL AND METHODS

The study consisted of a control group of 144 dental students from the University of Seville (69.4% women; 30.6% men) with a mean ±standard deviation age of 23.19 ±0.5 years and photographs of 58 celebrities identified as having the best esthetic smiles (74.1% women; 25.9% men) with a mean ±standard deviation age of 42.09 ±2.25 years. Photographs of the celebrities were obtained from the Internet, and standardized photographs were made of the control group. The variables measured were smile line, smile arc, incisal edges and lower lip relationship, smile width, dental midline deviation and tilting, buccal corridor widths, and angulation discrepancy between interpupillary line and commissural line and between interpupillary line and occlusal plane. The data obtained were processed in a statistical software program for a descriptive statistical analysis and for inferential analysis parametric statistical tests by applying the Wilcoxon, chi-square, Student t, and kappa index tests (α=.05).

RESULTS

Statistically significant differences (P<.01) were found between the groups in terms of smile width, smile arc, midline deviation and tilting, and angulation discrepancy between the interpupillary line and the commissural line. Smile arc was the only variable found to be different (P<.01) in relation to sex.

CONCLUSIONS

Characteristics of the most esthetic smiles were no deviation or tilting of the maxillary midline, showing a greater number of teeth in the smile, displaying incisal edges parallel to the lower lip (particularly in women), and displaying occlusal and commissural planes parallel to the interpupillary line.

The influence of elastomeric ligatures pigmentation on smile aesthetics during orthodontic treatment

AIM

To assess the influence of elastomeric ligatures, subjected to a previous in vitro pigmentation process using different substances, on smile aesthetics during orthodontic treatment, from the perception of students and professionals.

METHODS

Eight elastomeric ligatures of five commercial brands (3M/Unitek, American Orthodontics, Morelli, Ortho Technology, and Orthometric) (n=8) were immersed in coffee, Coca-Cola, and red wine for one minute per day, for 28 days; and another group of ligatures was immersed in artificial saliva. All samples were photographed and subsequently analyzed using the Adobe Photoshop software, by the RGB method. Afterwards, the pigmented ligatures were inserted in a patient wearing orthodontic brackets, and zoomed photographs of the smile were taken and presented to 40 evaluators, who filled in a satisfaction scale sheet to express their opinion on the smile aesthetics of each photograph. The color data were subjected to analysis of variance (ANOVA) and Tukey tests.

RESULTS

The substance with the highest pigmentation potential was coffee (p< 0.05) followed by red wine (p< 0.05). Comparison among the brands used in this study showed that American Orthodontics and Orthometric had the lowest degree of pigmentation when immersed in coffee and red wine (p< 0.05), respectively. However, the brand that showed the highest level of satisfaction among the evaluators was Ortho Technology.

CONCLUSIONS

The presence of pigmented elastomeric ligatures affected smile aesthetics, when compared with the control group.

A study of smile aesthetic perception among dental professionals, patients and parents towards impacted maxillary canine treatment options

OBJECTIVE

To evaluate the smile aesthetics of the different treatment options for impacted maxillary canines as perceived by orthodontists, dentists, patients and parents.

DESIGN

Cross-sectional survey.

SETTING

Four rater groups were selected to complete the questionnaire consisting of an orthodontist group, a general dental practitioner group, a patient group consisting of patients aged 11-18 years who were considered to be 'Gillick competent' and a parent group consisting of parents/guardians who accompanied the patients to their orthodontic appointments.

METHOD

Four digitally manipulated images were created to imitate different treatment options available for the treatment of ectopic maxillary canines including: alignment of the impacted maxillary canine; substituted premolars; retained deciduous canines; or gaps present. The images were embedded into piloted questionnaires. Each participant completing the questionnaire was asked to mark the visual analogue scale (VAS) beneath each image according to their perception of attractiveness of each image. Quantitative scoring of the perceived attractiveness of the smile was assessed by one calibrated assessor measuring the distance from the start of the scale to the marked cross placed on the VAS. A two-way ANOVA (mixed between-within subject's ANOVA) was used to compare perception of differences in smile aesthetics.

RESULTS

There were significant differences found in the VAS between the groups (P = 0.002) and between the treatment options (P < 0.001) There was no statistically significant difference found between the aligned canines and substituted premolars images by the patient (P = 0.2) or parent group (P = 0.5). All groups most disliked the treatment option where gaps were present at the end of treatment.

CONCLUSION

The patient and parent groups showed similar perception in smile aesthetics for aligned canines and substituted premolars and all groups showed a strong dislike to the presence of gaps. The orthodontist group showed the most critical aesthetic perceptions.

An eye-tracking and visual analogue scale attractiveness evaluation of black space between the maxillary central incisors

Objective:

To study the influence of black space between the maxillary central incisors on the aesthetic visual perception of the face, via eye-tracking and visual analogue scale (VAS).

Methods:

Black space between the central incisors was created, for both sexes, as follows: control, 1-mm black space, 2-mm black space and 3-mm black space. Ninety raters participated in this study, divided into three groups: 30 laypeople, 30 nonorthodontists, and 30 orthodontists. After the visual calibration of each observer, eight photographs were presented in the Ogama^® software concomitant with the use of the hardware The Eye Tribe^®. Ogama generated information depending on the eye-tracking of each rater, regarding the time until the first fixation, time of fixation, heatmap, scanpath, and total time of fixation, to evaluate the areas deemed to be of interest according to the raters. Later on, the VAS was used, where each rater evaluated the images in an album on a scale of zero to 10 points.

Results:

The eyes and mouth were the areas more often noticed by the raters according to the heatmaps, while no significant difference was observed in time until the first fixation between the three groups of raters (p> 0.05). However, regarding the time of fixation on the mouth, a significant difference was observed (p< 0.05) when comparing the three groups.

Conclusion:

Black space has a negative effect on the aesthetic perception of the face. The amount of attention on the mouth is correspondent to the size of the black space.

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

INTRODUCTION

In addition to understanding the basic standards of a smile and patient's opinion, dentists should take into account smile aesthetics, an essential factor for optimal outcomes. This study aimed to evaluate the factors that affect the perception of an aesthetic smile and determine its morphological characteristics and measure the gingival aesthetic parameters.

METHODS

In all, 200 Vietnamese aged 18-35 years were recruited to have their spontaneous smiles captured. These smile images were assessed by 50 laypersons and 50 dentists using a visual analogue scale measurement. The images were analysed to evaluate perceptions of evaluators, determine smile attractiveness, and measure gingival aesthetics.

RESULTS

The difference in the judgements of laypersons and dentists, males and females, and laypersons aged 18-25 and 26-35 years were nonsignificant. High or average anterior smile line, parallel smile arc, upward upper lip curvature, second premolars as the posterior-most teeth displayed, smile index of 5.23-5.63, and dynamic smile symmetry of 1 were scored highly on smile attractiveness. The following maxillary gingival aesthetic parameters were preferred: gingival zenith (GZ) of the canine 0.72-0.75 mm apical to the GZ of the central incisor; GZ of the lateral incisor 0.66 mm coronal to the gingival line; gingival line angle of ∼87°; for the central incisor, lateral incisor, and canines, distance from the GZ to the long axis of 1, 0.4, and 0 mm, respectively; interdental papilla height of 4.25, 3.60, and 3.85 mm, respectively; ratio of the distance from the GZ and the interdental papilla tip to the incisal edge of ∼1.74-1.77 mm.

CONCLUSIONS

Factors including profession, gender, and age of evaluators had almost no impact on their perception of aesthetics. Smile attractiveness characteristics and gingival aesthetic parameters have clinical applicability for patient care.

Aesthetic evaluation of the labiolingual position of maxillary lateral incisors by orthodontists and laypersons

BACKGROUND

The maxillary anterior teeth play a crucial role in smile aesthetics. Previous studies regarding the importance of maxillary lateral incisors for smile aesthetics concentrated on their size, incisor edge level, and inclination, etc. However, the aesthetic effect of lateral incisor movement in the spatial position has not been studied yet. Therefore, the purpose of this study was to explore the influence of the labiolingual position of maxillary lateral incisors on the aesthetic perception of smiles by orthodontists and laypersons, as well as analyze differences in this perception between male and female raters.

METHODS

A three-dimensional (3D) dental model was generated from the photograph of a man's smile using iOrtho7.0 software (Time Angel, Wuxi, China). Based on this model, seven images were generated with different labiolingual positions of the maxillary lateral incisors in 0.5 mm increments (+ indicating labial translation, and-indicating lingual translation). The images were evaluated by 86 orthodontists and 161 laypersons using a visual analog scale, with lower scores indicating less attractiveness. Data were analyzed using Student's t test and one-way analysis of variance with post hoc test.

RESULTS

There was no significant difference in smile ratings by males and females. Orthodontists assigned lower scores to all images than laypersons. The smile at + 1.5 mm was considered the least attractive by orthodontists, while smiles at + 1.5 mm and - 1.5 mm were regarded as the least attractive by laypersons. The smile at 0 mm was evaluated as the most attractive by all raters. Laypersons gave different scores to smiles at 0 or - 0.5 mm, but orthodontists did not.

CONCLUSIONS

The labiolingual position of maxillary lateral incisors does affect the perception of smile aesthetics. Orthodontists may rate smile aesthetics more critically than laypersons. Therefore, communication and discussion between orthodontists and patients is needed to achieve better therapeutic and aesthetic outcomes.

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.

Composite resin CAD-CAM restorations for a midline diastema closure: A clinical report

A diastema between the maxillary central incisors affects an esthetic smile and has been treated in various ways. Precise diagnosis is essential to guide the choice of the most appropriate treatment. This clinical report describes closing a maxillary midline diastema with a computer-aided design and computer-aided manufacturing (CAD-CAM) composite resin.

Photographic Evaluation, Analysis and Comparison of Aesthetically Pleasing Smiles: A Prospective Study

Objective

To evaluate the differences in aesthetically pleasing smiles and compare the smile arc parameters in males and females by dental specialists using photographs.

Methods

The study was conducted on 500 North Indian subjects (Indo-Aryan race; 212 males and 288 females) aged 17-25 years (mean age, males=21.1 years; females=23.4 years), with reasonably pleasing smiles. The facial photographs were taken using a DSLR camera. The standardized photographs were shown to 30 judges for evaluation and rated using the visual analog scale. The smiles were categorized into attractive, fair, and average. The quantification of the smile characteristics was done by using an objective method that involved identifying consonant and non-consonant smiles.

Results

The association between smile arc and smile attractiveness was significant (p=0.018) in females. The buccal corridor width was higher among those with fair to attractive smiles as compared with those with an average smile (p=0.018). Most subjects with an attractive smile had a smile arc parallel to the upper lip as compared with most subjects with a fair or average smile who did not have the smile arc in parallel (p=0.006).

Conclusion

Most females were in the fair to attractive category whereas most males were in the average to fair category. The buccal corridor width was found to be higher among those with a fair to attractive smile as compared with those with an average smile. There was an association between smile arc and smile attractiveness in females.