Effects of buccal corridors on smile esthetics in Japanese and Korean orthodontists and orthodontic patients

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.

Customized planning of the visible maxillary arch width in harmony with interparopia width and smile width for female facial aesthetics

BACKGROUND

The visible maxillary arch width (VAW) is an important aesthetic-determining feature. To date, there is no well-established methodology to determine the aesthetically optimal VAW in customized treatment planning.

METHODS

In this study, the common traits of the dentofacial configuration were investigated in most attractive Asian and Caucasian female smiles. The smiling photo of a subject was digitally modified based on combined variations of VAW, smile width (SW), transverse facial dimensions (TFD), and vertical facial dimensions. These modified photos were assessed for aesthetics. The aesthetically essential parameters were identified, and their mathematic correlations and reference ranges were determined for different vertical facial patterns. Using the obtained results, a mathematic guidance was constructed for customized smile designing. The applicability of this guidance was tested in Asian females.

RESULTS

The most attractive Asian and Caucasian female smiles have intraracial and interracial commonalities in the VAW-to-TFD ratios. The interparopia width (IPD) predominated over facial widths in determining well-matched VAW and SW. For optimal smile aesthetics, the VAW and SW were correlated as simulated by the formula 1.92 IPD ≤ VAW + 2.3 SW ≤ 2.17 IPD, plus the VAW-to-IPD ratio within 0.54 to 0.62 and the SW-to-IPD ratio within 0.61 to 0.71, ranges tailored to vertical facial patterns. This constitutes a mathematic guidance for customized planning of the aesthetically optimal VAW. This guidance was preliminarily validated to be applicable to Asian females.

CONCLUSIONS

The VAW-to-TFD ratios were essential for Caucasian and Asian female smile aesthetics. The mathematic guidance could serve as a reference for customized smile designs for Asian females.

PM, Sundareswaran S, Parayaruthottam P, Jisha B. Orthodontic urgencies and their management during COVID-19 pandemic-A web-based survey

OBJECTIVES

This investigation aimed to evaluate the most common orthodontic urgencies, their management, and changes in routine biosafety measures and the total income of the dental office in South India during the COVID-19 pandemic.

METHODS

A questionnaire was drafted using Google Forms with questions in four domains pertaining to orthodontic urgencies, biosafety measures, treatment duration, and income. After validation, this questionnairewas sent to 750 orthodontists via WhatsApp messenger (WhatsApp Inc, Menlo Park, Calif) over a period of 14 days.Descriptive statistics and comparisons were performed using independent t- and Chi-square tests.

RESULTS

Majority of the orthodontists (62.3%) had closed their clinics only during the first lockdown. Many (63%) had scheduled urgent appointments along with routine limited patients per day. The most frequent urgencies were related to the breakage of brackets, archwires, molar tubes, bands, and temporary anchorage devices. Aligners were the least problematic. The treatment time was also prolonged. Telephonic advice and virtual assistance via WhatsApp messages/videos were found to be successful in the management of urgencies.Most orthodontists had strengthened their routine biosafety measures.The financial impact of this pandemic was considerable, with nearly 50% reduction in total income.

CONCLUSIONS

Urgencies linked to preadjusted edgewise appliances, such as breakage of brackets and tubes, and archwire-related injuries were the most common. Prolongation of treatment time and negative financial impact were the other problems encountered during this pandemic. Drastic changes had occurred in routine biosafety measures, which prevented the spread of infection among orthodontists and patients.

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.

Effect of the ethnic, profession, gender, and social background on the perception of upper dental midline deviations in smile esthetics by Chinese and Black raters

BACKGROUND

The purpose of this study was to compare the perception of upper dental midline deviation on the attractiveness of a smile among raters from different ethnicities, professions, genders, and ages and measure to what extent the presence or absence of the associated smiling structures influence the raters' evaluations.

METHODS

A male subject (26 years of age) with adequate smile characteristics was selected by 3 experienced orthodontists, and 561 raters from 2 different ethnic groups (281 Chinese raters and 280 Black raters) rated the subject's smile after the subject's upper dental midline was digitally altered from 0 to 5 mm using a 5-point Likert scale on 12 smile photographs divided into two groups: group 1, in the presence of smile related structures, two-thirds of the nose, lips, and chin (NLC), and group 2, in the absence of smile related structures, the lips only (L).

RESULTS

There were statistically significant differences (p < 0.05) between the two ethnicities, in 2 mm and 4 mm in-group NLC and 5 mm in-group L, as well as the raters' profession to each midline shift of both groups (NLC) and (L) for both ethnicities except for 0 mm. Regarding the role of associated smile structures, the smile photos were observed in the presence of smile-associated structures, and in its absence (NLC × L), statistically significant differences (p < 0.05) were found when the deviation was 5 mm among the Chinese raters; in 1 mm, and 4 mm among the Black raters. Among different genders, statistical differences were only reported (p < 0.05) for Chinese raters for 5 mm in NLC, while statistical differences were observed for 2 mm and 3 mm in NLC for Black raters. For age categories, differences were observed (p < 0.05) for 4 mm, 5 mm in NLC and 4 mm, and 5 mm in L for Chinese raters, while 5 mm in NLC and 1 mm in L for Black raters.

CONCLUSION

Perception of the upper dental midline deviations was influenced by the factors of ethnicity, profession, presence or absence of smile-associated structures, as well as the gender and age of the raters.

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 Esthetics of the Nasolabial Fold and Age in the Elderly Via Eye-Tracking

Background

Facial aging is associated with the loss of soft tissue fullness. Perioral signs of facial aging can add years to individuals' appearances and even affect their facial expressions in smiling and nonsmiling images.

Aims

To evaluate the influence of the nasolabial fold on the visual perception of esthetics and age in the elderly, eye-tracking and a visual analog scale were used.

Material and Methods

This study applied a cross-sectional study using 40 laypeople. Facial images of an elderly woman were modified to include facial expression lines such as nasolabial folds and marionette lines with no folds, intermediate, and accentuated depths folds. Eye tracking was implemented to measure the average number of fixations. Heat maps and dot maps were generated using eye-tracking software. A visual analog scale of attractiveness and age perception questionnaire were also incorporated into the study. Statistical analysis was performed using a significance of (P<0.05).

Results

The majority of visual attention was paid to the eye and mouth areas. In the images with no folds, the right eye attracted a greater degree of fixation. In the images in which nasolabial folds were accentuated, the mouth area served as an area of high fixation. No statistical difference was observed between the groups in which smiling images were viewed. Nonsmiling images demonstrated significant differences between groups for variables including time until first fixation, complete fixation time, and number of fixations on the eyes and hemifaces. Old age and diminished attractiveness were associated with attenuated nasolabial folds, especially in nonsmiling images.

Conclusion

The facial lines and expressions of elderly female individuals were assessed by laypeople using eye-tracking, showing that the deeper one's nasolabial folds, the more aged and less attractive one appears, especially in nonsmiling images. Smiling pictures were perceived to be more attractive and youthful; these perceptions should be considered in the search for improved esthetic results, whether in dental or facial esthetic treatments.

Golden Mean and Proportion in Dental Esthetics after Orthodontic Treatments: An In Vivo Study

PURPOSE

The definition of the golden ratio was established around the sixth century BC; Levin and Snow developed specific theories applicable in dentistry, which apply the golden proportion rule with the intention of reproducing a perfect smile. This study analyzed the literature and assessed whether these concepts remain valid and applicable in clinical practice, evaluating the theories with a group of patients followed by an experienced orthodontic team.

METHODS

This study was retrospectively performed on 400 patients (241 females and 159 males) who underwent orthodontic treatments. The analysis was conducted on intraoral frontal photos, both pre-treatment and post-orthodontic treatment, to observe if there was a statistically significant difference in the tooth display according to the golden mean and golden proportion theories.

RESULTS

The canine at the end of the orthodontic treatment had a greater visibility than that proposed by Levin and Snow.

CONCLUSIONS

This study revealed how these theories could be considered in certain respects, but nowadays are not totally valid and applicable to the clinical reality. Snow's theory appears to be more consistent with the clinical findings than Levin's theory.

Social attractiveness perception of a cleft lip repair in an adolescent via eye-tracking

PURPOSE

The present study was designed to investigate the perception of unilateral cleft lip (UCL) repair scar using an image of an adolescent and eye-tracking technology.

MATERIAL AND METHODS

Frontal and oblique views of an image of an adolescent with a unilateral upper lip scar result of a corrective surgery. Eighty-five laypeople respondents were divided into three groups: Group A (15-44 years of age); Group B (45-59 years of age); and Group C (≥ 60 years of age). Gaze tracking was carried out to assess the location on the image of greatest fixation, to create dot maps and to follow the trajectory of the gaze. Respondents also assessed six attention questionnaires. The answers and assessment of the VAS were compared. P-values &lt;0.05 were considered significant in the analyses.

RESULTS

The central focus of the visualization was concentrated on the upper lip and the region of the nostril, followed by the eyes. Time until 1st fixation upon right lip and mouth showed differences with regard to different images. Images of the model shown in various guises including smiling or not, in a frontal or oblique views showed significant differences in VAS scoring (p&lt;0.001).

CONCLUSION

The presence of a scar from the UCL repair in an adolescent was noted in the foreground by laypeople. The scar was associated with a lower degree of attractiveness, happiness, and intelligence, as well as with shyness and sympathy, although a visible scar did not influence the perception of "good hygiene habits".

The Influence of the Maxillary Posterior Region on Smile Aesthetics in a Chinese Cohort

OBJECTIVES

The aim of this research was to establish standard norms for posterior smile-related characteristics including posterior smile line (PSL), the most posterior teeth displayed, buccal corridor ratio (BCR), and buccal corridor symmetry (BCS) and investigate its aesthetic contributions to smile attractiveness in a Chinese population.

MATERIALS AND METHODS

From digitally recorded dynamic smile videos of young Chinese participants, 188 standardised full-smile images were captured and then aesthetically evaluated by 22 laypersons using a visual analog scale (VAS). Four smile-related variables in the posterior region were analysed. VAS data were compared between subgroups to test the influence of these variables on smile aesthetics with significance level of P < .05.

RESULTS

The VAS scores of participants with high PSL were significantly lower than those with average or low PSL (P < .01), especially when they display average or low anterior smile line (P < .05). Smiles with the second premolar displayed obtained the highest VAS amongst the 3 subgroups (P < .05). No significant differences were found between the VAS scores of BCR and BCS (P > .05).

CONCLUSIONS

Maxillary posterior gingiva and teeth displayed influence smile attractiveness evaluated by laypersons, which should be given attention when treating patients with compromised aesthetics, especially those displaying average or low anterior smile lines.

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

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

The influence of malocclusion on social aspects in adults: study via eye tracking technology and questionnaire

BACKGROUND

Smile esthetics has a strong influence on perception, attractiveness, and personal characteristics. It is unknown how malocclusions may influence the appearance of the individual's smile. This study aimed to investigate whether malocclusion affects the visual perception of esthetics, age, employability, honesty, intelligence and to meet its obligation in time in middle-aged adults. Facial frontal smiling photographs of a male and a female middle-aged adult with 3 different malocclusions were shown to and evaluated by 90 laypeople (non-dentists), divided into groups: young adults (14-44 years), middle-aged adults (45-59 years), and elders (over 60 years). The index of treatment need (IOTN) was used, and IOTN 1, 5, and 8 images were created in Photoshop using the male and female photographs. In total, 6 photographs were evaluated, 3 areas of interest (AOI)-eyes, nose, and mouth-were created for statistical comparison. The Ogama and Eye Tribe tracker were used in conjunction to measure eye tracking. A visual analog scale (VAS) was employed with a questionnaire surveying individuals' perception of age, employability, honesty, intelligence, and ability to meet obligations. Kruskal-Wallis, one-way analysis of variance, Pearson's-chi-squared, and Pearson correlation test were applied.

RESULTS

No statistical difference was found in complete fixation time and time until the first fixation for each AOI for eye-tracking. VAS showed statistical differences in the male and female IOTN 1 images when compared with the IOTN 5 and 8 for both models, and there was no difference between genders in the IOTN 1. As the perceived age of the model increased, the chances of getting hired decreased. Employability, honesty, intelligence, and ability to meet obligations showed higher values for IOTN 1. There were significant differences between age ranges; perception of intelligence in the female IOTN 1 model (p = 0.002) and IOTN 8 model (p < 0.001) and honesty between young adults and middle-aged adults in the male IOTN 1 and 8 images (p < 0.001).

CONCLUSIONS

There was a difference between age groups in the perception of honesty and intelligence. A well-balanced and attractive was perceived as more youthful and attractive in both genders and may increase the chance of being selected for a job interview or being hired.

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.

Perceptions of orthodontists, laypersons, and patients regarding buccal corridors and facial types

INTRODUCTION

The space on each side of the mouth, between the commissure of the mouth and the buccal surface of the last visible tooth, is called the buccal corridor. The size of the buccal corridor can affect perceptions of facial esthetics. We analyzed the perceptions of orthodontists, laypersons, and orthodontic patients regarding the size of buccal corridors in people with brachyfacial, mesofacial, and dolichofacial types.

METHODS

Photographs of 1 male and 1 female model were modified digitally into brachyfacial, mesofacial, and dolichofacial types. Each facial type was further modified to create 5 sizes of buccal corridors. Orthodontists, adult orthodontic patients, and laypersons were invited to rate the photographs.

RESULTS

Orthodontists rated lower than the other groups of raters when they evaluated the female model with the buccal corridors of 20% (P <0.05). Laypersons could not distinguish the changes of the buccal corridors when evaluating the male model with brachyfacial and mesofacial (P >0.05). Orthodontic patients rated significantly higher than the orthodontists and the laypersons when evaluating the dolichofacial type of both models (P <0.05).

CONCLUSIONS

Orthodontists are more sensitive to the buccal corridors than are orthodontic patients and laypersons. It is only necessary to consider eliminating the patient's buccal corridors when the buccal corridor area ratio is over 15%.

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.

Evaluation of the perception of smile esthetics, in frontal view, with mandibular laterognatism, through the eye-tracking technique

OBJECTIVES

To evaluate the perception of esthetics and the attractiveness of the smile, in frontal view, with mandibular asymmetry, through the eye-tracking.

MATERIALS AND METHODS

OGAMA software and The Eye Tribe Tracker hardware were used to obtain eye tracking in certain areas of interest on the face. To simulate asymmetry, Photoshop® image editing software was used to create a vertical reference line to the midline of the face and make it symmetrical with control of the angulation relative to another horizontal reference line passing through the vertices. Then, the lower third of the face added asymmetries or deviations, starting from zero, with increments of 2 by 2 degrees up to 6 degrees. The study included 60 laypeople, 30 males and 30 females, without any knowledge about the study, showing good vision, and not having used drugs with the possibility of influencing cognitive or motor skills.

RESULTS

From the heat map in cases of mandibular asymmetry, it is possible to visualize that for both sexes the evaluators evaluated with a certain degree of similarity mainly when the deviations presented with 6 degrees. The trajectory of the male and female gaze in cases with asymmetry shows that in cases with a magnitude of 6 degrees, the raters traced mainly in the region of the mouth with little transition in the eye region and mainly in the areas of interest considered as "other." In the images presented with a magnitude of up to 4 degrees, they were traced in the general image.

CONCLUSIONS

The perception of laypeople from mandibular asymmetry to the right in females presented a higher perception when compared to males with mandible asymmetry to the left.

Thresholds of Abnormality Perception in Facial Esthetics among Laypersons and Dental Professionals: Frontal Esthetics

Aim

To find thresholds at which laypersons and dental professionals perceive abnormalities in two facial frontal esthetics variables: facial symmetry and vertical harmony.

Materials and Methods

A baseline frontal image of a young male face with optimum facial proportions was generated from a real image using a photo editing software. Different facial asymmetry images were then generated from this image by manipulating the chin point position at 2 mm increment to the left side. Vertical harmony was perceived through manipulating lower anterior facial height (LAFH) at a ratio of 2% of increased and decreased heights. A total of 120 raters divided equally into four groups of laypersons, general dental practitioners (GDPs), orthodontists, and oral and maxillofacial surgeons (OMFSs) rated these images using an analog scale of 100 mm long. Using ANOVA and Tukey post hoc tests at P < 0.05, the image that showed the first statistical difference compared to the baseline was considered as a threshold of abnormality.

Results

The image of 4 mm asymmetry was defined by the laypersons and GDPs as the threshold of abnormality, while the orthodontists and OMFSs realized that at 2 mm. Laypersons and GDPs defined a threshold of 46% as an abnormal decrease in the LAFH and the other 2 groups at 48%. All dental professionals groups rated the image of 54% as an abnormal increase in the LAFH while laypersons perceived that at 56%.

Conclusion

These thresholds regarding frontal esthetics may contribute to the process of establishing proper orthodontic treatment planning that suits the highest facial esthetic standards.

Urgencies and emergencies in orthodontics during the coronavirus disease 2019 pandemic: Brazilian orthodontists' experience

Introduction

The present study aimed to evaluate the most common urgencies and emergencies in orthodontics during the coronavirus disease 2019 (COVID-19) pandemic and to assess how orthodontists in Brazil were dealing with patients and challenges.

Methods

Early in 2020, as the COVID-19 pandemic spread around the world, routine dental care was suspended in many countries, and only patients needing urgent or emergency care could be seen. During this period, orthodontists in Brazil were invited to participate in an anonymous online survey. Over 48 hours (May 1-3, 2020), 395 orthodontists (specialists, MScs, and PhDs) responded. They answered questions regarding dental office and appointments during the pandemic, the type of urgency or emergency care provided, the type of appliance and urgencies, etc. The level of concern about the impact of the pandemic on patients' orthodontic treatments and the financial impact on the dental office was also evaluated. Descriptive statistics were performed with percentages, and responses were compared between specialists, MScs, and PhDs, using chi-square tests.

Results

Specialists were the majority of respondents. Most orthodontists were handling only emergencies or urgencies. The most frequent urgencies were bracket breakage, archwire breakage, and breakage of molar tubes and/or bands. Stainless steel fixed appliances were the most common type of appliance related to unscheduled appointments. The majority of patients got in touch with the orthodontist using the professional WhatsApp messenger (WhatsApp Inc, Menlo Park, Calif). Orthodontists were more concerned with the financial impact of the pandemic than with the orthodontic treatment itself.

Conclusions

Breakage of brackets, archwires, or tubes and/or bands were the most common causes of urgency and/or emergency appointments during the pandemic. The level of concern about the financial impact of the stay-at-home orders and the COVID-19 pandemic was significantly greater for specialists and MScs than for PhDs.

•

We surveyed orthodontists in Brazil during the coronavirus disease 2019 pandemic.

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Most frequent urgencies were breakages of brackets, archwires, molar tubes, or bands.

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Stainless steel fixed appliances were the type most related to unscheduled appointments.

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Most patients contacted the orthodontist using the professional WhatsApp messenger.

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Orthodontic specialists and MScs were more concerned than PhDs about financial impacts.

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.

Comparison of smile esthetics among celebrities, dentists, and dental students in a Han Chinese population

STATEMENT OF PROBLEM

Various components of smile esthetics have been evaluated. However, whether these components affect smile esthetics in Han Chinese celebrities, dentists, and dental students is unknown.

PURPOSE

The purpose of this study was to evaluate the smile esthetics of celebrities, dentists, and dental students in a Han Chinese population.

MATERIAL AND METHODS

Frontal images of smiles were obtained from the Internet for the celebrity group, while images of dentists and dental students were collected for the dentist and dental student groups. The buccal and posterior corridor ratios, the alignment discrepancy between the commissural and interpupillary lines, the number of teeth revealed, the width ratio relative to the golden proportion, and the width-to-length ratios of maxillary anterior teeth were calculated by using a photo-editing software program. Statistical analysis was performed by using 2-way ANOVA and the Tukey HSD test (α=.05).

RESULTS

Eligible images were obtained for 81 celebrities, 83 dentists, and 78 dental students. The celebrities were found to have the highest buccal and posterior corridor ratios and reveal the least teeth in the smile among the 3 groups (all P<.001). The alignment discrepancy for celebrities was significantly less than that for dental students (P=.025). Moreover, the absolute difference of width ratios from the golden proportion was significantly different from 0 for all groups (all P<.001).

CONCLUSIONS

Significant differences were found in the smiles of Han Chinese celebrities, dentists, and dental students in regard to the buccal and posterior corridor ratios, the alignment discrepancy between the commissural and interpupillary lines, and the number of teeth revealed. Chinese celebrities tended to have a smile that displays to the second premolar, with a medium buccal corridor width.

Perception of general dentists and laypersons towards altered smile aesthetics

OBJECTIVES:

This study aimed to evaluate how dental practitioners and laypersons differ in their perception of altered smile aesthetics based on viewing images of a digitally manipulated smile.

MATERIALS AND METHODS:

A photograph with close to ideal smile characteristics was selected and digitally manipulated to create changes in buccal corridor space (BCS), midline diastema, gingival display, and midline shift. These altered images were rated by two groups: dental practitioners and lay persons using a visual analogue scale. The mean ± standard deviation (SD) of both groups were calculated and the Student's t-test was used to identify any statistically significant differences between the groups. Data analysis was done using the Statistical Package for Social Science (version 23.0; SPSS Inc., Chicago, Illinois, USA).

RESULTS:

The dentists were more sensitive to changes in the midline shift than laypeople and provided lower scores. There were no significant differences between the two groups when the gingival display alteration was ≤3 mm. However, for gingival display of 4 mm and 5 mm, there was significant difference between the two groups, with dentist rating them poorer as compared with the laypeople (P < 0.001). Dentists were more sensitive than the laypeople for midline diastema of 2 mm and 3 mm (P < 0.001 and P = 0.005 respectively). Changes in the BCS had minimal impact on the overall esthetic score for both the groups.

CONCLUSIONS:

Perception of smile esthetics differed between dentists and laypersons.

The Influence of the Smile on the Perceived Facial Type Esthetics

Objective

The objective of this study was to determine if the smile would influence the facial types esthetics perception for dentists, specialists, and laypeople. The null hypotheses for this study were that the smile has no effect on the perceived facial esthetics of different facial types.

Materials and Method

A photograph of an attractive female face with an attractive smile was captured and manipulated using computer software, which was used to produce changes in the smile and facial type of the female face. Two sets of photographs were developed. The first set is composed of three photos showing mesofacial, dolichofacial, and brachyfacial faces; on these photos the smiles were masked intentionally. On the second set, the smile was revealed in the three face types (mesofacial, dolichofacial, and brachyfacial faces); this results in three smiling photos, where each showed a facial type with the same smile. These photos (6 photos in total) were rated by the participants; two hundred participants were recruited, 50 general dentists, 50 specialist dentists, and 100 laypeople.

Results

The three groups (dentists, specialists, and laypeople) rated the mesofacial face as the highest (p value < 0.01) (64.48, 76.12, and 60.68, respectively), the mesofacial face was the only face that showed a significant difference between the three groups ratings (p value<0.01), and this significant difference disappeared when we compared the smiling photos for the mesofacial face (p value>0.01).

Conclusion

Mesofacial face is considered to be the most attractive face in comparison to dolichofacial and brachyfacial faces. Facial type should not be looked at separately from the smile as the smile might influence the esthetics perception of the facial type.

An evaluation of the influence of teeth and the labial soft tissues on the perceived aesthetics of a smile

Objective The aim of this study was to investigate how the lips and teeth may affect the perceived aesthetics of a given smile. Lips and teeth were collectively assessed in different fields of view to see how they may contribute to smile aesthetics. The perception of 'beauty' was assessed to determine whether differences existed between; dentists, non-dentists, males and females.Methods Five subjects were photographed to produce the following views: 1) retracted anterior teeth; 2) lips at rest; 3) zoomed smile; and 4) smile showing the lower face. Images were compiled in a survey questionnaire and shown to respondents who ranked the subjects in order of aesthetic appeal. Kendall's coefficient of concordance (W) and median rank scores were used to determine the statistical significance.Results All groups demonstrated statistically significant agreement in the perception of beauty. Both the teeth and lips seemed to contribute similarly to the attractiveness of a smile. Dentists seemed to be more influenced by teeth in a zoomed smile view, however, this was negated when viewing a broader field of view. All other groups showed no difference in perception of aesthetics with changing field of view.Conclusion Both lips and teeth seem to contribute to the aesthetic appeal of a smile. Dentists may have a tendency to place a disproportionate weight to teeth when assessing a smile close up.

Smile esthetics: Evaluation of long-term changes in the transverse dimension

Objective

To analyze the long-term changes in maxillary arch widths and buccal corridor ratios in orthodontic patients treated with and without premolar extractions.

Methods

The study included 53 patients who were divided into the extraction (n = 28) and nonextraction (n = 25) groups. These patients had complete orthodontic records from the pretreatment (T1), posttreatment (T2), and postretention (T3) periods. Their mean retention and postretention times were 4 years 2 months and 17 years 8 months, respectively. Dental models and smiling photographs from all three periods were digitized to compare the changes in three dental arch width measurements and three buccal corridor ratios over time between the extraction and nonextraction groups. Data were analyzed using analysis of variance tests. Post-hoc multiple comparisons were made using Bonferroni correction.

Results

Soft-tissue extension during smiling increased with age in both groups. The maximum dental width to smile width ratio (MDW/SW) also showed a favorable increase with treatment in both groups (p < 0.05), and remained virtually stable at T3 (p > 0.05). According to the MDW/SW ratio, the mean difference in the buccal corridor space of the two groups was 2.4 ± 0.2% at T3. Additionally, no significant group × time interaction was found for any of the buccal corridor ratios studied.

Conclusions

Premolar extractions did not negatively affect transverse maxillary arch widths and buccal corridor ratios. The long-term outcome of orthodontic treatment was comparable between the study groups.

Assessment of esthetic characteristics of the teeth and surrounding anatomical structures

PURPOSE

To determine the differences in the perception of aesthetic characteristics of the front teeth which include anatomic variations, appearance of the gums and dental arches, smiles and the lower third of the face between three groups of assessors.

MATERIALS AND METHODS

The study included 60 patients with permanent fully toothed dentition with no prosthetic work done and with Angle class I, whose lower third of the face was photographed while smiling. Collected photos were then assessed by people of the general population (21), graduate doctors of dental medicine (20) and specialists in dental prosthetics (20) using a modified OAS questionnaire (Orofacial aesthetic scale).

RESULTS

General population assessors gave weakest scores to the appearance of teeth, tooth color and appearance of the dental arches, and they gave highest scores to the appearance of the gums. Specialists in dental prosthetics gave top scores (p <0.01) for the shape and color of teeth, the appearance of the dental arches and lips and general appearance of the lower third of the face, and gave the worst scores for the appearance of the gums (p <0.01). Male assessors and people aged 36-55 are the least critical in assessing the shape and the color of teeth, appearance of the arches and lips, and the general appearance of the lower third of the face. In assessing the gums the most tolerant assessors are patients over the age of 55 (p<0.01).

CONCLUSION

Considering the age and gender it can be concluded that all the criteria contribute to the assessment of the aesthetics of the teeth and surrounding structures. The results of this study may help in the planning of dental prosthetics procedures.

Total intrusion and distalization of the maxillary arch to improve smile esthetics

This case report illustrates the successful treatment of a patient with skeletal Class II malocclusion and an unesthetic smile involving excessive gingival display and large buccal corridors. By applying dual buccal interradicular miniscrews, total intrusion of the maxillary dentition along with distalization was induced to improve both the occlusion and smile esthetics. In addition to the conventional cephalometric superimposition, three-dimensional superimposition was performed and evaluated to validate the treatment outcome.

Buccal Corridors: A Fact or a Myth in the Eyes of Laymen?

AIM:

This study aimed to investigate laymen knowledge of the existence of the buccal corridor and whether it was an important factor for them in judging smile attractiveness and the effect of introducing the knowledge to them on their further judgment.

MATERIALS AND METHODS:

Nine subjects were randomly selected with variable buccal corridor percentages. They were coached to smile in a posed fashion and full face smile photographs were taken from a standardised distance. The photographs were randomly arranged in a power point presentation and displayed to a panel of thirty-nine randomly selected laymen judges. The judges made their beauty judgment on a visual analogue scale (VAS) and filled a questionnaire. After their education about the buccal corridor, they were asked to make a second judgment on a second sheet with VAS and with a different random sequence of the photographs.

RESULTS:

Intra-class correlation agreement for all the judges between the first and second scores was 0.713. The Spearman’s rho Correlation coefficient indicated a positive correlation for all the photos. For the male judges, the agreement between the ratings was 0.839, and the correlation was positive for all the photos. For the female judges, the agreement between the ratings was 0.510, and the correlation was positive for all the photographs. Hundred percent of the judges were not familiar with the buccal corridor. Eighty percent of the female judges and 44.4% of the male judges mentioned that it would affect their further judgment.

CONCLUSION:

Laymen build their esthetic judgments on what we teach them, and modifying treatment plans to include corrections of buccal corridors for esthetic reasons only is a myth.

Perceptions of Altered Smile Esthetics: A Comparative Evaluation in Orthodontists, Dentists, and Laypersons

Objective. The current investigation was proposed to determine the impression of trained dental professionals and laypeople towards the modified smile esthetics. Materials and Methods. Twenty-six images were randomized in a survey and graded according to attractiveness by the orthodontists, general dentists, and laypeople. Photographs of gingival display, midline diastema, central incisor crown length, and lateral incisor crown width were manipulated with five minor changes in each. For smile arc and buccal corridor, two major changes were incorporated besides the ideal photograph. One-way ANOVA and Post Hoc analysis of the responses were measured for each group. Results. Most evaluators opined that the ideal smile in each category was the most acceptable. Orthodontists were more perceptive and exacting in accepting variations in the smile arc and buccal corridors. Dental professionals and laypeople indicated that either complete absence or a 0.5 mm of alterations in a gingival display, midline diastema, and crown length makes a smile beautiful and pleasant. Changes in crown width were not perceivable by all the three groups. Conclusion. Eastern Arabic laymen are more conscious about alterations in gingival display, midline diastema, and crown length in their smile. Hence, the orthodontist should pay attention to these factors during any orthodontic treatment.

Vestibulo-Oral inclination of maxillary and mandibular canines and bicuspids - a CBCT investigation

BACKGROUND

The aim of this retrospective study was to measure tooth and crowns axes of canines, first and second bicuspids of orthodontically untreated subjects with near normal occlusion to: 1. Define norms and reveal potential gender differences and 2. Discuss implications of the findings for orthodontics.

METHODS

The CBCT-datasets of 167 patients, 56 males (mean age 28.63 years ± 11.99 years) and 111 females (mean age 29.72 years ± 11.47 years) were used. Tooth- and crown axes were measured for right and left sides. Normal distribution was evaluated with the Kolmogorov-Smirnov-test. For gender comparison independent t-Tests and for comparison of right and left sides a paired t-Test were used for normally distributed data. For data not following normal distribution for gender comparison the Mann-Whitney-U-Test was used and for data comparing the two sides the Wilcoxon signed rank test was applied. The level of statistical significance was set at p ≤ 0.05.

RESULTS

Measurement of tooth axes revealed buccal inclination for both genders with maximum values for maxillary and mandibular canines. Statistical significant differences were only found for maxillary canines (P = 0.025) and lower second bicuspids (P = 0.016) respectively. Values for crown axes revealed oral inclination for both genders with maximum values for maxillary first bicuspids and in the mandible for first and second bicuspids. No statistical significant differences were found between the genders apart from asymmetry for crown axes for the upper first bicuspids for males (P = 0.006) and females (P < 0.001).

CONCLUSIONS

Our study reveals that irrespective of gender, oral inclination of the crowns of canines and premolars is the norm. The values of the most commonly used bracket prescriptions coincide with the average values found in our investigation. For esthetic reasons modifications of torque values can be considered.

Perception of adults' smile esthetics among orthodontists, clinicians and laypeople

OBJECTIVE

Smile esthetics has become a major concern among patients and orthodontists. Therefore, the aim of this study was: (1) To highlight differences in perception of smile esthetics by clinicians, orthodontists and laypeople; (2) To assess factors such as lip thickness, smile height, color gradation, tooth size and crowding, and which are associated with smile unpleasantness.

METHODS

To this end, edited photographs emphasizing the lower third of the face of 41 subjects were assessed by three groups (orthodontists, laypeople and clinicians) who graded the smiles from 1 to 9, highlighting the markers that evince smile unpleasantness. Kruskall-Wallis test supplemented by Bonferroni test was used to assess differences among groups. Additionally, the prevailing factors in smile unpleasantness were also described.

RESULTS

There was no significant difference (P = 0.67) among groups rates. However, the groups highlighted different characteristics associated with smile unpleasantness. Orthodontists emphasized little gingival display, whereas laypeople emphasized disproportionate teeth and clinicians emphasized yellow teeth.

CONCLUSION

Orthodontists, laypeople and clinicians similarly assess smile esthetics; however, noticing different characteristics. Thus, the orthodontist must be careful not to impose his own perception of smile esthetics.

Effect of buccolingual inclinations of maxillary canines and premolars on perceived smile attractiveness

INTRODUCTION

In this study, we aimed to investigate the effect of buccolingual inclinations of the maxillary canines and premolars on the perceived attractiveness of the smile when viewed from the frontal perspective.

METHODS

A smiling frontal photograph was taken of a man. A 3-dimensional digital dental model of this subject was constructed within which the buccolingual inclinations of the canines and premolars could be altered relative to the occlusal plane. Three-dimensional models of the altered digital models were then printed in resin and mounted on articulators. Frontal photos of the mounted models were taken and transferred to the smile image. A series of images was produced with the canines and premolars inclined buccally or lingually by different degrees. The smile images were assessed by 2 panels, orthodontists and laypeople.

RESULTS

There was a broad range of esthetic acceptability for the buccolingual inclinations of the maxillary canines and premolars. The range of preferred inclinations was not as broad. Smile esthetics was significantly compromised (P <0.01) when the canines were lingually inclined more than -12°, or the premolars were lingually inclined more than -15°, as perceived by orthodontists and laypersons. Buccally tipping the canines more than 6° also made the smile esthetics less satisfying (P <0.01).

CONCLUSIONS

It could be esthetically satisfying to position the teeth within the ranges of 0° to -7° of inclination for the canines and -3° to -11° of inclination for the premolars, as assessed by the orthodontists, or of 3° to -10° of inclination for the canines and 5° to -11° of inclination for the premolars, as assessed by the laypersons. Clinicians could exercise flexibility within this range, when compromising tooth positions for transverse jaw discrepancies.

The unique contribution of elements of smile aesthetics to psychosocial well-being

Pleasant smile aesthetics is an important contributory factor to psychosocial well-being. The aim of this study was to determine the psychosocial influence of smile aesthetics. The study was cross-sectional on a convenient sample that included patients, pupils, students and faculty staff. A total of 155 subjects (36% male) aged 12-39 (mean age 21, interquartile range 19-23) were included. Occlusal characteristics were recorded by the Index of Complexity, Outcome and Need, and smiling frontal view photographs were obtained. Fourteen variables were measured using photogrammetric analysis: smile width, visibility of buccal corridors, maximum teeth exposure, total gingival display, lip thickness, degree of occlusal cant and deviation from golden proportion of the teeth in maxillary intercanine sector. Psychometric instruments included the Psychosocial Impact of Dental Aesthetics Questionnaire and the Rosenberg Self-Esteem Scale. Statistical analysis comprised multiple linear regressions. Malocclusion severity is the most important predictor of psychosocial influence of smile aesthetics and self-esteem, the unique contribution of which accounts for a total of 4-27% of variability. Female gender is associated with higher psychological influence of dental aesthetics while male gender and older age with self-esteem. Malocclusions have higher psychosocial impact than parameters of mini- and micro-aesthetics of smile related to visibility of buccal corridors, amount of teeth exposure, gingival display, lip thickness, presence of occlusal cant and deviation from golden proportion of the teeth. It appears that people are not as focused on details of their smile as they are on distinctive malposition of teeth.

Analysis of smile esthetics in American Board of Orthodontic patients

OBJECTIVE

To investigate the common denominators of an esthetically pleasing smile in patients who were considered to be successfully treated upon the submission to American Board Orthodontics (ABO) clinical examination.

MATERIAL AND METHODS

A total of 462 patients were examined. Ninety subjects that fulfilled the inclusion criteria were included. Standardized digital smile photographs of the subjects were rated by 30 panel members, including orthodontists, general dentists, and parents of orthodontic patients, using a numeric version of the visual analog scale. Three groups were formed using the mean esthetic score±standard deviation range: unattractive (n=21), average (n=47), and attractive (n=22) smiles. Eleven smile characteristics were digitally measured on the photographs and compared between the groups using one-way analysis of variance and χ2 tests. Additionally, regression analyses were used to investigate the association of the smile characteristics with the esthetic score.

RESULTS

A significant difference was found between the three groups for the comparison of smile arc relationship (P<.001). When all the variables used in this study were entered in the regression analysis, a positive association was found (r=0.658; r2=0.434; P<.001). Additionally, two models were defined using stepwise regression. The first model included the smile arc (r=0.478; r2=0.228; P<.001), and the second model had both the smile arc and right gingival display/visible dentition display ratio (r =0.567; r2=0.321; P<.001).

CONCLUSIONS

A harmonious smile arc relationship and less gingival display during a smile are significantly associated with smile attractiveness in patients considered successfully treated according to ABO standards.

Effects of vermilion height on lip esthetics in Japanese and Korean orthodontists and orthodontic patients

OBJECTIVE

To evaluate the influence of vermilion height on the assessment of lip attractiveness by Japanese and Korean orthodontists and orthodontic patients.

MATERIALS AND METHODS

Vermilion heights were modified by increasing or decreasing the vermilion height in 1.0-mm increments from -3.0 mm to 3.0 mm with reference to an average vermilion height. Participants ranged from 15 to 29 years of age and comprised 29 Japanese and 25 Korean orthodontists and 96 Japanese and 72 Korean orthodontic patients. They all rated the attractiveness of seven images with altered vermilion height using a visual analog scale.

RESULTS

Across the participant groups, there were significant differences in the median esthetic scores for the seven vermilion height levels tested. The Japanese and Korean raters assigned the highest scores to the average vermilion height and assigned the lowest scores to the +3-mm increased vermilion height. The ranges of vermilion height preferred by orthodontists were found to be within the ranges preferred by orthodontic patients when evaluating the preferences in lip esthetics by country.

CONCLUSIONS

We conclude that the -1-mm to +1-mm range for the average vermilion height is considered attractive for lips for both Japanese and Korean people.