Influence of lower facial height changes on frontal facial attractiveness and perception of treatment need by lay people

Influence of facial width on the perception of lip protrusion and its differences between profile and 3-dimensional video clip

INTRODUCTION

This study evaluated the influence of facial width on the perception of lip protrusion and investigated the concordance between 2-dimensional (2D) profile images and 3-dimensional (3D) video clips in assessing lip protrusion.

METHODS

An Asian female standard head model was created using 3D modeling software. Eight head models were constructed by modifying the standard head model in terms of facial width (broad, neutral, and slim) and lip protrusion (retrusive, straight, and protrusive). Overall, 97 Asian raters rated the lip protrusion from the 2D profiles and 3D rotation video clips of the 9 models.

RESULTS

No significant differences were found in the perception of lip protrusion in terms of sex, age, or occupation. Compared with the 2D profiles, the 3D video clips were rated as more protrusive in 8 of the 9 head models, with the retrusive broad, retrusive neutral, straight broad, and straight slim faces showing statistical significance (P <0.01). The rating is significantly higher in slim faces than in broad faces across the 3 groups of 2D profiles (P <0.01). For 3D video clips, the rating was higher in slim faces than in broad faces in all 3 groups, whereas differences were significant in the straight and protrusive groups only (P <0.01).

CONCLUSIONS

In this study, 3D video clips were more sensitive to the perception of lip protrusion than were 2D profiles to some extent. The lips were rated relatively more protrusive in a slim face than in a broad face. Therefore, the relationship between facial width and lip protrusion should be considered in orthodontic treatment goals and treatment plans.

Using Artificial Intelligence to Quantify Sexual Dimorphism in Aesthetic Faces: Analysis of 100 Facial Points in 42 Caucasian Celebrities

Background

Sexual dimorphism has been studied in the faces of average populations and worldwide celebrities; however, a focused analysis of attractive Caucasian faces has not been conducted.

Objective

The study harnesses the power of artificial intelligence (AI) to efficiently analyze these facial patterns in attractive Caucasian male and female celebrities.

Methods

Twenty-one male and 21 female Caucasian celebrities were selected based on popular editorial rankings, modeling agencies, and casting directors from 2017 to 2022. Frontal photographs of celebrities aged 23 to 42 without facial animation were selected. One hundred facial landmarks were identified using semi-automatic image analysis software consisting of modified Apple Vision (Cupertino, CA) machine-learning algorithms with additional custom landmarks. Measurements were converted to absolute distances by fixing subjects' white-to-white corneal diameters to the validated average in Caucasians.

Results

Attractive females had significantly greater upper and middle facial proportions, more uniformly divided facial thirds, and greater canthal tilt compared with males. Attractive males had significantly greater facial height, bizygomatic and bigonial widths, medial and total brow lengths, and alar width than females. The golden ratio (1.618) was observed in the ratio of facial height to bigonial width in females (1.613), and attractive males closely approximated that ratio (1.566). There were no significant differences in interpupillary distances, eyebrow angles, or horizontal palpebral fissure lengths. No faces in either sex exhibited scleral show.

Conclusions

The study is the first to utilize AI in quantifying key sexual dimorphisms among Caucasian celebrity faces. Identifying these contemporary patterns may provide valuable considerations in planning facial aesthetic and gender affirmation surgery.

Level of Evidence 3

Can smile influence the lower anterior vertical facial height on frontal view in an adult Asian female subject? A cross-sectional study

Objectives:

Smile is a universal phenomenon, the effect of which is not discovered on the lower anterior facial height (LAFH). The objective of this study was to determine the influence of smile on different LAFH in frontal view as assessed by different panels of raters using visual analog scale (VAS) in a female subject.

Material and Methods:

The frontal photographs (at rest and on smile) were taken at natural head position of a female subject aged 28 years old after taking informed consent. LAFH of the photographs was modified using a Photoshop software (Adobe Systems, San Jose, Calif.). Sixty raters equally divided into orthodontic residents, general dentists, and laypersons were given a VAS to make subjective assessments of facial attractiveness of the modified photographs. Comparison of raters’ scores was done using Kruskal–Wallis and Mann–Whitney U-tests. Wilcoxon Signed-Rank test was used to compare the esthetic scores of the subject at rest and with smile.

Results:

The mean age of the all raters was comparable (early adulthood). All raters preferred normal or slightly shorter LAFH in both postures, that is, at smile and rest. Similarly, all raters disliked long face modifications. On comparing smile and rest photographs at various LAFH, we found less VAS scores for smile. Gender of raters played no role in difference of VAS scores.

Conclusion:

All the panels of rater found normal LAFH to be the most attractive; however, the panels disliked long face modifications on both smile and at rest. Smile had no positive influence on the VAS scores as assumed so the effect of “Smiloflage” must be investigated further to understand it properly.

Valid 3D surface superimposition references to assess facial changes during growth

Currently, the primary techniques applied for the assessment of facial changes over time utilize 2D images. However, this approach has important limitations related to the dimensional reduction and the accuracy of the used data. 3D facial photography has been recently introduced as a risk-free alternative that overcomes these limitations. However, the proper reference areas that should be used to superimpose serial 3D facial images of growing individuals are not yet known. Here, we tested various 3D facial photo superimposition reference areas and compared their outcomes to those of a standard anterior cranial base superimposition technique. We found that a small rectangular area on the forehead plus an area including the middle part of the nose and the lower wall of the orbital foramen provided comparable results to the standard technique and showed adequate reproducibility. Other reference areas that have been used so far in the literature were less reliable. Within the limitations of the study, a valid superimposition reference area for serial 3D facial images of growing individuals is suggested. The method has potential to greatly expand the possibilities of this highly informative, risk free, and easily obtained 3D tool for the assessment of facial changes in growing individuals.

Evaluations of the facial attractiveness of young women with severe maxillary anterior crowding by orthodontists and laypeople with and without orthodontic treatment experience in Japan

INTRODUCTION

Maxillary anterior crowding (MxAC) has been considered to be an esthetically favorable characteristic of young women in Japan. It has been hypothesized that laypeople and orthodontists have different esthetic preferences; however, to date, this has not been investigated in detail. Therefore, the present study compared the facial attractiveness of women with MxAC and the interpretation of MxAC among orthodontists and laypeople with and without orthodontic treatment experience in Japan.

METHODS

Thirty-eight orthodontists, 42 laypeople with orthodontics (patients), and 43 laypeople without orthodontics (laypeople) evaluated the attractiveness of resting and smiling frontal images of 12 women with MxAC (MxAC models; mean age, 21.7 ± 2.6 years) and 12 women with normal occlusion (normal models; mean age, 20.1 ± 0.7 years) using a visual analog scale. In addition, they responded to a questionnaire that asked them to select the terms most closely associated with MxAC. All evaluators and models were Japanese.

RESULTS

For all evaluator groups, the facial attractiveness of the MxAC models was significantly lower than that of the normal models for both the resting and smiling images. For MxAC models, orthodontists evaluated resting images more attractive than smiling images, whereas laypeople evaluated smiling images more attractive than resting images. Significantly more patients and laypeople than orthodontists selected "cute" as the term most closely associated with MxAC (P <0.05).

CONCLUSIONS

The orthodontists, patients, and laypeople showed a different tendency in their facial attractiveness preferences. Regardless of their orthodontic experience, the laypeople showed more positive interpretations of MxAC than orthodontists. This finding seems to be influenced by Japanese culture, which values irregularity in nature as one form of beauty.

Cone beam computed tomography imaging of sagittal positions of the mandibular prominence and maxillary central incisors in adult Chinese Han men as an aesthetic profile determinant

BACKGROUND

To analyze the sagittal positions of the mandibular prominence and maxillary central incisors in adult Chinese Han men to establish their aesthetic profile characteristics.

METHODS

Seventy-four Chinese Han men aged 18 to 40 years underwent cone beam computed tomography for detecting the distances between Glabella and Subnasale, Subnasale and Menthon of soft tissue, Condyle and Gonion, Pogonion and Pogonion's Anterior Limit Line, Facial Axis point of maxillary central incisor and the Goal Anterior Limit Line as well as the angle of the Occlusal Plane. Dolphin Imaging and Photoshop software packages were used to generate silhouette profiles. Thirteen orthodontists assessed the silhouette profiles and assigned visual analog scale scores. Scores >70 were assigned to the aesthetic (group 1), scores of 60to 70 to the general (group 2), scores of 50 to 60 to the acceptable (group 3), and scores of <50 to the unaesthetic profile (group 4).

RESULTS

A total of 15 men were assigned to group 1, 35 to group 2, 14 to group 3, and 10 to group 4. There were no significant differences in the variables examined between groups 1, 2, and 3, but comparing group 1 with group 4, Pogonion and Pogonion's Anterior Limit Line (1.16 ± 2.61 mm vs -1.44 ± 2.92 mm, P = .046) and Facial Axis-Goal Anterior Limit Line (-0.61 ± 2.54 mm vs 1.70 ± 2.62 mm, P = .038) there were significant differences.

CONCLUSION

Compared with the unaesthetic profile group, the sagittal positions of the maxillary central incisors were slightly posterior, and the chin was slightly anterior in adult Chinese Han men with an aesthetic profile.

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.

Perspective Morphometric Criteria for Facial Beauty and Proportion Assessment

Common sense usually considers the assessment of female human attractiveness to be subjective. Nevertheless, in the past decades, several studies and experiments showed that an objective component in beauty assessment exists and can be strictly related, even if it does not match, with proportions of features. Proportions can be studied through analysis of the face, which relies on landmarks, i.e., specific points on the facial surface, which are shared by everyone, and measurements between them. In this work, several measures have been gathered from studies in the literature considering datasets of beautiful women to build a set of measures that can be defined as suggestive of female attractiveness. The resulting set consists of 29 measures applied to a public dataset, the Bosphorus database, whose faces have been both analyzed by the developed methodology based on the expanded set of measures and judged by human observers. Results show that the set of chosen measures is significant in terms of attractiveness evaluation, confirming the key role of proportions in beauty assessment; furthermore, the sorting of identified measures has been performed to identify the most significant canons involved in the evaluation.

Association of facial sagittal and vertical characteristics with facial aesthetics in the Northern Finland Birth Cohort 1966

OBJECTIVE

To explore the association of facial sagittal and vertical dimensions with aesthetic assessment by three panel groups.

MATERIALS AND METHODS

The study population comprised adult individuals from the Northern Finland Birth Cohort 1966 (NFBC1966). A clinical oral examination including digital facial photographs was performed. The study population was divided into subjects with the lowest and highest values in soft tissue measurements in lower anterior facial height percentage (LAFH%) (60 subjects) and antero-posterior jaw relationship [soft tissue A-point, nasion, and B-point (ANB) angle; 60 subjects] and a control group (30 subjects). Frontal and profile facial photographs were presented to three panel groups: five orthodontists, five dentists, and five laypersons, who evaluated the photographs using the visual analogue scale (VAS).

RESULTS

This study showed significant differences in VAS mean scores between the panel groups. Curve estimation revealed a significant quadratic association between aesthetic VAS evaluation and ANB angle for all panel groups. The association between ANB angle and perceived facial attractiveness was highest among orthodontists (R2 = 0.276, P = 0.001 for males; R2 = 0.285, P = 0.001 for females). However, no statistically significant association was found between facial attractiveness and LAFH%.

CONCLUSION

Facial sagittal dimensions appeared to influence facial aesthetics more than vertical dimensions in middle-aged adults. In their perception of facial aesthetics, orthodontists were more influenced by antero-posterior jaw relationships than dentists and laypersons. The overall perception of facial attractiveness related to facial dimensions appeared to differ between the panel groups in female and male faces.

Hakeem M, Yamaki M. Perception of dental professionals and lay people to altered facial esthetics

Introduction

The aim of this study was to examine whether dental professionals and lay people group do agree in their perception of digitally altered facial components or not.

Materials and Methods

A frontal photograph of a Saudi young man was taken, imported, and digitally altered to a series of images of 16 photographs. Eyes, nose, mouth, and chin were altered gradually from the original photograph and were rotated 1°, 3°, and 5°. 225 raters (60 lay people, 41 orthodontists, 77 dentists, and 47 dental students) were invited and asked to evaluate the original and altered images using a visual analog scale.

Results

Lay people were less critical and gave higher ratings than dentists when evaluating rotated eyes of 5°. Orthodontists gave higher ratings than lay people and dental students at distinguishing of 1° of rotated nose. Orthodontists were less critical in rating larger alterations of the nose at 3° than lay people. Orthodontists were also less discriminating of minor alterations of the lips. They could not detect mouth rotation of 1° compared to lay people and dental students.

Conclusions

The results of this study underline the importance of developing an objective index to enumerate the magnitude of facial asymmetries.

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.

Differences in Lip Support with and without Labial Flanges in a Maxillary Edentulous Population. Part 2: Blinded Subjective Analysis

PURPOSE

To study the subjective differences in facial esthetics evaluations among lay people, general dentists, and prosthodontists, when evaluating images of patients wearing a maxillary denture with a labial flange in comparison to an experimental flangeless denture.

MATERIALS AND METHODS

A random sample of 20 maxillary edentulous patients from the original sample of 31 patients described in part 1 of the study was selected for this study. A total of 60 judges comprising 15 general dentists, 15 prosthodontists, and 30 lay people were recruited for subjective analysis. The judges were blinded about the objectives of the study and were asked to rate the facial esthetics of each image using a 100 mm visual analog scale (VAS) instrument. Four digital images per subject (total of 80 images) were evaluated in a random order, twice by all 60 judges. A repeated measures general linear mixed modeling method using restricted maximum likelihood estimation was performed using mixed procedure in a statistical software package to study the differences in evaluations.

RESULTS

The overall VAS ratings of facial esthetics for images with flangeless dentures were slightly lower compared to images with labial flanges, and this difference was statistically significant (p < 0.05). This was true for both profile and frontal images; however, the magnitude of the difference was too small (no greater than 4 mm on a 100 mm scale) to be clinically significant. There were no statistically significant differences in facial esthetics ratings irrespective of the background or gender of the judges.

CONCLUSIONS

Flangeless dentures resulted in slightly lower ratings of facial esthetics compared to images with a labial flange, but the differences were clinically insignificant. This was true for all judges comprising general dentists, prosthodontists, and lay people and for both frontal and profile images.

Comparison between the Visual Analog Scale and the Numerical Rating Scale in the perception of esthetics and pain

BACKGROUND

Pain is an unpleasant, emotional, and sensorial experience. Esthetics and pain express perceptions or sensations that are subjective and personal, but non-consensual, between professionals and patients. The Visual Analog Scale (VAS) and the Numerical Rating Scale (NRS) are simple methods to evaluate such subjective phenomena.

OBJECTIVE

To verify whether a concordance exists between VAS and NS in the perception of esthetics and pain.

MATERIAL AND METHODS

Regarding esthetics, an on-line questionnaire was prepared with extra- and intra-oral images (adapted). The order of the scales was alternated between interwoven and sequential. Regarding perception of pain, respondents personally classified its intensity at the present moment, or over the past 30 days.

RESULTS

A statistically significant concordance (P<0.001) - positive and moderate - was found between the scales, for the evaluation of both the extra- and intra-oral images, r=0.678 and 0.638, respectively. Regarding pain perception, taking formal education into account, no concordance was found between the two scales for participants who had "no formal education" (P>0.05). The concordance between the scales increased proportionally with the level of education.

CONCLUSION

There was a concordance between the scales with regard to esthetical perception and the evaluation of pain. When assessing esthetics, the order in which the two scales are applied does not affect the concordance between them. However, the strength of the concordance is influenced. Esthetic perception is not influenced by the differences between the panels of evaluators. The concordance between the two scales, for the evaluation of pain, increases proportionally with the level of formal education.

Differences in Lip Support with and without Labial Flanges in a Maxillary Edentulous Population. Part 4: Patient-Centered Analysis

PURPOSE

To study the subjective differences in facial esthetics evaluations and the ability to distinguish facial changes due to changes in lip support, when evaluated by patients themselves. An additional objective was to study the differences between patients' self-evaluation versus evaluation of other patients.

MATERIALS AND METHODS

A total of 22 maxillary edentulous patients from the original sample of 31 patients described in Part 1 of the study, returned to participate in this part of the study. The 22 patients acted as judges for all images in this study, and were therefore un-blinded to the objectives and details of the study. Patients first completed evaluation of facial esthetics on a visual analog scale (VAS). Four digital images per patient (total of 88 images) were evaluated in a random order, twice by all 22 patients. The mean scores from all judgments were used as the outcomes to be analyzed. All patients then took a discriminatory sensory analysis test (triangle test) where they were required to correctly identify the image with a flangeless denture out of a set of 3 images. Both the VAS and triangle test ratings were conducted twice in a random order, and mean ratings were used for all analyses.

RESULTS

For VAS analysis, there were no statistically significant or clinically significant differences in facial esthetics ratings between flange and flangeless dentures (p < 0.05). This was true for both profile and frontal images, irrespective of self-evaluation versus evaluation of other patients, years of patient edentulism, and judge (patient) gender. For the triangle test, frontal images had a correct identification rate of 50.2% and profile images of 50.4%, and the difference was not significant. There were no significant differences in triangle test results with respect to self-evaluation versus evaluation of other patients and judge (patient) gender. For all patients, the likelihood of correctly identifying images with flangeless dentures was significantly greater than 1/3, which was the minimum chance for correct identification (p < 0.0001).

CONCLUSIONS

Flangeless dentures resulted in no differences in facial esthetics ratings for frontal and profile images, when evaluated by patients. When patients were forced to look for differences, flangeless dentures were detected in half of the image sets. These findings were similar for self-evaluation versus evaluation of other patients and for both patient genders.

Three-Dimensional Anthropometric Database of Attractive Caucasian Women: Standards and Comparisons

The aim of this paper is to develop a database to determine a new biomorphometric standard of attractiveness. Sampling was carried out using noninvasive three-dimensional relief methods to measure the soft tissues of the face. These anthropometric measurements were analyzed to verify the existence of any canons with respect to shape, size, and measurement proportions which proved to be significant with regard to the aesthetics of the face. Finally, the anthropometric parameters obtained were compared with findings described in the international literature.

The study sample was made up competitors in the Miss Italy 2010 and 2009 beauty contest. The three-dimensional (3D) scanning of soft tissue surfaces allowed 3D digital models of the faces and the spatial 3D coordinates of 25 anthropometric landmarks to be obtained and used to calculate linear and angular measurements. A paired Student t test for the analysis of the means allowed 3 key questions in the study of biomorphometric parameters of the face to be addressed through comparison with the data available in the literature.

The question of statistical evidence for the samples analyzed being members of the populations samples reported in literature was also addressed.

The critical analysis of the data helped to identify the anthropometric measurements of the upper, middle, and lower thirds of the face, variations in which have a major influence on the attractiveness of the face. These changes involve facial width, height, and depth. Changes in measurements of length, angles, and proportions found in the sample considered were also analyzed.

Alveolar and Skeletal Chin Dimensions Associated with Lower Facial Height Among Different Divergent Patterns

INTRODUCTION

Alveolar and skeletal chin dimensions with facial height have an impact on diagnosis and treatment planning in orthodontic patients and serves as a reference landmark for facial aesthetics.

AIM

To evaluate the alveolar and skeleton chin dimensions among different divergent patterns, to evaluate the lower face height in different divergent growth patterns, to give an estimate to the oral surgeon for any adjunctive procedure.

MATERIALS AND METHODS

The study includes a total sample of 45 non-growing individuals (26 males and 19 females) from the archival records of the Orthodontic Department with age ranging between 18-25 years, classified into different divergent patterns based on the mandibular plane angle. The sample was divided into three groups, of which 15 patients in each group were evaluated: Group-1: Normodivergent, Group-2: Hypodivergent and Group-3: Hyperdivergent patterns respectively. Standardized digital lateral cephalograms and antero-posterior cephalograms of these patients were obtained in Natural Head Position (NHP).

RESULTS

The results of the retrospective cephalometeric study were statistically analyzed by using ANOVA and Tukey's multiple post hoc test which showed that hard tissue chin measurement were greater in hypodivergent group (13.7mm) and the increased lower facial height showed statistically significant difference in high mandibular plane angle group (59.6mm). In antero-posterior cephalograms the transverse width showed statistically significant difference in normodivergent group (32.60mm).

CONCLUSION

The anterio-posterior width of the symphysis was higher in hypodivergent growth pattern, whereas vertical height of the symphysis was greater in hyperdivergent group. The lower facial height among three groups showed statistically significant difference among hyperdivergent group. In comparison of all the three groups in Anterio-Posterior (AP) cephalograms, statistically significant difference was noted in normodivergent group when compared with the other two groups.

Relationship between perception of malocclusion and the psychological impact of dental aesthetics in university students

Introduction and Objectives: The objectives were to assess the relationship between perceived smile aesthetics and perceived psychological impact as measured by the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ), and their own perception of it using the Aesthetic Component of the Index of Orthodontic Treatment Need (IOTN-AC) and a Visual Analog Scale (VAS); relate the IOTN-AC and VAS to the PIDAQ; and study the predictive capacity of the scales for psychological impact. Material and Methods: A cross-sectional study was conducted in 447 college students in Spain and Portugal (average age 20.4 years, 33.1% men and 66.9% women). The online self-completed surveys used the recently-validated Spanish and Portuguese versions of the PIDAQ to assess the self–reported psychological impact of the students’ dental aesthetics and IOTN-AC and an ad hoc 100 mm VAS for their perception of their dental aesthetics. Results: PIDAQ was linearly correlated with IOTN AC and VAS. Pearson’s coefficient was 0.55 for PIDAQ and IOTN-AC (CI 95% 0.48-0.61) and -0.72 for PIDAQ and VAS (CI 95% -0.66 - -0.76). VAS and IOTN-AC were predictive variables in a linear regression model of the total PIDAQ score. The VAS diagnosed individuals whose dental aesthetics had a self-perceived psychological impact (area under the curve 0.827, CI 95% 0.787-0.868) more precisely than the IOTN-AC (area under the curve 0.742, CI 95% 0. 696-0.788). Conclusions: In adults patients, there is a significant linear relationship between perceived smile aesthetics and self-perceived psychological impact.

Key words:Visual Analog Scale, Index of Orthodontic Treatment Need, malocclusion, psychological, aesthetics.

How does variation in lower anterior face height influence perceived attractiveness? A quantitative investigation

OBJECTIVE

The purpose of this investigation was to undertake an objective and quantitative evaluation of how severity of lower anterior face height (LAFH) variations influences perceived attractiveness.

DESIGN

Cross-sectional study

SETTING

St George's Hospital, London, UK PARTICIPANTS AND METHODS: The LAFH of an idealized male and female frontal facial image were altered in 2·5 mm increments from -20 to 20 mm (male images) and from -10 to 20 mm (female images), in order to represent reduction and increase in height of this region. These images were rated by a pre-selected group of pre-treatment orthognathic patients (n = 75), clinicians (n = 35) and laypersons (n = 75).

OUTCOME MEASURES

Ratings on a seven-point Likert scale.

RESULTS

With an increase in LAFH, desire for surgery became significant at 15-16 mm for male faces and 13-14 mm for female faces. With a reduction in LAFH, desire for surgery became significant at -14 to -17 mm for male faces; a smaller reduction of -6 to -8 mm led to a significant desire for surgery for female faces.

CONCLUSIONS

The classical vertical facial trisection canon of upper face height as one-third (33·3%), midface height as one-third (33·3%) and LAFH as one-third (33·3%) of total anterior face height may be used as an 'ideal' proportional ratio. Mild LAFH variations were largely acceptable. In terms of the percentage LAFH to total anterior face height (TAFH) and anterior face height (AFH), observers did not desire surgery for LAFH variations of 25-42% of TAFH (40-66% of AFH) for male faces, and 28-42% of TAFH (45-66% of AFH) for female faces.

Influence of chin height on perceived attractiveness in the orthognathic patient, layperson, and clinician

OBJECTIVE

To determine an objective and quantitative evaluation of how severity of chin height variations influence perceived attractiveness.

MATERIALS AND METHODS

The chin height of an idealized male and female frontal facial image was altered in 2.5-mm increments from -12.5 to 22.5 mm (male images) and from -10 to 20 mm (female images). These images were rated on a seven-point Likert scale by a preselected group of pretreatment orthognathic patients, clinicians, and laypeople.

RESULTS

The classical lower facial proportional canon of upper lip height as one third (33.3%), lower lip height as one third (33.3%) and chin height as one third (33.3%) of lower anterior face height (LAFH) may be used as an "ideal" proportional ratio. However, chin height variations within a given proportional range are largely unnoticed, ie, from approximately 30% chin height in relation to LAFH (male and female) up to approximately 40% (males) and 50% (females) chin height in relation to LAFH. Additionally, surgery is only desired with greater variations in chin height: greater than 50% and less than 20%-23% of LAFH in males, and greater than 58% and less than 20%-22% of LAFH in females. Patients and clinicians are more critical than laypeople, but no significant differences were found between clinicians and patients.

CONCLUSIONS

In relation to the classical canon, surgical correction of chin height deformities are desired with chin height greater than 50% and less than 20%-23% of LAFH in males, and greater than 58% and less than 20%-22% of LAFH in females.

Evaluation of facial esthetics by a panel of professionals and a lay panel

The daily business of every orthodontist is to correct malocclusions and the patient's accompanying unesthetic appearance, thus enhancing his/her social integration and boosting their self-esteem. Consequently, we considered it necessary to have the facial esthetics of the Moroccan population assessed by two panels, one a lay group representing the general public, the other a panel of professionals. We conducted a transverse descriptive inquiry on 100 students from the Casablanca School of Dental Medicine. Views showing the full face, profile and three-quarters smile were submitted for evaluation by the lay and professional panels. Statistical comparison showed a significant correlation between the two panels. Cephalometric findings of the eight cases judged to be the most attractive were compared with Steiner analysis and showed concordance for the majority of the measurements studied. Likewise, comparison of the opinions of the male and female sections of the panels demonstrated significant concordance.