Esthetics: patients' perceptions of dental attractiveness

Evaluation of tooth color change after a bleaching process with different lasers

The aim of this in vitro study was to evaluate the efficiency of diode laser-activated bleaching systems for color change of teeth. 75 extracted teeth were studied in five different bleaching protocols. Group 1: diode laser 445 nm, 320 µm fiber, 0.5W, continuous wave mode, dose 53 J/cm2. Group 2: diode laser 970 nm, 320 µm fiber, 1W, continuous wave mode, dose 106.10 J/cm2. Group 3: diode laser 940 nm, bleaching handpiece, 7W, continuous wave mode, dose 105 J/cm2. Group 4: diode laser 940 nm, 300 µm fiber, 2W, continuous wave mode, dose 47.16 J/cm2. Group 5: bleaching process without laser activation. In groups 1, 2 and 5, teeth were bleached with Perfect Bleach Office + and in groups 3 and 4, LaserWhite20 bleaching gel was used. Tooth color was determined immediately after the bleaching process using a spectrophotometer. Color change data on the CIE L * a * b* system was analyzed statistically by the one-way ANOVA and Tukey's HSD test. All bleaching procedures resulted in a change of color. All laser groups (∆E * ab > 3) have statistically larger ∆E * ab values than the control group (∆E * ab = 0.73) (p < 0.05). The diode laser 445 nm has the largest ∆E * ab value (∆E * ab = 4.65) and results in a significantly higher color difference than all other groups. In terms of color score difference in VITA Shades, all laser-activated groups lead to a lightening effect while the control group leads to only a slight lightening effect. The diode laser 445 nm produced the greatest color difference. Laser-activated bleaching is more effective than conventional bleaching without light activation. The diode laser 445 nm performs best in this in vitro study.

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.

Evaluation and Comparison of the Geometrical Relationship of Tooth and Lip Arcs and Their Correlation to Smile Arcs Between Males and Females in a North Indian Population

Background With the increasing influence of social media, millennials and the generations that follow have increasingly pressing aesthetic concerns. Following this, there has been a sea change in treatment plans and procedures as well as the choice of material. Dentistry nowadays is dependent on digital data to compute and design prostheses; these technologies are often not readily available all over the world. The purpose of this research article is to measure the tooth arc (TA) and lip arc (LA) and their correlation to the smile arcs with a cohort consisting of males and females from a single center in northern India. The SA measurement, evaluation, and comparison of smile aesthetics in this young population may be used as a threshold to these smile variables so that prosthodontists can easily prevent or modify aesthetically displeasing features. This research article will be useful for cases requiring restorations and replacements of maxillary anterior teeth. Materials and methods In this research work, photographic analysis was used and photographs of hundred subjects were taken. The camera was fixed using a tripod, at an 11-inch distance from the face, so that a clear picture of the face could be taken from the tip of the nose to the chin. A digital single-lens reflex (DSLR) camera (Nikon D-60, with the Nikon DX AF-S Nikkor 18- 135mm lens, Tokyo, Japan) was used to take the facial photographs. As the posed smile is more predictable than the natural smile, subjects were asked to smile while keeping their natural head position (NHP). Parabolas were made with Math-GV software () and superimposed on the photographs to calculate the value. Results The mean LA shows greater curvature in the female population. There was no significant (p=0.92) relationship between TA curvature in the male (0.07±0.03) and female populations (0.08 ± 0.03), whereas the LA in males (0.10±0.03) and LA in females (0.12±0.04) showed a significant relationship (p=0.03) between both groups. The LA of the female population was found to be steeper than that of the male population. This study signifies that there is no significant difference (p=0.92) between the skeletal makeup of the male and female populations but the muscular activity and muscle function differ in the male and female populations. Regarding arc-wise comparisons in both male and female populations, the male population showed a statistically insignificant (p=0.27) correlation in lip and tooth arcs. But in the female population, the correlation between these arcs was statistically significant (p=0.01). Conclusion These study results provide useful guidance for evaluating anterior teeth and planning treatment for aesthetic restorative care. Clinicians should consider not only racial and gender differences when developing an aesthetic treatment plan but also the symmetry of the facial structure which should be in harmony with the dental arc. The harmony of each determinant of aesthetics, with each other, aids in promoting beauty as a whole.

Influence of smoking on the effectiveness of tooth whitening: a systematic review

OBJECTIVES

Perform a systematic review to evaluate the influence of smoking on the effectiveness of tooth whitening (TW) and to analyze whether tooth sensitivity is different between smokers and non-smokers.

MATERIALS AND METHODS

A systematic review modeled according to the PRISMA guidelines was conducted. PubMed, Embase, Web of Science, Cochrane, Scopus, and OpenGrey databases were searched for related clinical trials. The population, exposure, comparison, outcomes (PECO) was individuals who had TW performed, smoking individuals, non-smoking individuals, and effectiveness of TW, respectively. Risk of bias was assessed with the ROBINS-I tool, and data from included studies were extracted by two researchers independently. The certainty of the evidence was evaluated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach.

RESULTS

Five studies were selected for qualitative analysis. The ROBINS-I tool classified 3 studies as having a moderate risk of bias, one study as having a serious risk of bias, and one with a critical risk. GRADE performed only for color change results and showed a low certainty of evidence. Limited evidence suggests that effectiveness of TW between smokers and non-smokers is similar. The tooth sensitivity also does not seem to be influenced by smoking. Due to the heterogeneity of the data, a meta-analysis could not be performed.

CONCLUSIONS

Effectiveness of TW between smokers and non-smokers is comparable. The tooth sensitivity also does not seem to be influenced by smoking.

CLINICAL RELEVANCE

The effectiveness of bleaching among smokers and non-smokers appears to be similar. Tooth sensitivity during TW also appears not to be influenced by smoking.

Contemporary Smile Design: An Orthodontic Perspective

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

Factors influencing the aesthetics of smile: An observational study on clinical assessment and patient's perception

AIM

To clinically assess the aesthetics of smile and the possible influencing factors.

MATERIALS AND METHODS

In this explorative study, an initial questionnaire on demographic variables and perception of own quality of smile (Visual Analogue Scale) was administered by a first examiner. A second blinded assessor examined all patients and recorded clinical data. In addition, for each patient, the Smile Aesthetic Index (SEI) was calculated. Descriptive statistics and multilevel logistic models were performed.

RESULTS

One hundred consecutive subjects were enrolled. The mean SEI was 8.4 ± 1.2, while the mean patient's perception of smile was 7.1 ± 2.0. However, they did not correlate (r = 0.16 from -0.04 to 0.34; p = .12). Gingival recessions were perceived by 21.9% of subjects, tooth alignment by 38.6%, tooth dyschromia by 34.3%, and missing papilla/diastema by 26.7%. In particular, gingival recessions were perceived when they were deeper (p = .0342), located in the upper jaw (p = .0223), and corresponding to incisors (p < .0001) and canines (p = .0159) with respect to molars.

CONCLUSIONS

Clinical assessment and patient perception represent two important diagnostic phases. However, there is no correlation between them. Attention should be given to specific variables to provide the most comprehensive aesthetic analysis of smile.

(Neuro)Aesthetics: Beauty, ugliness, and ethics

The objective of this essay is a holistic view of aesthetics, ethics, and neuroaesthetics. After a few introductory case studies, aesthetics is systematically introduced as a philosophical subdiscipline. This perspective is then expanded from aesthetics to neuroaesthetics. Using various art forms as well as current media formats, the aspects of beauty and ugliness are discussed, and aesthetic properties are expanded to include ethical implications. These can be expressed through ideals of beauty and the compulsion for body transformation. This perspective is then expanded from aesthetics to neuroaesthetics. From this point of view of art, the so-called golden ratio will play a central role. It will be shown how representations affect people and what ethical implications are associated with the effects. Therefore, this essay first has to look at art from the perspective of neuroaesthetics, and then consider the ethical aspects of the beautiful and the ugly. The considerations lead to a brief discussion of Socrates's three sieves.

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.

Fiber reinforced composite supported restoration of congenitally missing tooth by minimally invasive approach: Two years follow-up

Maxillary lateral incisor is the most frequent congenitally missing anterior tooth of the permanent dentition. The absence of the anterior tooth can adversely affect the production/transmission of speech sounds, mental health, and facial aesthetics of an individual. Considering this, prosthetic rehabilitation of missing front tooth is important. The treatment alternatives include implant supported single crown, conventional fixed partial dentures (FPDs), and resin bonded FPDs that are unilaterally or bilaterally supported by metallic wings. However, with the development in adhesive dentistry fiber reinforced composite (FRC) supported FPDs have provided a workable substitute for traditional techniques because of their improved esthetics, minimal invasiveness, less cost, enhanced bond strength, and revocable nature. The current case, reports the two years follow up of twenty-four years old female patient, for whom the congenitally absent maxillary right lateral incisor was restored with FRC supported FPD.

Influence of lightness difference of single anterior tooth to smile attractiveness

OBJECTIVES

To evaluate the influence of lightness difference of a single anterior maxillary tooth on difference smile attractiveness.

METHODS

A frontal view full-portrait image of a smiling male Caucasian, was digitally modified altering a single tooth, creating a series of images with varying lightness (ΔL) for the maxillary central, lateral and canine. A total of 160 participants (80 dentists, 80 laypersons) were asked to fill out a Visual Analog Scale questionnaire for every image recording smile attractiveness.

RESULTS

For central incisors ΔL≥1 negatively affected attractiveness. There was a higher tolerance for lightness mismatch when one lateral incisor is lighter and the same applies when the canine was darker. Difference in lightness affected smile attractiveness both for dentists and laypersons. No difference between males and females was observed for the dentists. For laypersons, females perceived smiles with lightness difference as significantly less attractive compared to males. Dentist's age did not affect smile attractiveness perception. Younger laypersons perceived darker color, as less attractive.

CONCLUSIONS

Changes in lightness of a single anterior tooth significantly affected smile attractiveness in a different way for the central vs lateral vs canine. For the dentists, age and gender did not significantly affect smile perception, in contrast to laypeople.

CLINICAL SIGNIFICANCE

Lightness differences of a single anterior tooth affects smile attractiveness.

Conservative esthetic management of post orthodontic treatment discolored tooth with calcified canal: a case report

A case of pulp canal obliteration (PCO) two years after the completion of orthodontic treatment is presented. Post orthodontic treatment PCO is a rare finding. A 23 years old female presented with the discoloration of clinical crown of maxillary right central incisor. Radiographic examination revealed the calcified canal and diffused periapical radiolucency. Vitality tests were negative. A decision was made to do root canal treatment followed by the walking bleaching. After the successful completion of the root canal treatment the internal bleaching was performed. The discolored tooth showed significant improvement in color. Internal bleaching is a viable conservative treatment for improving esthetics in single non vital discolored tooth.

Prevalence and public knowledge regarding tooth bleaching in Saudi Arabia

Background:

Nowadays, cosmetic dentistry has become one of the most important sections of dentistry because patients care about the appearance of their smile with their general health. Hence, the present study was conducted to find the prevalence of public knowledge regarding tooth bleaching in Saudi Arabia.

Methods:

A cross sectional study with cluster sampling method was carried out in the central, northern, southern, eastern, and western regions of the Kingdom of Saudi Arabia. A modified close ended questionnaire in Arabic/English language was distributed among randomly selected shopping malls and social media (WhatsApp and Twitter) via link in Google Sheet. The survey questionnaires were distributed systematically to individuals entering the malls. The survey items were divided into two sections that included sociodemographic data and knowledge subscales. Regression analysis was done to measure the factors influencing the overall impression of bleaching/tooth whitening.

Results:

The sample comprised a total of 2543 respondents, of whom there were 1190 males (46.8%) and 1353 females (53.2%). When the population was asked the perceived or actual complication of bleaching, it was observed that the majority of those surveyed felt that there was either a real or perceived threat of tooth sensitivity followed by burning of the gums.

Conclusion:

Most of the participants heard about tooth bleaching via advertisements, and most of them have used home bleaching more than professional bleaching. Respondents with frequent dental visits had higher levels of knowledge on tooth bleaching compared to respondents with a lack of dental visits.

Tooth Shade Preferences among the General Public

PURPOSE

To identify laypersons' most preferred tooth shade as a function of observer and patient factors, namely patients' skin shade and observers' socio-demographics.

MATERIALS AND METHODS

Two online surveys using computer-designed perioral images with different shades of the skin and teeth were distributed to participants in Montreal (Canada) and San Francisco (USA). The first survey (n = 120) was designed to assess public preferences of tooth shade value, hue and chroma as a function of the skin color of the perioral image (model), and the demographic characteristics of the observer. The first survey included 6 sets of 9 identical perioral images. A different skin shade (from very dark to very light) was used for each set of images, and each set of images presented teeth with different tooth shades which included three different levels of value (2M1, 3M1, 4M1), hue (3L1.5, 3M1, 3R1.5), and chroma (3M1, 3M2, 3M3) of the Vita 3D Master shade guide. Participants were asked to choose their preferred image for each category (value, hue, chroma) within each set of skin shades. A second survey was performed to pinpoint the tooth shade that is preferred the most by the general public. In this survey, images with four tooth shades (1M1, 2M1, 3M1, 4M1) and 6 skin shades were distributed (n = 70). Ordinal logistic regression was used to identify significant predictors of preferred tooth shades.

RESULTS

Most of the participants preferred teeth with the highest value (54%), a neutral hue (59%) and the lowest chroma (89%). About 75% of the participants preferred 1M1 the lightest tooth shade over other shades regardless of their demographics or skin color of the model. Among the observer-related variable, age was the most significant predictor of people preferred tooth shade (p = 0.019).

CONCLUSION

This study showed that there are common preferences in terms of tooth shade value, hue and chroma among participants regardless of demographic variables and facial skin shades. This data could guide dentists for tooth shade selection in the clinical practice.

Three-dimensional evaluation of smile characteristics in subjects with increased vertical facial dimensions

INTRODUCTION

Patients seeking orthodontic treatment often have esthetic concerns (ie, they want a better smile). Patients with increased vertical facial dimensions have different smile traits than other patients. This study aimed to compare the smile characteristics of subjects with different vertical facial dimensions and to use stereophotogrammetry to evaluate the changes in facial animation upon smiling.

METHODS

One hundred twenty adolescents and young adults (aged 15-25 years) who were referred for orthodontic treatment were divided into 2 groups according to their vertical facial height: increased (n = 30) and normal (n = 30). Three-dimensional stereophotogrammetric images were obtained from the patients during rest and smile. The images were superimposed, and the displacements of specific landmarks were recorded. Linear, angular, and proportional measurements were recorded on the smile and rest images.

RESULTS

When smiling, horizontal movement of commissures was less (right, P = 0.038; left, P = 0.009), upper lip elevation was higher (P = 0.014), and the upper lip was shorter (P = 0.014) in the vertical group than in the normal group. In the vertical group, the interlabial gap was increased both at rest and when smiling (P <0.001). Statistically significant differences were found in smile index (P = 0.001), nasolabial fold displacement (P = 0.018), and lip angles (both P = 0.001) between groups.

CONCLUSIONS

Group and sex differences were observed when smiling. Careful consideration of these differences will help clinicians in proper diagnosis and treatment planning.

The potential factors affecting the perception of aesthetic smile among adult patients attending Dental clinics of Jazan University

Introduction: Aesthetic smile is an important part for every patient since it plays a vital role in his personality, selfconfidence and self-esteem. Aim: To assess the relationship between the potential factors affecting the perception of aesthetic smile among adult patients, to evaluate the patient's satisfaction toward their smile and to find the most common factors for their dissatisfaction caused by smile. Materials and methods: A 100 males and 100 females were evaluated for the presence or absence of aesthetic smile. The clinical examination was included categories related to personal aesthetic factors of the smile. A questioner designed by Goldstein to measure the patient's self-perception and satisfaction of their smiles was used. The data were pooled for analysis, statistical significance was set to p-value ˃ 0.05. Results: There was a significant differences in the parallel interpupillary line and coincided of dental midlines alone and with facial midlines in the aesthetic and non-aesthetic choices, also between the symmetry of maxillary central and lateralicisors, and canines with their axial inclinations choices (p< 0.05). Some group of questions showed significant differences among female and male subjects while, the male subjects Some questions were near to the statistical significant differences, while others showed no significace between males and females choices. Conclusion: Dental and facial factors showed highly significant relationship with aesthetic smile. So, it should be observed by a dental specialist to provide a proper treatment plan with respect to the potential factors of the aesthetics to help for self-satisfaction measurement.

Perception of Buccal Corridor Space on Smile Aesthetics among Specialty Dentist and Layperson

Objectives

The aim of this study was to assess and compare the perception of smiles with and without buccal corridor spaces (BCSs) among prosthodontists, orthodontists and laypersons on smile aesthetics.

Materials and Methods

Smiling photographs of subjects with wide BCSs were collected and digitally manipulated to eliminate the BCSs. Digitally altered and unaltered photographs were placed together and assessed for aesthetic appeal using visual analog scale of one to ten by prosthodontists, orthodontists, and laypersons. One-way analysis of variance (ANOVA) and two-way ANOVA were applied to evaluate the collected data using the Statistical Package for the Social Sciences (SPSS 22), Epi Info 6.0, and GraphPad Prism, version 6.0.

Results

The total mean value scores of smiles with BCSs were significantly higher than those of smiles without BCSs (P < 0.001). Orthodontists and prosthodontists significantly appreciated BCSs and graded the smiles with BCSs to be much more attractive (P > 0.005). Laypersons rated the smiles with BCSs with greater mean values, but the difference in mean values of smiles with and without BCSs was not significant (P < 0.005). No significant difference was found between the perceptions of prosthodontists and orthodontists.

Conclusion

The results of this study reveal that the smiles with BCSs were notably more desirable than the smiles without BCSs. Laypersons, orthodontists, and prosthodontists evaluated smiles differently. The smiles with BCSs were appraised much more pleasing by prosthodontists and orthodontists. Laypersons could not significantly appreciate BCSs, but rated smiles with BCSs as more acceptable.

Direct Restorations, Endodontics, and Bleaching: Materials and Techniques Used by General Dentists of New Zealand

Background

To investigate the selection and use of direct restorative materials, endodontic techniques adopted, and approaches to bleaching by general dentists in New Zealand.

Methods

A questionnaire comprising 19 sections and 125 questions was distributed via mail to 351 general dentists in New Zealand who were selected, at random, from the Dental Council of New Zealand's 2016 register.

Results

A total of 204 questionnaires were returned, of which 188 were usable. Direct resin composite was the most commonly used material for occlusoproximal cavity restorations in premolars (93.7%) and permanent molars (85.2%). Resin-modified glass ionomer cements (34%) and resin composite materials (31.4%) were more commonly used in the restoration of deciduous molars. Home-based vital bleaching was provided by a significant number of dentists (86%), while only 18% provided practice-based bleaching. Cold lateral condensation was the most commonly used obturation technique (55.8%), and 83% of respondents reported using rubber dam for treatments.

Conclusions

The findings from this study indicate that dentists in New Zealand are adapting to new materials and technologies to provide high quality care to their patients. Aesthetic treatments such as bleaching have become an integral part of general dental practice.

Children's Social Perception of Peers' Dento-Facial Condition: A Cross-Sectional Study

AIMS:

This study aimed to compare the participant’s perceptions about their peers’ dento-facial condition with different incisal appearances (intact, discoloured, fractured, and avulsed incisors).

MATERIALS AND METHODS:

A cross-sectional study was conducted among schoolchildren of both primary (8-11 years) and secondary (12-14 years) levels. Each participant was asked to judge photographs with one intact and three digitally modified central incisors giving the appearance of a traumatised tooth. Data on perceptions were collected for each condition using 12 attributes (8 positive and 4 negative; scored on a 4 point Likert scale). The positive, negative and total attribute scores were analysed separately by unpaired Student’s t-test. Repeated Measures ANOVA and Bonferroni post hoc analysis was also used.

RESULTS:

A group of 587 children participated in the study. The perception for intact and traumatised incisors about demographic factors is well appreciated. Among the gender delineation, girls showed a significant difference in judgment between discoloured and fractured incisors. In comparison to intact incisors, positive and total attributable scores were found to be significantly higher (P < 0.001), whereas negative attribute scores were significantly lower (P < 0.001) for traumatised incisors. Pairwise comparison showed high significance (p <0.001) between the intact and traumatised incisor conditions.

CONCLUSION:

The results demonstrated that visible dental trauma influenced the psychosocial judgment given by children towards their peers. This judgment would, in turn, affect their level of acceptance towards such appearances. Therefore, these conditions ought to be redressed as swiftly as possible.

CLINICAL SIGNIFICANCE: The primary purpose of this study was to highlight the psychosocial perceptions of children in judging their peers, regarding not only attractiveness but also intelligence, friendliness, confidence, outgoing nature, etc.

Relationship between tooth value and skin color in patients visiting Royal Medical Services clinics of Jordan

Background

Facial and dental aesthetics are becoming of great concern for patients, especially for the younger generation. Tooth color matching and selection is considered a vital element in order to create an attractive beautiful smile. The importance of tooth color matching is to adjust tooth colors to obtain a good match with adjacent teeth and the skin. This is considered a challenge especially if adjacent teeth were lost or records of patients’ teeth color were not available.

Objective

The aim of this study was to determine the relationship between skin complexion and tooth value in a Jordanian population.

Methods

A cross-sectional study of 520 individuals who were randomly selected and belonging to different age groups, ranging from 15–65 years, with equal sex distribution. These patients visited the dental clinics at different Jordanian military hospitals. The study was carried out over a period of one year from 2015 to 2016. The randomly selected sample was examined by one researcher. Shade of the middle third of the labial surface of central incisor was determined visually using VITA tooth guide, 3D-MASTER shade guide. Tooth shades were divided into two categories according to their value. The skin complexion was identified using Fitzpatrick skin type test, and was categorized into two categories (fair and dark). Data were statistically analyzed using Epi Info version 6.

Results

A statistically significant tooth shade value difference was discovered among subjects of different skin color (p<0.0001). Individuals with dark skin tend to have lighter teeth, while individuals with light skin tend to have darker teeth. Out of the 304 participants that were with dark complexion 274 (90%) have light teeth, and only 30 (10%) were with dark teeth. Out of the 216 participants with light complexion 172 (80%) have dark teeth and only 44 (20%) have light teeth.

Conclusion

Within the limitation of this study, there was an inverse relation between skin complexion and tooth value among a Jordanian population. Thus, considering the skin complexion when choosing tooth shades is helpful in achieving a pleasing good-looking smile, yet further investigations in this field must be carried out.

Tooth colour and whiteness: A review

OBJECTIVES

To review current knowledge concerning the application of colour science on tooth colour and whiteness description, measurement, distribution and its psychological impact.

DATA SOURCES

"Scopus" databases were searched electronically with the principal keywords tooth, teeth, colour, white, whiteness. Language was restricted to English and original studies and reviews were included. Conference papers and abstracts were excluded.

CONCLUSIONS

The appearance and colour of teeth are a common concern for patients across many populations and are associated with an increased desire for treatments that improve dental aesthetics, including tooth whitening. The application of colour science in dentistry has allowed the precise description of tooth colour and whiteness. Coupled with the advances in instrumental tooth colour measurement, such as spectrophotometers, colorimeters, spectroradiometers and digital imaging systems, these parameters are quantifiable in a reproducible and robust manner. These principles have been applied to the tooth colour distribution in many study populations, indicating, in general, differences in tooth colour for subject age and gender, but not for ethnicity. Psychophysical studies on tooth colour and whiteness via third party assessment of images indicate that whitened teeth lead to judgements that are more positive on personality traits such as social competence and appeal, intellectual ability and relationship satisfaction.

Lay preferences for dentogingival esthetic parameters: A systematic review

STATEMENT OF PROBLEM

An objective definition of the characteristics that render a smile esthetically acceptable in the eye of laypeople is lacking.

PURPOSE

The purpose of this systematic review was to identify, appraise, and synthesize the available evidence on the opinion of laypeople regarding the dentogingival characteristics that render a smile esthetically acceptable. The evidence was collected by surveying with standardized digitally modified smile images.

MATERIAL AND METHODS

Four databases were used to search English language studies published between January 1996 and December 2015. This was complemented by a manual search of 8 dental journals. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, 2 independent reviewers extracted the relevant characteristics of lay evaluators, the images evaluated, and the outcomes measure. Included studies were assessed in agreement with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. Outcomes were treated as a continuous variable, and when more than 1 article provided information on a parameter, the weighted arithmetic mean was calculated.

RESULTS

After 8851 articles were screened, 20 studies were included. Those studies addressed 20 different dentogingival esthetic parameters. The total number of participants interviewed was 3107. According to the Olmos classification, 6 studies had a high level of quality, and 14 studies had a moderate level of quality. The 2 reviewers agreed on all the quality assessments. In the articles reviewed, central incisors clearly played a key role in smile esthetics. Almost all dental, gingival, and occlusal parameters are related to the proportion, shape, and position of central incisors and their relation to the adjacent dental structures.

CONCLUSIONS

The present review provides the estimated thresholds of tolerability and ideal values of smile parameters determined by laypeople. This may guide clinicians in evidence-based diagnosis and the planning of dental esthetic treatments.

Assessment of the influence of gender and skin color on the preference of tooth shade in Saudi population

AIM

The aim of the study was to evaluate the influence of gender and skin color on the preference of different teeth shades in general population.

MATERIALS AND METHODS

Two standardized frontal smile photographs of male and female subjects were manipulated using photoshop to represent 4 skin colors [(type II, III, IV, and V) (Fitzpatrick scale)]. The teeth shades under each skin color were digitally manipulated to represent one of 6 teeth shades (BL1, BL2, BL3, BL4, B1 and A1). A questionnaire assessed demographic characteristics (age, nationality, gender, education level, occupation, and income) along with the satisfaction of their smiles. Male and female set of pictures with combination of skin colors and teeth shades were presented and participants were asked to select the most esthetically pleasing teeth shade with regard to gender and skin color. Cross-tabulations and chi-squared tests were used to perform the statistical analyses (α = 0.05).

RESULTS

Three hundred and thirty-six (60.4% male; 39.6% female) individuals participated in the study. The difference in the preferred teeth shades was significant among the male and female photographs across all skin colors (p < 0.05). Lighter teeth shades were preferred among female subjects compared to male subjects with the same skin color. In addition, lighter teeth shades were preferred among subjects with a lighter skin color and vice versa (p < 0.05).

CONCLUSION

Gender and skin color influences the perception of teeth shades among general population. Therefore, lighter tooth shades (BL1, BL2) for lighter skin color and comparatively darker tooth shades (BL4, B1, A1) for darker skin individuals should be prescribed as these are perceived as natural among Saudi population.

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.

Effects of tooth extraction on smile esthetics and the buccal corridor: A meta-analysis

Background/purpose

Smile esthetics is a critical factor for evaluating orthodontic treatment outcomes. The effects of tooth extraction on smile esthetics and buccal corridor remain controversial and have not been adequately investigated. Therefore, in this systematic review and meta-analysis, we evaluated the aforementioned effects.

Materials and methods

We searched clinical studies held in PubMed, MEDLINE, Embase, and the Cochrane Library up to May 2015, with no restriction. Study selection and data extraction were conducted by two reviewers independently. A random-effects model was used for conducting a meta-analysis to assess the mean difference between the esthetic score and the buccal corridor ratio of extraction and nonextraction groups.

Results

Six eligible studies were included in this meta-analysis. No significant difference was observed in the esthetic score and the buccal corridor ratio between extraction and nonextraction groups.

Conclusion

Tooth extraction does not affect smile esthetics or buccal corridor. However, additional detailed, large-scale, double-blinded, and randomized controlled trials are required for further evaluation.

Influence of Smile Arc and Buccal Corridors on Facial Attractiveness: A Cross-sectional Study

INTRODUCTION

Two aspects of the smile: the Smile Arc (SA) and Buccal Corridors (BC) have been the interest of the orthodontist in recent years.

AIM

The present study was undertaken to evaluate the influence of the smile arc and buccal corridors on facial attractiveness as evaluated by orthodontists, general dentists and laymen.

MATERIALS AND METHODS

Two subjects (one male & one female) were selected from the regional population fulfilling the criteria of an ideal smile arc and ideal buccal corridors. Frontal smile view photographs of these subjects were taken and modified by using adobe photoshop 7.0 to create combination of three smile arc variance and three buccal corridors variations respectively which were shown to 25 orthodontists, 25 general dentists & 25 laymen, to rate the facial attractiveness of each image on a rating scale.

RESULTS

All the three groups (laypersons, dentists and orthodontists) showed significant difference in ratings, indicating that they had different perceptions on the facial attractiveness.

CONCLUSION

Orthodontists were more precise in discerning the smile arc and buccal corridors compared to dentists and laypersons.

Three-dimensional evaluation of social smile symmetry

OBJECTIVE

To evaluate the social smile symmetry using three-dimensional (3D) stereophotogrammetric images.

MATERIALS AND METHODS

The study was conducted with 3D facial images of 30 individuals (age range 13-25 years). The rest position was considered as the reference image and the social smile image was aligned on this image using the best-fit alignment method. The spatial differences between the same points established on both images using 3D analyses were determined for right and left points in X, Y, and Z planes.

RESULTS

The highest difference related to spatial distance in right and left points was -0.56 mm (95% confidence interval [CI], -1.19, 0.06 mm) between right and left commissure (Com) points. The difference was not significant, and the Bland-Altman upper and lower limits were -3.85 mm and 2.71 mm, respectively. The highest difference for the transversal plane was found in Com points, similarly to the spatial distance (mean: 0.50 mm, 95% CI, -2.62, 1.02 mm). The differences between the changes in the left and right points in the Y and Z plane were not significant (P > .05).

CONCLUSIONS

The social smile was observed to show asymmetry in varying amounts in the different directions. Asymmetry increases in some cases, specifically for the corners of the mouth.

The Effect of Educational Status on the Perception of Social and Spontaneous Smiles

OBJECTIVE

The aim of the present study was to evaluate the effect of educational status on the perception of smile esthetics considering social and spontaneous smile patterns.

METHODS

The present study was conducted on 110 subjects with differing educational status. Of 110 subjects with a mean age of 39.4 years, 30 were primary school graduates, 30 were high school graduates, and 50 had a university or higher educational level. Four different black and white natural social and spontaneous smiling images, captured from a video recording of a 25-year-old female, were prepared displaying the full-face and oral area. A 10-cm visual analog scale (VAS) was used to evaluate the smile esthetics.

RESULTS

There were significant differences in the social and spontaneous smiles in a subjective assessment of the smile esthetics in full-face and oral views between participants having a different educational status (p>0.05). Compared with the other groups, the participants in the primary school graduate group gave higher esthetic scores in all the image groups. In terms of esthetic perception, this group was followed by high school graduates and participants with a university or higher level of education. In the four image groups, there was a significant difference between the primary school graduates and participants with a university or higher level of education (p<0.05).

CONCLUSION

Educational status is a sociodemographic factor that can affect the perception of smile esthetics. The esthetic scores both in social and spontaneous smile decrease with increasing education level, and the most remarkable difference exists between primary school graduates and those with university or higher level of education.

Patient's Perception on the Esthetic Outcome of Anterior Fixed Prosthetic Treatment

OVERVIEW

Patient's perception to the esthetic result of the treatment received can be different from a dentist opinion. Understanding patient's opinion, demand and expectation is part of successful treatment procedure.

OBJECTIVE

The purpose of this study was to investigate patient's opinion about the esthetic result of the fixed prosthetic treatment received in upper anterior teeth.

MATERIALS AND METHODS

About 90 volunteer subjects, 58 males and 32 females were given a self-evaluation questionnaire with 11 questions to respond as Yes or No. The questions regarded the esthetic result of a fixed prosthodontic treatment received for their upper anterior teeth. The same questioner was completed for each subject by three clinicians through clinical photographs for different views of subject's smile. Agreement between patients and clinicians was calculated for all subjects to evaluate patient's perception to their esthetic results.

RESULTS

An agreement of 47.8 to 72.2% was observed between patients and clinicians, and the average agreement was 53.64 to 60%. The highest agreement was related to satisfaction with the color of the crown and/or bridge margin while the least agreement was related to the satisfaction with the natural looking of the restoration.

CONCLUSION

There was variability in the agreement between the patients and the dentists with the satisfaction of the esthetic result of anterior restoration. Factor, such as gender, age and educational level may affect the results of the agreement.

The role of personality traits in self-rated oral health and preferences for different types of flawed smiles

Symmetric, aligned and luminous smiles are usually classified as 'beautiful' and aesthetic. However, smile perception is not strictly governed by standardised rules. Personal traits may influence the perception of non-ideal smiles. We aimed to determine the influence of personality traits in self-rated oral health and satisfaction and in the aesthetic preference for different strategically flawed smiles shown in photographs. Smiles with dark teeth, with uneven teeth, with lip asymmetry and dental asymmetry were ordered from 1 to 4 as a function of the degree of beauty by 548 participants, of which 50·7% were females with a mean age of 41·5 ± 17·6 years (range: 16-89 years). Self-assessment and oral satisfaction were recorded on a Likert scale. Personality was measured by means of the Big Five Inventory (extraversion, agreeableness, conscientiousness, neuroticism and openness), and the Life Orientation Test was used to measure optimism and pessimism. Of the four photographs with imperfect smiles, dental asymmetry was the most highly assessed in 63% of the sample, and the worst was lip asymmetry, in 43·7% of the sample. Some personality traits (above all conscientiousness and openness) were significantly correlated with the position assigned to the photographs with dental and lip asymmetry or with misaligned teeth. The extraversion, agreeableness and openness traits were correlated with the self-perceptions of oral health and aesthetics of the participants. Dental asymmetry seems to be better tolerated than lip asymmetry. Personality traits are weakly but significantly correlated with the aesthetic preference and oral health values, conscientiousness and openness being the most relevant domains in this sense.

An In Vitro Study on Effect of Ceramic Thickness and Multiple Firings on Colour of Metal Ceramic Restorations

Preparation of porcelain restorations that match the natural dentition has been a subject of great concern for many years. An understanding of the process by which the colour and translucency of fixed restorations are planned and obtained so as to replicate the colour of its adjacent teeth is important for achieving an esthetic restoration. This study was done to study the effect of fabrication procedures such as ceramic thickness and number of firing cycles on the colour of metal ceramic restorations. Metal ceramic samples with three different ceramic thicknesses; 0.5, 1 and 1.5 mm (N = 30, n = 10 per group) were fabricated. A3 shade of [VMK 95, VITA Zahnfabrik, Bad Sackingen, Germany] ceramic was used for the fabrication of samples. Samples were subject to multiple firing cycles and colour was measured after 2nd, 3rd, 4th, 6th, 8th and 10th firing cycle. Colour measurement was done objectively using spectrolino (Gretag Macbeth Inc., Germany) spectrophotometer. 'Repeated measures ANOVA' test was used for doing statistical analysis. No significant change was noticed in any of the four colour parameters between the baseline reading after second firing uptil the tenth firing for any of the three groups with different ceramic thicknesses. There was a consistent rise in L* or lightness of colour as the thickness of ceramic increased. Between group I and group III there was a consistent shift of a* axis towards the blue green side and there was a consistent shift in b* axis towards purple-blue with an increase in ceramic thickness. It was observed that there was a change in ΔE with a change in ceramic thickness. There was a change of about two units between group I and group II and a change of about one unit between group II and group III. Change in ΔE between group I and group III was the most significant, being about three units. It was concluded from the study that multiple firing cycles during fabrication of metal ceramic restorations do not have any effect on colour while colour varies with change in ceramic thickness.

Effects of transverse relationships between maxillary arch, mouth, and face on smile esthetics

OBJECTIVE

To identify the ideal ratios between the widths of the maxillary arch, mouth, and face, respectively, and to determine the range of acceptable esthetic variations based on these ideal ratios.

MATERIALS AND METHODS

A photograph of a young female with a harmonious smile was selected and digitally altered to produce two sets of images. The first image showed an altered intercanine width, while the second one showed an altered oral fissure breadth. These alterations were independently rated by judges, including 23 orthodontists and 30 undergraduates. The Mann-Whitney U-test was used to compare the scores given by male and female judges and those given by professional and nonprofessional judges.

RESULTS

The following ideal transverse ratios were determined: intercanine width/oral fissure breadth, 0.638; oral fissure breadth/interparopia width: the distance between left and right paropia, 0.617; and intercanine width/face width at the level of the labial commissures, 0.300. A range of -10% to +10% was proposed as the thresholds of esthetic smile evaluations. It was shown that gender of the raters had no effect on the rating of photographs, nor were there any statistically significant differences between the professional and nonprofessional judges' ratings.

CONCLUSIONS

Balanced transverse relationships in the facial region are important for smile esthetics, and there is a wide range of esthetically acceptable variations in the transverse relationships between the maxillary arch, mouth, and face.

The perception of smile attractiveness among Saudi population

Parameters of dental beauty change across time for varying reasons. Thus, an understanding of the factors that help or harm the attractiveness of a smile is an important step in creating attractive smiles. This study aimed to identify factors that affect smile perception and attractiveness among the Saudi population. A cross-sectional study was conducted among the Saudi population. Questionnaires were distributed to 130 dentists and final-year dental students, and to 130 laypersons. The questionnaire contained six smile photographs created by Photoshop^® software. There was a statistically significant difference in scale ratings, based on participant background, for the “gummy” smile picture (P-value =0.003), diastema picture (P-value =0.000) and the “Reverse” smile picture (P-value =0.004). As for sex, males significantly underscored the gummy picture (P-value =0.009). Older people accepted the gummy smile less than did younger people, but diastema was considered as one of the variations that spoiled the attractiveness of the smile. “Dental background” participants significantly identified the ideal smile better than the “nondental” group. The perception of diastema as a sign of beauty among Saudi population in the past has definitely changed, according to the results of our study, where diastema and reverse smile received the lowest score in this survey.

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.

Smile analysis: what to measure

Patients seek dental treatment to improve oral function as well as their attractiveness. In order to improve smile attractiveness, clinicians need to carry out a comprehensive smile assessment. The aim of this paper is to help clinicians to adopt a systematic approach toward smile assessment by introducing a smile assessment form.

CLINICAL RELEVANCE

Smile analysis is an essential part of smile diagnosis. A smile assessment form will assist clinicians in identifying and recording smile features for diagnosis and treatment planning.

Bleaching options for pulp-calcified teeth: case history reports

The aim of this article is to review some essential aspects of anterior tooth calcification and its esthetic treatment. Furthermore, three cases including different and successful bleaching strategies are reported.

Perceptions of midline deviations among different facial types

INTRODUCTION

The correction of a deviated midline can involve complicated mechanics and a protracted treatment. The threshold below which midline deviations are considered acceptable might depend on multiple factors. The objective of this study was to evaluate the effect of facial type on laypersons' perceptions of various degrees of midline deviation.

METHODS

Smiling photographs of male and female subjects were altered to create 3 facial type variations (euryprosopic, mesoprosopic, and leptoprosopic) and deviations in the midline ranging from 0.0 to 4.0 mm. Evaluators rated the overall attractiveness and acceptability of each photograph.

RESULTS

Data were collected from 160 raters. The overall threshold for the acceptability of a midline deviation was 2.92 ± 1.10 mm, with the threshold for the male subject significantly lower than that for the female subject. The euryprosopic facial type showed no decrease in mean attractiveness until the deviations were 2 mm or more. All other facial types were rated as decreasingly attractive from 1 mm onward. Among all facial types, the attractiveness of the male subject was only affected at deviations of 2 mm or greater; for the female subject, the attractiveness scores were significantly decreased at 1 mm. The mesoprosopic facial type was most attractive for the male subject but was the least attractive for the female subject.

CONCLUSIONS

Facial type and sex may affect the thresholds at which a midline deviation is detected and above which a midline deviation is considered unacceptable. Both the euryprosopic facial type and male sex were associated with higher levels of attractiveness at relatively small levels of deviations.

Evaluation of Color Changes in the Vitapan Classical Shade Guide After Disinfection

The purpose of this study was to evaluate how one, two, and three years of simulated treatments affect the colors of Vitapan Classical Shade Guide tabs after being chemically disinfected. Ten shade tabs (one, control; nine, disinfection) were evaluated visually and by chromameter for color changes after disinfection. Results showed that 0.62 ΔE was found after three years of disinfection. The color changes in the shade guide tabs were perceptible or noticeable to the human eye in eight out of 45 shade tabs (17.8%) after two years and in 13 out of 45 shade tabs (28.9%) after three years of treatment. It was concluded that one shade guide should be retained as a control and periodically compared with the shade guide in use to determine when the shade tabs in use should be replaced or discarded.

Composite images of upper front teeth--judgment of attractiveness and gender-specific correlation

The esthetic appearance of upper front teeth strongly depends on color, shape, size, width-to-height ratio, and position of teeth. In the past, these single esthetic aspects had been analyzed separately and not as a whole. Thus, the objective of this current study is to investigate the perception of the esthetics of upper front teeth whose image had been manipulated by composite photoimaging. In order to obtain the six composite images, one for each gender and group ("discontent," "average," and "content"), 320 students were photographed. Afterwards, the 6 composite images were rated by 128 independent participants (dentists and laymen), concerning attractiveness and gender. The composite images "average" and "content" were rated significantly more attractive than "discontent" images. The composite images rated as "attractive" were attributed to the female gender by the majority of the participants (61-85%); the "unattractive" images were predominantly (85-75%) related to the male gender. The participants were unable to judge the correct gender yet they assigned attractiveness to be a clearly female attribute. This "bias" can be utilized for the reconstruction upper front teeth, to emphasize the gender of the patient.

CLINICAL SIGNIFICANCE

The presented morphing technique can contribute to further study setups considering dental appearance and attractiveness. In the case of restoring upper front teeth, the parameters tooth shape, size, width-to-height ratio, and position of teeth should be individually chosen and can emphasize or dampen the perception of gender.

Normative values for the Oro-facial Esthetic Scale in Sweden

This study reports the findings and challenges of the assessment of oro-facial aesthetics in the Swedish general population and the development of normative values for the self-reporting Orofacial Esthetic Scale (OES). In a Swedish national sample of 1406 adult subjects (response rate: 47%), OES decile norms were established. The influence of sociodemographics (gender, age, and education), oral health status and general health status on OES scores was analysed. Mean ± standard deviation of OES scores was 50.3 ± 15.6 units (0, worst score; 70, best score); <1% of the subjects had the minimum score of 0, and 11% had the maximum score of 70 OES units. Orofacial Esthetic Scale score differences were (i) substantial (>5 OES units) for subjects with excellent/very good versus good to poor oral or general health status; ii) small (2 units), but statistically significant for gender (P = 0.01) and two age groups (P = 0.02), and (iii) absent for subjects with college versus no college education (P = 0.31) or with and without dentures (P = 0.90). To estimate normative values for a self-reporting health status, instrument is considered an important step in standardisation, and the developed norms provide a frame of reference in the general population to interpret the Orofacial Esthetic Scale scores.

Factors to consider when treatment planning for patients seeking comprehensive aesthetic dental treatment

Co-operation between specialties, improvements in dental materials, bonding technology, increase in public awareness of 'cosmetic dentistry' and patients' desires to improve their appearance, mean that, increasingly, dental practitioners are being asked how elective treatment may be used to improve their patients' smiles. Traditionally, a dentist's role has been to treat disease and promote oral health. Elective, invasive dental treatment needs careful consideration and, often, interdisciplinary planning. The issues dentists may need to consider and discuss with their patients are outlined with reference to dental literature.

CLINICAL RELEVANCE

Requests to dentists to embark upon complex elective treatments to improve their patients' dental appearance are on the increase. It is important that clinicians appropriately assess cases prior to committing to a treatment plan. Considerations to be taken when assessing these patients are discussed.

Influence of buccal corridor dimension on smile esthetics

OBJECTIVE: To assess the influence of buccal corridor width on smile esthetics of male and female, Caucasian and Afro-descendant subjects by means of digitally manipulated photographs, as well as compare assessments of full-face view (FFV) and close-up view of the mouth (CUVM) images. METHODS: Facial photographs were taken of four adults' smile, two Caucasians and two Afro-descendants of both genders. The resulting images were digitally manipulated with the aim of rendering - from each original smile - three other smiles simulating three different buccal corridor widths, namely, narrow, medium width and wide. The rendered images, 12 of which portraying FFVs and 12 providing CUVMs, were assessed by 60 examiners who rated the attractiveness of each smile by means of a visual analog scale (VAS). The data were treated with ANOVA and Tukey's post test to compare the different buccal corridors, and Student's t test to compare the two image views (FFV and CUVM). RESULTS: Medium width buccal corridors were considered the most attractive in the four individuals investigated, both in the assessment of FFVs and CUVMs (p < 0.05). Comparison between the narrow and wide buccal corridors, in general, showed no statistically significant differences (p > 0.05). Furthermore, no statistically significant difference was found between the analyses of FFVs and CUVMs (p > 0.05). CONCLUSION: The buccal corridor exercised a remarkable influence on smile esthetics, with the medium width group being rated as the most attractive. No influence was exerted by the individuals' face, ethnicity or gender.

Maxillary yaw as the primary predictor of maxillary dental midline deviation: 3D analysis using cone-beam computed tomography

PURPOSE

The purpose of this study was to investigate which factors affect upper dental midline deviation in dentofacial deformity patients using cone-beam computed tomography analysis.

PATIENTS AND METHODS

Twenty-eight patients were selected for this study. Subjects were divided into 2 groups according to the amount of upper incisor (U1) midline deviation from the clinical facial midline: group 1 (U1 deviation <2 mm) and group 2 (U1 deviation >2 mm). Linear measurements, angles, and reference planes on 3-dimensional (3D) computed tomograms were obtained. The predictor variables were maxillary yaw, palatal plane angle, differences of maxillary point to the coronal and sagittal planes, and maxillary canting. The outcome variable was U1 deviation. The variables between the 2 groups and 2 sides were analyzed with a t test. Pearson correlation coefficient and multiple regression analysis were also calculated within each group for each measurement against the U1 deviation to determine which variables affect U1 deviation. P < .05 was considered statistically significant.

RESULTS

The patients were evenly distributed between each group (n = 14 in each group). There was significant deviation of U1 from the sagittal plane in group 2 compared with group 1 (0.99 mm in group 1 vs 1.73 mm in group 2, P < .05). When we compared yaw with the sagittal plane, group 2 was more rotated than group 1 (1.16° in group 1 vs 2.28° in group 2, P < .01). Through multiple regression analysis, the primary predictor variable for U1 deviation was maxillary yaw (P < .05).

CONCLUSIONS

This study suggests that maxillary yaw is the primary contributing factor for upper dental midline deviation. The use of maxillary yaw should be considered when one is performing orthognathic surgery in patients with U1 deviation to achieve optimum esthetics.

From symmetry to asymmetry? The development of smile

The left side of the face has been reported to be more expressive than the right side in human adults. The developmental origin of this lateralization, however, is unknown. Chimeric still composite photos of smiling faces of 0-5 months (n=61), 6-12 months (n=67) old infants, 3-8 years old children (n=78), and 32 adults (>18 years) were rated for intensity by 90 judges. The results showed left-hemiface dominance in adults only, and not in infants or children. It can be speculated that this early functional symmetry may evolutionarily increase attractiveness and elicits secure bonding and care.