Orthodontic Aligners: Current Perspectives for the Modern Orthodontic Office.

Orthodontic aligners are changing the practice of orthodontics. This system of orthodontic appliances is becoming the mainstay appliance of choice for orthodontic offices in many countries. Patient preferences and lifestyle needs have made this appliance the primary choice when seeking care. In the early days, appliances lacked the efficiency and effectiveness of traditional bracket-wire systems, but modern systems are now able to handle a more comprehensive orthodontic caseload. Current systems provide newer biomechanical strategies and artificial intelligence-driven tooth movements for better outcomes. These improvements now mean that an orthodontist can be better prepared to manage a larger number of orthodontic malocclusions. This paper aims to discuss some of the evolution of orthodontic aligners and to describe to orthodontists the fundamentals of aligner therapy. In addition, it will provide an evidence-based outcome to the existing treatment outcomes in the current literature.

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

OBJECTIVES: The aims of this study were to assess smile attractiveness of a collection of 68 smiling photographs of successfully treated cases submitted to the American Board of Orthodontics (ABO) clinical examination and identify variables that influence the assessment. MATERIALS AND METHODS: A panel of 81 non-Caucasian assessors from various clinical disciplines were instructed to score the smile attractiveness on a visual analog scale from 1 (least attractive) to 10 (most attractive) and to select which components contributed to a lesser attractive smile. The mean, standard deviations (SDs), and quartiles of the smile attractiveness were obtained with descriptive statistics. Multilinear regression analysis was performed to investigate the scores of the perceived quality of smile attractiveness when the clinical disciplines and gender of the assessors were the factors taken into consideration. Receiver operating characteristic (ROC) curve was generated to establish the relationship between smile attractiveness and the achievement of a perfect smile. RESULTS: The mean (SD) rating of each clinical photograph of the anterior occlusion on smiling ranged from 3.11 (1.47) as the least attractive smile to 7.59 (1.45) as the most attractive smile. The overall mean (SD) score for smile attractiveness was 5.30 (1.10). Problems associated with teeth, gingiva, and lips corresponded with a reduction of the smile attractiveness score by 1.56, 1.82, and 1.47, respectively. Gender was not associated with smile attractiveness ratings. Orthodontists, periodontists, and prosthodontists demonstrated no difference in the ratings, while plastic surgeons were more critical than orthodontists regarding smile attractiveness. CONCLUSIONS: This study suggested that only 2 out of 68 AOB validated treatment finishes had a perfect and attractive smile.

Esthetic evaluation of Asian-Chinese profiles from a white perspective.

INTRODUCTION: Immigration from Asian countries to North America and Australia has resulted in more Asian patients treated by white orthodontists. Planning treatment for patients of different ethnicities can be a challenge. The aim of this study was to establish baseline data for the assessment of Asian-Chinese profiles from a white perspective. METHODS: Two Asian-Chinese profile images, 1 male and 1 female, were modified to create 7 profiles for each gender. Each profile showed a distinct characteristic: bimaxillary protrusion, protrusive mandible, retrusive mandible, normal profile (Class I incisor with Class I skeletal pattern), retrusive maxilla, protrusive maxilla, and bimaxillary retrusion. The images were viewed and ranked by 142 white examiners in 3 cohorts: 31 orthodontists, 31 dental students, and 80 laypersons from a mixed multi-ethnic metropolitan community. The facial anatomy that played the most important role in their decision making was also noted. Collected data in the form of ranks were statistically analyzed by using repeated measures analysis of variance. RESULTS: All examiners preferred the normal Class I or bimaxillary retrusive profiles in both sexes; the male profile ranked the least attractive was the protrusive mandible, and the female profiles ranked the least attractive were the protrusive mandible and the retrusive mandible. Orthodontists, dental students, and laypersons demonstrated similar trends in ranking the profiles. The preferred profiles diverged from bimaxillary protrusive and Class III profiles (maxillary retrusion and mandibular protrusion), which are the usual norms for ethnic Asian-Chinese. The upper lip, the lower lip, and the chin had the most emphasis when the examiners were ranking the profiles. This finding was also common in all 3 groups. CONCLUSIONS: This study demonstrated strong cohesive trends in establishing ideal facial esthetics of Asian-Chinese profiles evaluated by white persons in a multi-ethnic metropolitan community.

Outcome of orthognathic surgery in Chinese patients. A subjective and objective evaluation.

OBJECTIVE: To evaluate the outcome of orthognathic surgery by objective cephalometric measurement of posttreatment soft-tissue profile and by subjective evaluation of profile esthetics by laypersons and clinicians. MATERIALS AND METHODS: The sample consisted of 30 Chinese patients who had completed combined orthodontic and orthognathic surgical treatment. The posttreatment cephalograms of these patients were analyzed with respect to profile convexity, facial height, and lip contours and these were compared to the previously established esthetic norms. Line drawings of the soft-tissue profile were displayed to a panel comprising six laypersons and six clinicians who scored the esthetics of each profile using a 7-point scale. RESULTS: Complete normalization of cephalometric soft-tissue variables was not achieved with orthognathic surgery in most patients, with four of the six soft-tissue cephalometric measurements showing significant differences compared to the esthetic norms. There were good correlations in the esthetic scores between laypersons and clinicians, even though clinicians tend to rate the profiles more favorably. Facial convexity and facial height did not significantly influence the subjective scores of both the laypersons and clinicians. Lower lip protrusion was the only cephalometric variable that significantly influenced clinicians' assessment of profile esthetics (P<.01). CONCLUSIONS: Profile convexity and lower facial height proportion had little influence on both lay and professional perception of profile esthetics. Lower lip position is the only cephalometric variable that significantly influenced clinicians' assessment of profile esthetics.

An Asian community's perspective on facial profile attractiveness.

AIM: To assess the facial profile preferences of laypersons in an Asian community and the influence of age, ethnic and gender on profile selection. METHODS: A sample of 149 laypersons (65.1% Chinese, 21.5% Malays and 13.4% Indians), comprising of 112 females (75.2%) participated in the study. The mean age was 24.6 years (SD 4.4). A facial profile photograph and a lateral cephalometric radiograph of a Chinese male and female adult with a normal profile and a class I incisor and skeletal relationship were digitized to create a baseline template. Computerized digital photographic image modification was carried out on the template to obtain seven facial profiles [bimaxillary protrusion, protrusive mandible, retrusive mandible, normal profile (incisor and skeletal class I pattern), retrusive maxilla, protrusive maxilla and bimaxillary retrusion] for each gender. The laypersons were asked to rank the profiles of each gender on a scale of 1 (very attractive) to 7 (least attractive). RESULTS: Orthognathic Chinese male and female profiles were perceived to be the most attractive. A male orthognathic profile with normative Chinese cephalometric values was perceived to be more attractive than a 'flatter' bimaxillary retrusive profile. Bimaxillary retrusion and normal Chinese female profiles were perceived to be the most attractive. A male or female profile with a protrusive mandible was judged to be the least attractive. Age, gender and ethnicity were nonsignificant predictors for the most attractive female profile. CONCLUSIONS: Orthognathic Chinese male and female profiles were judged to be the most attractive by Asian adult laypersons. Male and female profiles with mandibular protrusion were judged to be the least attractive.

Perceptions of dental esthetics of Asian orthodontists and laypersons.

INTRODUCTION: The aim of the study was to determine the impact of anterior dental crowding, overjet, overbite, dental spacing, and type of malocclusion on dental esthetic perceptions of Asian orthodontists. METHODS: Twenty-one Asian orthodontists (10 men, 11 women) and 158 adult laypersons (38 men, 120 women) rated the attractiveness of 50 pairs of black-and-white intraoral photographic prints of various types of malocclusions. Each pair included a frontal and a right buccal view of the dentition at maximum intercuspation. Raters used a visual analogue scale (VAS), with "least attractive" (0 mm) and "most attractive" (100 mm) as the 2 extremes, to score the dental esthetics of the photographs. A principal investigator objectively measured the dental traits from study models. Linear regression analysis was performed with VAS scores as the dependent variable and anterior dental crowding, overjet, and overbite measurements as the independent variables. Independent sample t tests were used to determine the effect of dental spacing on the VAS scores. The Kruskal-Wallis test was used to determine the effect of type of malocclusion (Class I, Class II Division 1, Class II Division 2, Class III) on VAS scores. RESULTS: Increased overjet (>6 mm) and severe maxillary dental crowding (>8 mm) were found to be significantly correlated with laypersons' VAS scores (P <.05). Reverse overjet was found to be significantly correlated with orthodontists' VAS scores (P <.05). No significant correlation was found between overbite, dental spacing, and VAS scores. Class III malocclusions were significantly perceived to be the most unesthetic by orthodontists. CONCLUSIONS: Overjet was the major occlusal trait that influenced the perceptions of dental esthetics of both laypersons and orthodontists.

Occlusal status in Asian male adults: prevalence and ethnic variation.

The purpose of this study was to determine the occlusal status in young Asian male adults of three ethnic groups. Study models of a sample of male army recruits (N = 339, age 17-22 years) with no history of orthodontic treatment were assessed. The ethnic proportions of the sample were Chinese 76.1% (n = 258), Malay 17.7% (n = 60), and Indian 6.2% (n = 21). British Standard Institute (BSI) and Angle's classification were used to determine incisor and molar relationships, respectively. Chi-square test or Fisher's Exact test was performed to compare the occlusal traits between ethnic groups. The distribution of incisor relationships of the total sample consisted of Class I = 48.1%, Class II/1 = 26.3%, Class II/2 = 3.2%, and Class III = 22.4%. Right Angle's molar relationships were 49.9%, 24.5%, and 24.2% whereas left Angle's molar relationships were 53.1%, 25.1%, and 21.2% for Class I, II, and III, respectively. Comparison between ethnic groups found that Indian subjects were more likely to have Class II/1 malocclusions and clinically missing permanent teeth (P < .05). The study found that the overall prevalence of malocclusion (BSI) was Class I, Class II/1, Class III, and Class II/2 in descending order of proportions. Angle's Class I molar was most prevalent followed by Class II and Class III relations. A significant difference in occlusal status between the ethnic groups was found regarding incisor relationship and missing permanent teeth (P < .05).

Malocclusion severity in Asian men in relation to malocclusion type and orthodontic treatment need.

INTRODUCTION: The purpose of this study was to assess the severity of malocclusion in young Asian men in relation to types of malocclusion and orthodontic treatment need. METHODS: Study models of 339 male army recruits (age, 17-22 years) with no history of orthodontic treatment were assessed. The peer assessment rating (PAR) index was used to determine the severity of their malocclusions. Logistic regression and receiver operating characteristics (ROC) curves were performed to evaluate the PAR index in relation to treatment need assessed by the dental health component (DHC) and the esthetic component (EC) of the index of orthodontic treatment need. RESULTS: The mean PAR scores were 17, 20, 28, and 18 for Class I, Class II Division 1, Class II Division 2, and Class III, respectively. PAR scores were highly correlated with DHC and EC scores (P < .001). An increase of 1 point in the PAR score significantly increased the likelihood of orthodontic treatment need for dental-health reasons or esthetic impairment (by 1.17 times [95% CI 1.13-1.21] or 1.25 times [95% CI 1.19-1.31]). The areas under the ROC curves for PAR index were 84% and 94% for the DHC and EC assessments, respectively, suggesting that PAR scores were better predicators of esthetic than dental health impairment for assessing Asian malocclusions. The optimum cutoff points were PAR scores of 17 and 20 for dental health and esthetic impairment, respectively. CONCLUSIONS: Class II malocclusions were more severe than Class I or III in Asian men. Malocclusions with definite treatment need had PAR scores that were significantly greater than those with borderline, little, or no need. ROC curves showed that the PAR index had an acceptable level of validity with the professional assessment of orthodontic treatment need in Asian malocclusions. The optimum cutoff PAR scores were 17 and 20 in relation to DHC and EC assessment, respectively. The PAR index was more predictive of esthetic than dental health need.

Professional assessment of facial profile attractiveness.

INTRODUCTION: The aim of this study was to compare the assessments of Chinese facial profile attractiveness by orthodontists and oral surgeons. METHODS: The sample comprised 31 dental professionals (20 orthodontists, 11 oral surgeons) in an Asian community. Facial profile photographs and lateral cephalometric radiographs of 2 Chinese adults (1 man, 1 woman) with normal profiles, Class I incisor relationships, and Class I skeletal patterns were digitized. The digital images were modified by altering cephalometric skeletal and dental hard tissue Chinese normative values in increments of 2 standard deviations in the anteroposterior plane to obtain 7 facial profiles for each sex. The images were bimaxillary protrusion, protrusive mandible, retrusive mandible, normal profile (Class I incisor with Class I skeletal pattern), retrusive maxilla, protrusive maxilla, and bimaxillary retrusion. The Mann-Whitney U test was used to determine professional differences in assessment. Multiple regression analysis was performed with age, professional status, sex, and number of years in practice as independent variables. RESULTS AND CONCLUSIONS: A strong correlation was found in the profile assessment between orthodontists and oral surgeons. Normal and bimaxillary retrusive Chinese male and female profiles were judged to be highly attractive by orthodontists and oral surgeons. Chinese male and female profiles with protrusive mandibles were judged the least attractive. There was a difference in professional opinion about the most attractive male profile (P < .05), with orthodontists preferring a flatter profile and oral surgeons preferring a fuller normal Chinese profile. Sex of dental professionals and number of years in clinical practice were found to affect profile rankings.

A comparative assessment of the perception of Chinese facial profile esthetics.

INTRODUCTION: The aim of this study was to compare the perception of male and female Chinese facial profile esthetics between dental professionals, dental students, and laypersons. MATERIAL: The sample comprised 31 dental professionals (20 orthodontists, 11 oral surgeons), 92 dental students, and 152 laypersons in an Asian community. The facial profile photographs and lateral cephalometric radiographs of a Chinese man and a woman, each with a normal profile, a Class I incisor relationship, and a Class I skeletal pattern, were digitized. The digital images were modified to obtain 7 facial profiles for each sex. The images were constructed by altering cephalometric skeletal and dental hard tissue Chinese normative values by 2 standard deviations in the anteroposterior plane only. The 7 profiles were (1) bimaxillary protrusion, (2) protrusive mandible, (3) retrusive mandible, (4) normal profile (Class I incisor with Class I skeletal pattern), (5) retrusive maxilla, (6) protrusive maxilla, and (7) bimaxillary retrusion. RESULTS: Normal and bimaxillary retrusion Chinese male and female profiles were perceived to be highly attractive by all 3 groups. Profiles with a protrusive mandible were perceived to be the least attractive. Dental professionals, dental students, and laypersons were highly correlated for the perception of male (r > 0.67) and female (r > 0.93) profile esthetics. All correlation coefficients were found to be significant for the perception of female profiles, but, for male profiles, only the correlation coefficient between dental students and laypersons was significant. CONCLUSIONS: Chinese male and female profiles that were normal or had bimaxillary retrusion were perceived to be highly attractive by dental professionals, dental students, and laypersons, and profiles with a protrusive mandible were perceived to be the least attractive. Dental students and laypersons were more tolerant of a male profile with a retrusive mandible than were dental professionals, and all groups were more tolerant of bimaxillary protrusion in women than in men. Dental professionals, dental students, and laypersons had a similar trend in male and female esthetic preferences. The perception of female profiles by all 3 groups was highly and significantly correlated. Only the perception of male esthetics by dental students and laypersons was not significantly correlated with dental professionals.

Orthodontic treatment need in Asian adult males.

Orthodontic treatment in adults has gained social and professional acceptance in recent years. An assessment of orthodontic treatment need helps to identify individuals who will benefit from treatment and safeguard their interest. The purpose of this study was to assess the objective and subjective levels of orthodontic treatment need in a sample of orthodontically untreated adult Asian males. A sample of male army recruits (n = 339, age 17-22 years, Chinese = 258, Malay = 60, Indian = 21) with no history of orthodontic treatment or craniofacial anomalies participated in the study on a voluntary basis with informed consent. Impressions for study models were taken. Objective treatment need was assessed based on study model analysis using the Index of Orthodontic Treatment Need (IOTN). Questionnaires were used to assess subjective treatment need based on subjective esthetic component (EC) ratings. Fifty percentage of the sample had a definite need for orthodontic treatment (dental health component [DHC] grades 4 and 5), whereas 29.2% had a moderate need for treatment (DHC grades 3). The occlusal trait most commonly identified was dental crossbite. Malay males had the highest percentage with a definite need for treatment for both dental health and esthetic reasons in comparison with Chinese and Indian males. However, there was no difference in the level of treatment need among the ethnic groups (P > .05). No correlation between objective and subjective EC scores was found (P > .05). A high level of investigator-identified treatment need was not supported by a similar level of subject awareness among the adult sample.