Dynamic smile visualization and quantification: Part 2. Smile analysis and treatment strategies

A comparative analysis of patient satisfaction with various methods of digital smile design and simulation

Background

Digital smile design (DSD) is a technique that utilizes the scientific methods and advanced software to design patients' smiles, presenting the visualized smile map directly to the patient. However, patients may not always find the proposed smile satisfactory or feel a sense of alignment with it. To address this concern, dentists have been integrating the tooth shape with the overall facial shape and other parameters to develop a personalized smile plan for each patient.

Materials and Methods

This study employed a descriptive-analytical, cross-sectional research design conducted during the summer and fall of 2022. This research sought to evaluate patient satisfaction levels associated with three distinct DSD techniques: Visagism, Proportional, and Stepwise Comprehensive. A sample of 20 participants, evenly split between males and females, was selected, all of whom were seeking smile design treatment and did not present with skeletal, jaw, facial, or periodontal complications. Interviews were conducted to analyze personality and temperament, and smile maps were created utilizing the Visagism, Stepwise Comprehensive, and Proportional methods. Subsequently, patients evaluated the designs produced by all three methods and completed a satisfaction questionnaire. Nonparametric statistical tests, namely the Kruskal-Wallis test and post hoc Bonferroni tests, were used to examine the research hypotheses at a significance level of 0.05.

Results

The results indicated a high level of satisfaction with all three DSD methods, with no statistically significant differences observed among them. These results suggest that all three approaches effectively met the patients' expectations and preferences.

Conclusion

The outcomes of this study have practical implications for dental professionals engaged in DSD, potentially enhancing patient experiences and treatment outcomes. Further research in this domain may explore the additional factors that could influence patient satisfaction and refine the DSD process.

Effects of Emotional States on Reproducibilities of Rest Position, Social and Spontaneous Smiles, and Speech

Objective

To evaluate the effect of emotional states on reproducibilities of rest position, social and spontaneous smiles, and speech.

Methods

A total of 30 individuals aged 18-22 years were included (mean age; 19.03 years ±1.03). Three emotional states were determined: amusing, sadness, and neutral. The participants watched three different videos in 3 sessions on the same day. After each video, the participants completed a questionnaire to assess their mood. The rest position, social and spontaneous smiles, and speech recordings were gathered from the participants using videographic method. Measurements were made for each function. The Friedman test, One-Way ANOVA, Kruskal-Wallis test was performed for statistical evaluations, and intra-observer correlation coefficients and Bland-Altman Limits of Agreement were calculated.

Results

In spontaneous smiles, there were significant differences between amusing and sadness in the smile height (p=0.020); amusing and sadness in the lower lip thickness (p=0.029). In social smiles there was a significant difference between amusing and sadness in the maxillary incisor display (p=0.006). There were no statistically significant differences in the rest position, but clinically significant differences were observed in some participants. In speech, a significant difference was found between amusing and sadness in the distance between the upper lip and subnasal (p=0.035).

Conclusion

The reproducibility of social and spontaneous smiles was influenced by various emotional states. However, the rest position exhibits higher reproducibility than social and spontaneous smiles in all emotional states.

Artificial Intelligence in Aesthetic Dentistry: Is Treatment with Aligners Clinically Realistic?

Smile aesthetics are increasingly prioritized in dental practice, with accurate orthodontic assessment and treatment planning being crucial for optimal outcomes. This study evaluates Invisalign® SmileView™ (SV), an AI-based tool that simulates post-treatment smiles, focusing on its ability to present potential orthodontic outcomes to patients. Background/Objectives: This research aims to study whether SV can simulate predictable orthodontic results and if it makes anatomical modifications to the teeth. Additionally, it will evaluate whether SV displays smiles that conform to the orthodontic criteria described in the literature. Finally, the study will analyze whether the software can align the dental with the facial midline. Methods: A total of 51 subjects were recruited in Madrid, Spain. The operator took a frontal photograph of the subjects with a social smile (T0), following the application's instructions. Subsequently, the subjects followed the steps to modify their smile (T1), resulting in a new image of the subject with a different smile. The following variables were collected, analyzed, and compared with the standards defined in the literature: smile width, vertical exposure of the maxillary central incisor, width of the maxillary central and lateral incisors, proportion of the maxillary lateral incisor width to the central incisor, anterior gingival exposure level, position of the upper and lower dental midlines relative to the facial midline. Results: 58% of the sample showed dental expansion, with an excessive expansion (>5 mm) observed in 8%. In the maxillary arch, 5.9% of incisors exceeded predictable aligner movement (>1.5 mm), with 3.9% showing excessive extrusion and 2% excessive intrusion. For the lateral incisors, the mesiodistal size was reduced less than 0.5 mm in 31.4% of cases, with excessive interproximal reduction (>0.5 mm) in 5.9%. Additionally, 62.7% of cases would require multidisciplinary treatment due to an increase in size. SV centered the upper midline in 77.9% of these cases. Among the sample, the upper midline was initially centered in 74.5% of subjects, and SV maintained it centered in 84.2% of these subjects. Conclusions: SV tends to generate simulations of broader smiles, which are mostly achievable through aligner treatments, from an orthodontic perspective, and showed high predictability regarding the vertical movements of the incisors that can be achieved with aligners. Moreover, it adjusted the mesiodistal size of the upper incisors in its simulations and demonstrated the ability to identify and correct deviations of the dental midlines relative to the facial midline.

Changes in smile parameters after surgical-orthodontic treatment for skeletal Class III malocclusion

Background/purpose

Many patients pursue attractive smiles, and surgical-orthodontic treatment is a common method. We aimed to analyze the changes in smile parameters after surgical-orthodontic treatment in patients with skeletal Class III pattern and identify factors influencing postoperative outcomes.

Materials and methods

This retrospective study comprised 34 patients with skeletal Class III malocclusion and pure mandible prognathism who received surgical-orthodontic treatment. Hard and soft tissue parameters were assessed through lateral cephalometry, and smile esthetics were evaluated through extraoral photography. Postoperative changes in smile parameters and between-parameter correlations were analyzed. Random forest and decision tree deep learning models were used to identify factors influencing postoperative changes.

Results

Substantial postoperative changes were observed in the buccal corridor, upper lip height, and smile index. Significant between-sex differences were noted in the upper midline and right chelion. Strong, positive correlations were found between upper lip height and upper lip ratio and between lower lip height and lower lip ratio. By contrast, strong negative correlations were observed between lower teeth exposure and smile index and between interlabial gap and smile index. The highest degrees of postoperative changes were noted in asymmetry-associated smile parameters: lower lip area, interlabial gap, smile index, buccal corridor, and arc ratio.

Conclusion

Considerable changes were noted in skeletal, dental, and soft tissue parameters after surgical-orthodontic treatment. However, the changes in smile esthetics were less prominent from the frontal view. As for chin asymmetry, the most to least prominent changes were in the lower lip area, interlabial gap, smile index, buccal corridor, and arc ratio, respectively.

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.

Measurement of vertical anterior teeth display and lip position at smiling in Kurdish population. Age and gender-based evaluation

Statement of Problem

As part of the overall facial analysis, smile analysis is an essential component of diagnosis and treatment planning in the esthetic rehabilitation of a patient with missing anterior teeth.

Purpose

The aim of this study was to investigate the effect of age and gender on the amount of maxillary anterior teeth and associated lip position during smiling in the Kurdish population to establish guidelines for rehabilitating edentulous patients.

Material and methods

Video equipment was used to capture images of 80 Kurdish subjects divided into two groups by age and sex: Forty young subjects (20 women and 20 men aged 21-24 years), and another forty old subjects (20 women and 20 men aged 45-65 years). Three frames for each subject were selected: one representing the entire length of maxillary anterior teeth, another the posed smile frame and the third representing the spontaneous widest smile. These images were used to quantify a dentogingival exposure for each anterior tooth on either side using standardized measurement techniques. The Kruskal-Wallis test was used to evaluate and compare differences in teeth and gingival display and the Chi-square test was used to explore the frequency of smile line types (α = 0.05).

Results

There were no significant age or sex differences in the anterior teeth display of posed smile. However, women displayed more maxillary anterior teeth in both age groups. The highest display was for lateral incisors, followed by central incisors and canine (61.3%, 58.9%, and 49.05% in the young group vs 62.05%, 54.5%, and 53.3% in the old group). On the other hand, a significant age difference was observed in dentogingival display of maxillary anterior teeth during a spontaneous smile, including mainly the lateral incisors length with their overlying gingiva (98.5%, 1.46 mm in young vs 92.1%, 0.47 mm in old). Women show insignificant excess gingival display than men. Low smile line (class IV) was the predominant type of smile in posed smiles (60%-62.5%). While the average smile line (class III) was the dominant type of young (52.5%) and the high (class II) of old (40%) in spontaneous smiles.

Conclusions

Age influences the dental and gingival display of anterior teeth in spontaneous smiles but not in posed smiles. Women generally show more gingiva and teeth in all the parameters evaluated than men. The predominant type of smile changed from (class IV) in posed smile to (class III) of young and to (class II) of old subjects in a spontaneous smile. Dental treatments should be individually planned according to age-related dynamic norms.

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.

Aesthetic Management of Tooth Size Discrepancies

The aesthetic management of tooth size discrepancies is an essential component when dealing with simple and complex dental rehabilitation. Tooth size and shape is a crucial factor that strongly influences both the smile and the face in the treatment outcome. From an orthodontic perspective, evaluation of the ideal mesiodistal widths relating to both maxillary and mandibular arches is required to plan the correct occlusal, aesthetic, and functional result.The aim of this paper is to propose a safe and repeatable method to evaluate and correct tooth size discrepancy through the presentation of two case reports. Both cases were managed using a combination of clear aligner therapy and minimally invasive restorative procedures, as well as the use of digital tools.

An Innovative 3D Printed Tooth Reduction Guide for Precise Dental Ceramic Veneers

Tooth reduction guides allow clinicians to obtain the ideal space required for ceramic restorations. This case report describes a novel design (CAD) for an additive computer-aided manufactured (a-CAM) tooth reduction guide with channels that permitted access for the preparation and evaluation of the reduction with the same guide. The guide features innovative vertical and horizontal channels that permit comprehensive access for preparation and evaluation of the reduction with a periodontal probe, ensuring uniform tooth reduction and avoiding overpreparation. This approach was successfully applied to a female patient with non-carious lesions and white spot lesions, resulting in minimally invasive tooth preparations and hand-crafted laminate veneer restorations that met the patient's aesthetic demands while preserving tooth structure. Compared to traditional silicone reduction guides, this novel design offers greater flexibility, enabling clinicians to evaluate tooth reduction in all directions and providing a more comprehensive assessment. Overall, this 3D printed tooth reduction guide represents a significant advancement in dental restoration technology, offering clinicians a useful tool for achieving optimal outcomes with minimal tooth reduction. Future work is warranted to compare tooth reductions and preparation time for this guide to other 3D printed guides.

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.

Perception of smile attractiveness among laypeople and orthodontists regarding the buccal corridor space, as it is defined by the eyes. An innovated technique

OBJECTIVE

To investigate whether there is a relationship between the distance between the iris and pupil with the ideal size of buccal corridors.

MATERIALS AND METHODS

A full-portrait image of a male Caucasian was used to create a set of 11 digitally modified images with different buccal corridor space. A web-based cross-sectional study was designed and distributed via an online survey to 200 laypeople and 200 orthodontists to assess image attractiveness, using a Visual analogue scale. For the statistical analysis, Wilcoxon signed-rank and Mann-Whitney U tests were used. The significance level was set at p < 0.05.

RESULTS

The response rate for laypeople was 70% (n = 139), while the rate for orthodontists was 73% (n = 146). For the layperson group, the maximum smile attractiveness score was 10% of buccal width reduction, compared to the iris-pupillary distance, while for the orthodontists, it was 20%. The attractiveness of the smile was significantly reduced in both groups when the buccal corridor width was increased in comparison to the iris-pupillary distance.

CONCLUSION

The length between the mesial part of the iris and the distal of the pupil, may constitutes a landmark for the estimation of the desired width of the buccal corridor.

CLINICAL RELEVANCE

Inter iris-pupillary distance can be the starting point in the smile designing process, in order to perform a facial driven selection of buccal corridor size.

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.

Maxillary transverse deficiency diagnosed by 3 methods and its relationship with molar angulation in patients with skeletal Class III malocclusion

INTRODUCTION

The objective of this study was to evaluate the relationship between maxillary transverse deficiency (MTD) diagnosed by 3 methods and molar angulation measured in 3-dimensions in patients with skeletal Class III malocclusion, which could give reference to the selection of diagnostic methods in MTD patients.

METHODS

Cone-beam computed tomography data of 65 patients with skeletal Class III malocclusion (mean age 17.35 ± 4.45 years) were selected and imported into MIMICS software. Transverse deficiencies were evaluated by 3 methods, and molar angulations were measured after reconstructing 3-dimensional planes. Two examiners performed repeated measurements to assess the intraexaminer and interexaminer reliability. Pearson correlation coefficient analyses and linear regressions were performed to determine the relationship between a transverse deficiency and molar angulations. One-way analysis of variance was used to compare the diagnostic results of 3 methods.

RESULTS

The novel molar angulation measurement method and 3 MTD diagnostic methods have the interexaminer and intraexaminer intraclass correlation coefficient values >0.6. The transverse deficiency diagnosed by 3 methods was significantly and positively correlated with the sum of molar angulation. There was a statistically significant difference for the transverse deficiencies diagnosed by the 3 methods. The transverse deficiency was significantly higher in Boston University's analysis than in Yonsei's analysis.

CONCLUSIONS

Clinicians ought to choose the diagnostic methods properly, considering the feature of the 3 methods and the individual difference of each patient.

Finishing Analysis of Dental Outcome (FADO) as a New Guide in Orthodontic Treatment

OBJECTIVES

Orthodontic treatment has both functional and esthetic goals. The finishing phase is one of the most important and seeks to solve occlusal, dental, functional, and esthetic problems, offering the possibility of obtaining the best possible outcome. This paper aims to describe the Finishing Analysis of Dental Outcome (FADO) guide as a tool to improve orthodontic treatment results.

METHODS

A literature review of finishing procedures and orthodontic treatment outcomes was made. Moreover, current parameters of the esthetics of the smile were considered. The information was systematized to produce a protocol applicable to practice. This guide includes the assessment of mini-esthetic, micro-esthetic, and occlusal results using the Cast Radiographic Evaluation of the American Board of Orthodontics. Treatment options for each item were also suggested. Clinical cases were used to illustrate the application of the guide.

RESULTS

The FADO Guide is presented and explained to give the clinician a systematic and orderly guide to achieve the best possible results in orthodontic treatment. To fulfill the FADO Guide, cast models, a panoramic radiograph, smile photographs (frontal and lateral), and an intraoral frontal photo are needed. The FADO Guide includes four sections: mini-esthetic evaluation (the evaluation of the smile), micro-esthetic evaluation, occlusal analysis, and radiographic analysis.

CONCLUSION

The FADO guide presents a systematic approach to the application of a finishing protocol in orthodontics. Furthermore, this guideline can improve clinical practice and be used as a checklist to optimize clinical outcomes.

Wearable Orofacial Technology and Orthodontics

Wearable technology to augment traditional approaches are increasingly being added to the arsenals of treatment providers. Wearable technology generally refers to electronic systems, devices, or sensors that are usually worn on or are in close proximity to the human body. Wearables may be stand-alone or integrated into materials that are worn on the body. What sets medical wearables apart from other systems is their ability to collect, store, and relay information regarding an individual's current body status to other devices operating on compatible networks in naturalistic settings. The last decade has witnessed a steady increase in the use of wearables specific to the orofacial region. Applications range from supplementing diagnosis, tracking treatment progress, monitoring patient compliance, and better understanding the jaw's functional and parafunctional activities. Orofacial wearable devices may be unimodal or incorporate multiple sensing modalities. The objective data collected continuously, in real time, in naturalistic settings using these orofacial wearables provide opportunities to formulate accurate and personalized treatment strategies. In the not-too-distant future, it is anticipated that information about an individual's current oral health status may provide patient-centric personalized care to prevent, diagnose, and treat oral diseases, with wearables playing a key role. In this review, we examine the progress achieved, summarize applications of orthodontic relevance and examine the future potential of orofacial wearables.

Evaluation of Change in the Facial Profile and Aesthetics in Relation to Incisor Position in Both Maxillary and Mandibular Arches

Background The orthodontist is often confronted with the need to predict soft tissue profile changes that may result from the orthodontic treatment. The problem arises because the contribution of many of the factors influencing the soft tissue profile still needs to be fully understood. The complexity of the problem is increased in growing patients in whom the post-treatment soft tissue profile is the result of both growth and orthodontic treatment. A primary motivation for seeking orthodontic treatment is a desire to improve dental and facial aesthetics. To achieve balance in the facial profile treated orthodontically, it is essential to identify the underlying skeletal hard tissue and soft tissue parameters. The present study evaluated the changes in facial profile and aesthetics in relation to incisor position. Materials and methods Samples for this study consisted of pre-treatment lateral cephalograms of the Indian population (n = 450) having different incisor relationships. Subjects aged between 18 and 30 years were included. Angular and linear measurements were taken to analyse the incisor relationship with soft tissue parameters. Results The majority (61.2%) of subjects belonged to the age group of 18-30 years. The overall female-to-male ratio in the study was 7:3. The parameter U1 to L1 was abnormal in 86.8% of subjects. Similarly, the parameters S-line upper lip (UL), S-line lower lip (LL), E-line UL, and E-line LL were found abnormal in 93.9%, 86.8%, 82.6%, and 70.1% of subjects, respectively. A significant agreement was found between U1 to L1 and E-line UL and U1 to L1 and E-line LL. Conclusions The present study concludes that facial aesthetics combines soft and hard tissue corrections, not just based on occlusal relationships but also considering facial harmony. Thus, the incisor relationship is an important asset and strongly correlates with other soft tissue and hard tissue parameters that improve facial aesthetics for the individual undergoing orthodontic treatment.

Intra- and Interrater Agreement of Face Esthetic Analysis in 3D Face Images

The use of three-dimensional (3D) facial scans for facial analysis is increasing in maxillofacial treatment. The aim of this study was to investigate the consistency of two-dimensional (2D) and 3D facial analyses performed by multiple raters. Six men and four women (25-36-year-old) participated in this study. The 2D images of the smiling and resting faces in the frontal and sagittal planes were obtained. The 3D facial and intraoral scans were merged to generate virtual 3D faces. Ten clinicians performed facial analyses by investigating 14 indices of 2D and 3D faces. Intra- and interrater agreements of the results of 2D and 3D facial analyses within and among the participants were evaluated. The intrarater agreement between the 2D and 3D facial analyses varied according to the indices. The highest and lowest agreements were found for the dental crowding index (0.94) and smile line curvature index (0.56) in the frontal plane, and Angle's classification (canine) index (0.98) and occlusal plane angle index (0.55) in the profile plane. In the frontal plane, the interrater agreements were generally higher for the 3D images than for the 2D images, while in the profile plane, the interrater agreements were high in the Angle's classification (canine) index however low in the other indices. Several occlusion-related indices were missing in the 2D images because the posterior teeth were not observed. Esthetic analysis results between 2D and 3D face images can differ according to the evaluation indices. The use of 3D faces is recommended over 2D images to increase the reliability of facial analyses, as it can fully assess both esthetic and occlusion-related indices.

Traction of impacted and stacked maxillary anterior teeth with precise biomechanics followed by torque control using gate spring

Impaction of multiple maxillary anterior teeth is a rare condition; when it occurs, it impacts the patient's chewing function and smile esthetics, and it has always been problematic for clinicians. This case report presents an 11-year-old girl with impaction of 3 adjacent maxillary anterior teeth, including labiopalatally oriented maxillary right central and lateral incisors and a mesially inclined maxillary right canine. These 3 impacted and stacked teeth were sequentially aligned after surgical exposure and orthodontic traction, and the surrounding dentigerous cyst healed simultaneously. Precise and delicate biomechanics will control root movement and prevent root collision. Gate spring, a novel torquing auxiliary, was used for highly efficient root torque movements of the previously impacted incisors. After 32-month treatment, the patient's occlusion and esthetics greatly improved.

Effects of maxillary advancement on maxillary incisor display in patients with skeletal Class III malocclusion and cleft lip and palate

INTRODUCTION

The information on the hard- and soft-tissue factors correlated with tooth display after LeFort I osteotomy, especially in the surgery-first approach (SFA), are limited. This study aimed to correlate different parameters with the maxillary incisor display in patients with skeletal Class III malocclusion and those with cleft lip and palate (CLP) in SFA.

METHODS

This study consisted of 35 patients with skeletal Class III malocclusion and 32 with cleft deformities who had undergone orthognathic surgery. Pretreatment and posttreatment lateral cephalometric analysis were obtained. Maxillary incisor display was measured in photographs. The intraclass correlation coefficient was used to assess the intraexaminer repeatability. The Student t test was used to compare the maxillary incisor display between 2 groups. Analysis of covariance was performed with pretreatment measurement as covariates, and the important determinants for maxillary incisor display were identified by adjusting the baseline measurements.

RESULTS

The mean increase of maxillary advancement at point A was 5.25 mm and 1.28 mm downward movement for skeletal Class III malocclusion, whereas it was 4.59 mm advancement and 2.16 mm downward movement for patients with CLP. The resulting maxillary incisor display was 2.86 mm for skeletal Class III malocclusion and 2.56 mm for patients with CLP. The covariates for maxillary incisor display before intervention was significantly associated with the maxillary incisor display after intervention (P <0.001). However, the interaction effect of groups was not seen (P = 0.933). The horizontal position of A, vertical position of ANS, and upper lip length were the most predictable parameters (P <0.001, P <0.001, P = 0.048, respectively) for maxillary incisor display in both groups.

CONCLUSIONS

Horizontal position of point A, vertical position of ANS, and upper lip length are the most important determinants for maxillary incisor display for patients with skeletal Class III malocclusion and those with CLP.

An Overview of Maxillofacial Approaches to Smile Design

The oral and maxillofacial surgeon (OMS) has the knowledge and skills to make drastic skeletal changes in favor of a more cosmetic smile. OMS can alter intraoral and extraoral soft tissues to make subtle or significant changes in facial cosmesis. This article provides an overview of the scope of the OMS in smile design. The authors provide a cursory review of pertinent gross and surgical facial anatomy, discuss the role of orthognathic surgery and rhinoplasty in smile cosmesis, and describe the fundamentals of common cosmetic procedures ranging from gingivoplasty to lip lift and lip augmentation and the use of neurotoxins.

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.

Smile Aesthetic Evaluation on Videographs: An Intra-Rater and Inter-Rater Agreement Study

The aim of this study was to assess on videographs the intra- and inter-rater reproducibility of the Smile Esthetic Index (SEI) that has been previously validated on photographs. Smile videographs were obtained using a smartphone associated with the Smile Lite MDP mounted on a tripod. They were then randomized and evaluated twice consecutively at a 1-week interval by three periodontists according to the SEI based on 10 variables. Cohen’s Kappa and Fleiss’ Kappa tests were performed to measure intra- and inter-rater agreement. Sixty-five smile videographs of 24 men and 41 women (mean age 33 ± 11.3 years) were scored. A mean intra-rater agreement of 0.68 (0.64–0.73) was obtained, representing substantial agreement. The inter-rater agreement calculated for each variable ranged from 0.31 for the variable “absence of visible excessive gingiva” to 0.90 for the variable “absence of diastema and/or missing inter-dental papilla.” Within the limits of this study, we have demonstrated that it was possible to use videographs to reproducibly evaluate an aesthetic score (SEI) previously validated on photographs.

A Cross-Sectional Online Survey on Knowledge, Awareness, and Perceptions of Hollywood Smile Among the Saudi Arabia Population

Background:

Hollywood smile has gained popularity in recent times to improve aesthetics among the general population. Since patients’ perceptions of dental aesthetics play a vital role in planning and evaluating cosmetic dental treatment, it is essential to understand their knowledge, awareness, and factors that influence their perceptions of dental aesthetics.

Objectives:

The objective of this study was to assess the knowledge, awareness, and perceptions of Hollywood smile among the general population in Saudi Arabia.

Methods:

A close-ended questionnaire consisting of demographic information and 20 questions related to Hollywood smile was circulated through social media in Saudi Arabia. Statistical analyses of the data obtained were performed using Statistical Package for Social Sciences software (SPSS version 17, USA). Frequencies, percentages, and mean and standard deviation were calculated using descriptive statistics. Pearson chi-squared test was employed to test the association between the demographic variables, such as age, gender, and education levels, with the questionnaire items.

Results:

A total of 4104 participants responded to the study questionnaire. The responses to the questionnaire revealed that nearly half of the participants were not satisfied with their dental appearance (48.6%). The majority of the participants had heard or known about Hollywood smile (98%). About 42% of study participants were aware of the complications involved in the procedure. The results revealed that the younger generation (18 to 30 years) had more awareness and felt more need for dental aesthetics (p=0.001). The proportion of male participants who underwent Hollywood smile correction were more than females (p=0.001). Graduates showed more awareness regarding smile, dental aesthetics, and Hollywood smile than the other categories (p=0.001).

Conclusion:

This study has shown that the younger generation, female participants, and graduates had more awareness regarding smile, dental aesthetics, and Hollywood smile.

Orthodontic Treatment of Bilateral Transposition of Maxillary Canines and Lateral Incisors

Dental transposition is a severe disturbance of tooth position and its eruptive sequence. It may affect any tooth, and it may occur at any location within the dental arch, although some teeth may be more frequently affected than others. There are several types of dental transposition, and their classification depends on the type of teeth involved. The aetiology of transposition is not very clear and has always been the subject of controversies, and it is still not completely understood. The prevalence of dental transposition and the factors related to this dental anomaly have been well documented in the literature. When treating dental transposition, many factors which may affect the treatment results must be considered, such as aesthetics, occlusion, treatment duration, patient comfort, patient cooperation, and periodontal support. Various treatment options are currently available for the treatment of dental transposition. Successful treatment outcomes depend on the patient's age, concern about facial and dental aesthetics, motivation of the patient, functional requirements, type of malocclusion, and the position of the root apices. The present case report is aimed at outlining the orthodontic treatment of a young adult patient diagnosed with bilateral maxillary canine-lateral incisor transposition.

Reasons for widespread aspiration of esthetics veneers “Hollywood Smile”: A survey among five gulf countries

Purpose:

This study aims to assess the factors that determine the aspiration for “Hollywood smile” among the residents in five Gulf countries.

Materials and Methods:

A survey was conducted among subjects aged 18–60 years. A self-designed 19 items questionnaire was prepared which consisted of multiple choices and open-ended questions. The first part of the survey included demographic questions. The second part included questions related to Hollywood smile. Descriptive statistics were calculated, and the association between different variables was assessed by Chi-square test where P ≤ 0.05 was considered statistically significant.

Results:

A total of 2061 subjects participated in the survey. The majority of participants were females (76.81%), 97.28% of them were aware of the term “Hollywood smile,” and social media was the source of information. Statistically significant difference was noted among participants who underwent treatment according to residency place, age, educational level, and socioeconomic status (SES) and participants who were willing to undergo treatment in future according to gender, age, and SES.

Conclusion:

Subjects of younger age, higher education level, and higher SES underwent treatment. However, 23.83% of people were willing to undergo treatment. This reflects the increasing demand for esthetic treatment in future.

Smile attractiveness in class III patients after orthodontic camouflage or orthognathic surgery

OBJECTIVE

The study's objective was to compare the smile attractiveness in patients with class III malocclusion treated with orthodontic camouflage or orthognathic surgery.

MATERIAL AND METHODS

The sample consisted of 30 patients with class III malocclusion treated without extractions divided into two groups, according to the treatment performed: G1, orthodontic camouflage, consisting of 15 patients (9 female; 6 male) with mean initial age of 21.26 years (SD = 7.39) and mean final age of 24.52 years (SD = 7.10). The mean treatment time was 3.26 years (SD = 1.50). G2, ortho-surgical, consisting of 15 patients (8 females; 7 males), with mean initial age of 23.12 years (SD=7.37), mean final age of 25.82 years (SD = 7.14) and mean treatment time of 2.71 years (SD = 0.90). The smile attractiveness was evaluated in black and white photographs of posed smiles taken before and after treatment, with a numerical rating scale from 1 to 10, with 1 being the least attractive and 10 the greatest smile attractiveness. The smiles were evaluated in a questionnaire by 111 participants, 67 orthodontists (mean age 41.31 years, SD = 9.44) and 44 laypeople (mean age 41.41 years, SD = 14.38). Intergroup comparison was performed with independent t test.

RESULTS

There was a significant improvement in the smile attractiveness with both camouflage and ortho-surgical treatments. The smile attractiveness was similar between the camouflage and surgical groups at the beginning. There was a significantly greater improvement in smile attractiveness with treatment in the surgical group than in the camouflage group, and at the end of treatment, the surgical group showed greater smile attractiveness than the camouflage group. Orthodontists considered the smiles more attractive both at the beginning and the end of treatment when compared to the assessment made by laypeople.

CONCLUSION

The ortho-surgical treatment promoted a greater improvement in the smile attractiveness, and at the final stage, a greater smile attractiveness than the orthodontic camouflage.

CLINICAL RELEVANCE

Smile attractiveness is an important characteristic of the final result of orthodontic treatment. Knowing which treatment protocol will provide a better improvement and outcome regarding smile esthetics is essential.

Evaluating upper lip changes during smiling and at rest in Indian population

Context

Smile aesthetics is one of the major goals to be achieved after orthodontic mechanotherapy as it visibly displays the results of orthodontic treatment. Although orthodontic retainers aid in maintaining post-treatment occlusion, soft tissue function and aesthetics, appropriate knowledge of smile changes with age can help orthodontists to obtain stable and aesthetically appealing treatment results.

Aim

To assess and quantify soft tissue changes in the upper lip in vertical dimension at both repose and maximum smiling and to evaluate changes occurring with the smile index and upper lip with age and sex in subjects of Indian origin.

Settings

Department of Orthodontics and Dentofacial Orthopaedics, Army College of Dental Sciences, Secunderabad, Telangana, India.

Design

Observational study.

Methods and Materials

A total of 160 volunteers (80 males and 80 females) selected and were divided into 4 groups according to age and were further divided into 2 sub-groups according to gender. Thirteen measurements of relaxed and smiling upper lip were taken with a calibrated metal ruler and divider directly on the subjects.

Statistical Analysis Used

Analysis of variance (ANOVA) was done followed by post hoc test to determine which groups were significant from others. Levene's test was done to assess equality of variance and t-test for equality of means was done.

Results

Statistically significant results were obtained in between groups and sub-groups for parameters like smile index, upper lip elevation while smiling and smile pattern in males and females changing with increase in age.

Conclusions

High smile patterns with more vertical smile are more common among females and low smile patterns are more common among males. With age, the smile tends to be more horizontal in both genders.

Can Orthodontic Treatment Be Stable 20 Years after the End of the Treatment Scheme? Treatment of a Class 2, Division 1 Malocclusion with Severe Skeletal Discrepancy and Its 20-Year Follow-Up

Class II malocclusions, after class I malocclusions, are the most frequent in the juvenile Italian population. They are most often skeletal in origin and due to mandibular retrusion. Functional devices seem to have a beneficial effect on the growth of the jaw. Long-term maintenance of the achieved results is essential for therapeutic success in any orthodontic treatment; moreover, the retention phase should last as long as possible, especially in the lower anterior sector. A female patient aged 10 years and 3 months presented a visibly convex profile and a severe mandibular retrusion. The anamnesis brought to light the habit of oral breathing and lower-lip sucking. The cephalometric analysis showed a normodivergent skeletal class II. The first treatment phase involved the use of a Bass type for 12 months at the end of the functional treatment; the second phase of fixed therapy was carried out following the principles of bioprogressive techniques. The photos at the end of treatment show an important improvement in the profile; a full class I ratio of molar and canine teeth was achieved with an excellent interarch relationship and a correction of the V-shaped upper arch. The result is occlusally and profilometrically stable after 2, 4, 5, 10, 14, and 20 years. The maintenance of a stable orthodontic result over time is the result not only of a correct and physiological occlusion but also and above all of a correct diagnosis and correct identification of problems that can cause the malocclusion itself. Flawed habits such as interposition of the lower lip and oral breathing must be intercepted and corrected early in order to correct them and not affect the long-term result of orthodontic treatment. In this case, a functional device associated with an orthodontic fixed finishing and a correct retention phase were necessary to correctly treat a second-class mandibular retrusion whose result remained stable 20 years after the end of therapy.

Therapeutic effects of botulinum toxin type A in subjects with gummy smile: A longitudinal sEMG approach

OBJECTIVE

To evaluate the response of the myoelectric activity of levator labii superioris (LLS), levator labii superioris alaeque nasi (LLSAN), and minor zygomatic (Zm) muscles in individuals with gummy smile, volunteers to botulinum toxin type A (BTX-A) application, with a follow-up of 6 months.

MATERIALS AND METHODS

Thirteen individuals were submitted to clinical evaluation and photographic records to monitor the variations of the gingival display (GD) during posed smile. The recording of the surface electromyography (sEMG) signal of muscles studied was performed in three tasks: posed smile (PS), upper lip elevation (ULE) and nose wing elevation (NWE). The root-mean-square value, an amplitude sEMG signal parameter, was extracted from the sEMG signals. One and three-way ANOVA were applied, and the level of significance set at 5%.

RESULTS

There were significant differences (P<0.05) in the sEMG signal activity from the control condition (before BTX-A application - T0) to the 8th week of follow up, which was accompanied by clinical evaluation for the gingival display (P<0.05). The peak of the reduction in sEMG signals occurred 2 weeks after T0 for all the studied tasks, with the exception of the left hemiface in the PS, which showed a peak of reduction 4 weeks after T0.

CONCLUSIONS

BTX-A led to a decrease in the sEMG signal amplitude over 2 to 4 weeks after application in the muscles, although differently concerning each hemiface when recruited to perform other mouth tasks. During the PS, the recruitment level of the upper lip elevator muscles was compatible with the clinical response obtained in the follow-up period in this study, which corroborates the sEMG assessment to clinical data.

Extraction or Nonextraction in Orthodontic Cases: A Review

Orthodontic treatment helps bring teeth in alignment. There is always debate whether tooth should be extracted or not for treating crowding. The present article highlights various advantages and disadvantages of extraction.

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.

Smile Attractiveness Evaluation of Patients Selected for a U.S.-Based Board Certification Examination

Objectives The aims of this study were to assess smile attractiveness of a collection of 68 smiling photographs of successfully treated cases submitted to the American Board of Orthodontics (ABO) clinical examination and identify variables that influence the assessment.

Materials and Methods A panel of 81 non-Caucasian assessors from various clinical disciplines were instructed to score the smile attractiveness on a visual analog scale from 1 (least attractive) to 10 (most attractive) and to select which components contributed to a lesser attractive smile. The mean, standard deviations (SDs), and quartiles of the smile attractiveness were obtained with descriptive statistics. Multilinear regression analysis was performed to investigate the scores of the perceived quality of smile attractiveness when the clinical disciplines and gender of the assessors were the factors taken into consideration. Receiver operating characteristic (ROC) curve was generated to establish the relationship between smile attractiveness and the achievement of a perfect smile.

Results The mean (SD) rating of each clinical photograph of the anterior occlusion on smiling ranged from 3.11 (1.47) as the least attractive smile to 7.59 (1.45) as the most attractive smile. The overall mean (SD) score for smile attractiveness was 5.30 (1.10). Problems associated with teeth, gingiva, and lips corresponded with a reduction of the smile attractiveness score by 1.56, 1.82, and 1.47, respectively. Gender was not associated with smile attractiveness ratings. Orthodontists, periodontists, and prosthodontists demonstrated no difference in the ratings, while plastic surgeons were more critical than orthodontists regarding smile attractiveness.

Conclusions This study suggested that only 2 out of 68 AOB validated treatment finishes had a perfect and attractive 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.

Association of masseter muscles thickness and facial morphology with facial expressions in children

OBJECTIVE

To evaluate the potential influence of muscular capacity and facial morphology on facial expressions in children.

MATERIALS AND METHODS

A cross-sectional study was carried out on 40 healthy children (ages 9-13), without previous orthodontic treatment. Masseter muscle thickness and anthropometric facial proportions were measured using ultrasound and digital calipers respectively. A three-dimensional infrared face-tracking system was used to register facial expressions. The maximal amplitude of smile and lip pucker (representing maximal lateral and medial commissure movement) were used for analysis. Stepwise regression was used to investigate whether muscle thickness or anthropometric facial proportions were associated with the quantity of commissure movement.

RESULTS

When performing maximal smile, children with thicker masseter muscles were found to have more limited displacement of the commissures (R = 0.39; p = 0.036). When performing lip pucker, children with thicker masseter muscles were found to have greater commissure movement (R = 0.40; p = 0.030). No significant associations were found between anthropometric facial proportions and facial expressions.

CONCLUSION

Masseter muscle thickness seems to be associated with facial expressions in children. Those with thicker muscles show more limited commissure movement when smiling, but greater movement with lip pucker. This indicates that masticatory muscles may serve as a surrogate for mimic muscle activity. Facial morphology of the subjects does not seem to be associated with facial expression.

Influence of upper lip curvature on smile attractiveness in patients with different degrees of gingival smiles: A cross-sectional study with opinions from oral health providers and laypersons

INTRODUCTION

Although there is relative consensus about approaches to gingival smile management, there are still discrepancies as to whether a gingival smile is attractive or not. The purpose of this study was to quantify the influence of upper lip curvature shape and the amount of gingival display on the perception of smile attractiveness assessed by Peruvian orthodontists, dentists, and laypersons.

METHODS

A frontal photograph was digitally altered to generate 3 types of upper lip curvature shapes (upward, straight, and downward) with 5 different levels of gingival smile exposure (0 mm, 2 mm, 3 mm, 4 mm, and 5 mm). Fifteen images were generated. Three groups of evaluators (50 dentists, 50 orthodontists, and 50 laypersons) assessed the images using a visual analog scale. One-way analysis of variance with Bonferroni post-hoc tests and multiple linear regressions were applied.

RESULTS

The downward lip curvature shape had a negative effect on the esthetic evaluation of the smile with gingival exposures of 3 mm or more for all the evaluating groups (approximately 20-30 points less than upward or straight smile curvature shapes, P <0.05). Laypeople gave higher scores of almost 10 points more than dentists and orthodontists when evaluating the upward lip curvature shape with 5 mm of gingival exposure during smile (P = 0.029).

CONCLUSIONS

We found that upward or straight upper lip curvature shapes have a positive impact on perceived smile esthetics. In contrast, downward upper lip curvature shapes have a negative effect on perception when evaluating different degrees of gingival smiles.

Smile preferences of orthodontists, general dentists, patients, and the general public in three-quarter and lateral views

INTRODUCTION

This study aimed to analyze differences in esthetic smile preferences between Thai dentists and the general population and determine factors that affect smile perception. For the analysis, in addition to the frontal smile view, the three-quarter and lateral smile views were considered.

METHODS

A computer-based questionnaire was used that comprised a demographic survey and multiple photographs of smiles. In total, 61 orthodontists, 180 general dentists, 378 orthodontic patients, and 421 laypersons were asked to select the most preferred digitally altered smile for each variable in the frontal, three-quarter, and lateral views. Chi-square and Kruskal-Wallis tests with post-hoc tests were used for comparing groups. Multiple linear regression was used to analyze the influence of demographic factors on smile esthetics. Significance was set at P < 0.05.

RESULTS

Chi-square tests revealed significant differences in preference between men and women and between the professional and nonprofessional groups for almost all variables. Demographic factors influenced smile esthetics in the nonprofessional group.

CONCLUSIONS

Both sex and dental knowledge background affected smile preference. The smile preferences of observers varied based on the view, and therefore, the lateral and three-quarter views should be routinely included in smile analyses. Demographics negligibly affected smile perception in the professional group, whereas they significantly affected perceptions in the nonprofessional group, especially age and education.

The Influence of Age and Facial Expression (Eye Open/Closed) On Maxillary Dental and Gingival Display

PURPOSE

To assess if there are any differences in maxillary dentogingival exposure between different facial expressions (maximum smile with eyes open and eyes closed), age groups and both sexes.

MATERIAL AND METHODS

Digital photographs of the lower third of the face of 120 subjects, belonging to 6 different age groups were taken. There were 20 subjects in each of the 6 age groups (20-30, 30-40, 40-50, 50-60, 60-70, and 70-80) which were comprised of 80 women and 40 men. Two standardized images of each subject were taken, one of maximum smile with eyes open, and the second of maximum smile with eyes closed. These 240 images were used to quantify a dentogingival exposure ratio (DER) for each tooth spanning the second bicuspids on either side, using standardized measurement techniques. Additionally, incidence of interdental papilla visibility was studied in a binary manner, and all data were studied with respect to various covariables of age, sex and type of facial expression using a generalized linear mixed effects model. A p-value < 0.05 was determined to be statistically significant.

RESULTS

There was a statistically significant difference between the dentogingival exposure ratio (DER) for all images with eyes open and eyes closed per tooth location studied, across all age groups (p ≤ 0.001) and both sexes, suggesting that subject images of smiles with eyes closed had significantly higher dentogingival exposure. There was a decreasing trend of DER with increasing age groups when eyes were open (p = 0.005) and when eyes were closed (p = 0.042), suggesting that older subjects had lower dentogingival exposure. With respect to sex, there was no statistically significant difference in mean DER between males and females, when eyes were open (p = 0.430) and closed (p = 0.351). The incidence of interdental papilla exposure also differed significantly between images with eyes open and eyes closed across all age groups (p ≤ 0.001). However, the incidence of interdental papilla exposure decreased with age, only in images with eyes open (p < 0.001) but was not statistically significant among images with eyes closed (p = 0.127). With respect to sex, there was a significant difference in incidence of interdental papilla exposure in images with eyes open (p = 0.029) but no significant difference when eyes were closed (p = 0.782).

CONCLUSIONS

Maxillary dentogingival exposure decreases with increasing age and is significantly higher when recording maximum smile with eyes closed, for all age groups and both sexes. As this is a simple and clinically reproducible facial expression, incorporating patient's maximum smiling images with eyes closed may be routinely necessary for complete and accurate data collection for prosthodontic treatment planning purposes.

Nonsurgical treatment of an adult with skeletal Class III malocclusion, anterior crossbite, and an impacted canine

Class III malocclusion presents some complexity in terms of diagnosis and treatment and affects not only the jaws but the whole craniofacial complex. Besides, functional forward displacement of the mandible may be diagnosed in a patient presenting Class III malocclusion, as the 2 entities are not incompatible or mutually exclusive. This case report describes the multidisciplinary, nonsurgical, orthodontic treatment of an adult patient with a skeletal Class III malocclusion, anterior crossbite, and a palatally impacted canine, treated with fixed appliances and skeletal anchorage. To upright the mandibular molars, distalize the whole mandibular arch, and avoid excessive inclination of maxillary incisors to improve dentofacial esthetics, miniscrews were placed in the retromolar area. The treatment results were very satisfactory and remained stable after a reasonable retention period.

Perception of Smile Aesthetics of Patients with Anterior Malocclusions and Lips Influence: A Comparison of Dental Professionals’, Dental Students,’ and Laypersons’ Opinions

Objectives. The aim of the study was to evaluate the perception of smile aesthetics in patients with varying degrees of anterior crowding and spacing among dental specialists, dentists, dental students, and laypersons and to assess the effect of the lips position. Materials and Methods. Clinical photos of cases of anterior crowding (mild, moderate, and severe) and spacing (mild, moderate, and severe) with and without the associated lips were used. The images were evaluated by 250 persons including dental specialists, dentists, dental students, and laypersons using the rating scale method, (extremely unaesthetic to extremely aesthetic, 1 to 5, respectively). Nonparametric tests were used to analyse the data on SPSS version 24. Results. According to the 250 responses, the aesthetic perception of all severities of anterior crowding and mild and moderate spacing was found to be more aesthetic when displayed with the lips ( $p<0.05$ ). Additionally, the higher the level of dental education, the lower the aesthetic perception with and without the lips ( $p<0.05$ ). Conclusions. The lips play a significant role in improving the aesthetics of crowded anterior teeth and spaced anterior teeth. Dental educational level influences the aesthetic perception of anterior crowding and spacing. This may have an impact on treatment planning and need for orthodontic intervention.

A Communication Guide for Orthodontic-Restorative Collaborations: Digital Smile Design Outline Tool

Ideally, Orthodontic-Restorative cases are planned alongside from the beginning, however, in some instances the restorative dentist encounters the patient for esthetic evaluation near the end of orthodontic phase. This is a high-stakes evaluation because the decision to remove brackets implies that refinement of tooth positioning cannot occur unless the patient re-enters orthodontic treatment. One challenge in multidisciplinary treatment is accommodating effective communication between providers and employing Digital Smile Design outline tool as a visual aid can help optimizing treatment outcome. This article discusses the importance and steps utilizing digital outline tool to provide quick and effective communication on treatment progress and recommendations.

The relationship between dentofacial morphology and smile characteristics in lateral and oblique views

Background/purpose

The purposes of this study were to develop smile measurements for lateral and oblique view photographs to help in orthodontic analysis and treatment planning, to quantitatively evaluate the relationship between smile esthetics and different types of malocclusion using lateral and oblique view photographs, to identify the cephalometric factors affecting smile measurements.

Materials and methods

Patients who came to orthodontic department of a university hospital from 2014 to 2017 and met the inclusion criteria were included and divided into three groups according to Angle's classification. Thirteen variables were measured for cephalometric analysis. Twenty-one variables were developed and measured on pretreatment photographs for lateral and oblique smile analysis. ANOVA and Scheffe post hoc test were used to compare cephalometric and smile variables among three groups. Multiple linear regression analysis was performed to identify cephalometric factors affecting smile measurements.

Results

Three-hundred and ninety patients (287 females, 103 males) with mean age of 24.5 ± 7.6 years reached the criteria. All cephalometric variables differed significantly among three groups. Except for maxillary teeth exposure number, visible maxillary width, and lip thickness ratio, all smile variables differed significantly. Smile characteristics had significant correlation with some cephalometric measurements.

Conclusion

Smile patterns on the lateral and oblique view photographs can be affected by different types of malocclusion. Therefore, we suggest to include lateral and oblique smile view photographs in the data collection for orthodontic treatment planning.

Miniscrew mechanics for molar distalization and incisor intrusion in a patient with a Class II brachyfacial pattern and gummy smile

A gummy smile is one of the most problematic characteristics in patients with a Class II Division 2 malocclusion, and the correction of vertical position and incisor torque is often challenging for the orthodontist. This case report describes the orthodontic treatment of a 31-year-old woman, assisted by miniscrew mechanics for maxillary arch distalization and correction of a gummy smile with a brachyfacial pattern. Two different mechanics were used. Miniscrews were placed in both maxillary tuberosities, and the maxillary arch was successfully distalized, correcting the Class II relationship. Interradicular miniscrews were placed for maxillary and mandibular incisor intrusion to correct the gummy smile, overbite, and torque. Finally, periodontal surgery was performed to lengthen the maxillary incisor crowns. Satisfactory smile esthetics and good occlusion were achieved. Follow-up after 24 months confirmed that the outcome was stable.