Effect of lower facial height and anteroposterior lip position on esthetic preference for Korean silhouette profiles

Analysis of maxillary teeth and soft tissue profiles among Tibetan and Han Chinese females with facial symmetry for orthodontic treatment planning

The evaluation of maxillary teeth and soft tissue profiles is a critical component of orthodontic diagnosis and treatment planning. This study aimed to evaluate the correlation between the sagittal position of maxillary anterior teeth and facial profile esthetics among Tibetan and Han Chinese adult females for optimizing orthodontic diagnosis and treatment planning. A total of 100 Tibetan Chinese and 100 Han Chinese adult females with good facial symmetry were recruited. The smiling facial profile images with the maxillary central incisors and forehead in full view were taken based totally on the same standard. The photo measurement and head position were adjusted using the picture-enhancing software. The reference traces associated with forehead inclinations were utilized to assess the anteroposterior (AP) positions of the maxillary central incisors. The results showed that a round forehead was the dominant forehead shape for Tibetan (93%) and Han (55%) Chinese females. In Tibetan females, 85% of the maxillary central incisors were found to be located between the forehead's anterior limit line (the Gall line) and the goal anterior limit line (the Fall line), with 15% located posterior to the Fall line. This distribution manifested a strong association with incisor position and forehead inclination (R2  = 0.742). In Han females, 83% of the maxillary central incisors were located between the Fall line and the Gall line, with 12% posterior to the Fall line and 5% anterior to the Gall line. The positions of the maxillary central incisors exhibited a strong relationship with forehead inclination (R2  = 0.827). The maxillary central incisors were close to the aesthetic line in both ethnic groups, while forehead inclinations were correlated with AP maxillary incisor position. These findings demonstrated that there was a close relationship between the incisor position of Tibetan and Han females with facial symmetry and the forehead FFA factor, indicating a reference in oral hard and soft tissues for optimizing orthodontic diagnosis and treatment planning in terms of facial contour.

Assessment of the Acceptable Range of Lips and Chin Position in Two Different Geographical Zones of Iran among Laypersons

Statement of the Problem

The position of the chin and lips are important components in the lower third of the face and can be changed by orthodontic treatment. It seems that factors such as diversity in culture, ethnicity, and place of residence are among the factors affecting people's perception of beauty. Iran, as a vast country, contains different ethnicities and cultures, and of course, it is not exempt from this point of view.

Purpose

Our purpose of conducting this study is to investigate the impact of the difference in living environment and culture on people's aesthetic perception. Orthodontists and oral surgeons can use these data to choose the best treatment plan for the patients according to their geographical zones.

Material and Method

A descriptive cross-sectional study was conducted to evaluate the perception of lips and chin position. A series of 25 profile images were prepared in 5 sets. Each set contained 5 profile images. Northern and Southern lay people and orthodontists were asked to evaluate the profile series of each set in 1 session and score them from 1 to 5: 1, very unattractive; 2, unattractive; 3, neither attractive nor unattractive; 4, attractive; or 5, very attractive.

Results

652 participants in 3 groups, including 16 orthodontists (10 men and 6 women), 318 lay people of the North of Iran (172 men and 138 women), and 318 lay people of the South of Iran (175 men and 139 women) participated in this study. Regardless of the chin position, normal lip position and slight changes of that (in both protruded and retruded positions) were more favorable for all three groups. The images with moderately retruded lips were scored as the least attractive by all three groups and orthodontist gave the lowest score to these profiles. Southern people could better tolerate moderately retruded lips than other two groups. In the fifth series, orthodontists preferred slightly and moderately protruded lips in comparison to other two groups of laypeople.

Conclusion

Regardless of the chin position, normal and slightly (-2mm to +2mm) protruded and retruded lips were more favorable in all three groups. Southern people could better tolerate moderately retruded lips than the two other groups.

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.

A cross-sectional study: correlation of forehead morphology and dentoskeletal malocclusion in Chinese people

BACKGROUND

The lateral profile is an important indicator of facial attractiveness. This study explored the general characteristics of the forehead profile and protrusion, and their relationship with related factors in structure and development.

METHODS

Four hundred fourteen Chinese participants in the Yangtze River Delta region were involved. Including 206 males (17.15 ± 7.68 years old) and 208 females (18.35 ± 8.06 years old); 94 children (8.54 ± 2.21 years old, ranging from 4 to 12 years old), 166 adolescents (14.83 ± 1.50 years old, ranging from 13 to 17 years old), and 154 adults (25.52 ± 4.89, 18 years or older). The frontal section of the forehead was used to explore its shape. The straight distance between the vertical line of the FH plane through the nasal root point and its parallel line, which is tangential to the forehead, indicates the forehead prominence. Frontal sinus width was measured using the method described by Mahmood.

RESULTS

The general shape of the forehead was straight and slightly bulged near the eyebrow arch in males but rounder in females. The average forehead protrusion in males was higher than that in females in adults. Significant differences in forehead protrusion between the dentoskeletal classifications and growth phases were notable. Frontal protrusion significantly correlated with frontal sinus depth, especially in males, adults, Class I, and those whose convex points were located in the lower section of the forehead.

CONCLUSIONS

Age, race, and sex affect the forehead protrusion and frontal sinus width. Forehead protrusion may be an indicator of dentoskeletal deformities in the early stage. And dentoskeletal deformities may impair the correlation between the frontal sinuses and forehead protrusion during development.

TRIAL REGISTRATION

This retrospective, cross-sectional study was reviewed and approved by the Research Ethical Committee (T2020008), and registered at ClinicalTrial.gov with an identified number (ChiCTR2100041913).

Influence of lip position on esthetics perception with respect to profile divergence using silhouette images

BACKGROUND

The aim of the study was to determine the facial divergence and lip position combinations that are most and least preferred, and to investigate whether age or gender has an impact on these preferences.

METHODS

The current investigation was carried out on a sample of 1077 individuals who were not experts in the field (253 men and 824 females). The research employed black silhouette photographs of profiles featuring different lip locations and profile divergences. The recruitment of participants was conducted in order to assess the attractiveness of the profiles, employing a Likert scale. The various positions of the lips and variations in facial profiles were thoroughly categorized. Results were analyzed using the Chi-square test.

RESULTS

The findings of the research demonstrated that aesthetic perceptions displayed diversity when considering different lip locations and profile divergences. It was shown that neutral lip positions were predominantly favored, accounting for approximately 40.2% of the total frequencies in the anterior diverging group. It is noteworthy to highlight the aesthetically pleasing features exhibited by those with the most prominent lip position, occurring at a frequency of 10.9% in straight-diverging group. In the posterior divergent group, the most protruded lip position, showed very attractive aesthetics with frequency (7.1%). Gender, age, region, and level of education had significant influence on aesthetic perception.

CONCLUSIONS

The variety of aesthetic preferences is influenced by the location of the lips and the divergence of the facial profile, resulting in different outcomes within the categories of anterior, straight, and posterior divergence. Clinicians are advised to customize the treatment regimen in order to correspond with the unique desires and preferences of the patient.

Esthetic preferences of orthodontists, dentists, and plastic surgeons for balanced facial profiles

PURPOSE

The aim of this investigation was to determine whether the facial esthetics of subjects rated as "attractive" can be related to specific cephalometric soft tissue parameters.

METHODS

The profile silhouettes of 100 subjects (45 males and 55 females) were rated by 60 esthetics specialists (20 orthodontists, 20 dentists, and 20 plastic surgeons) using a Likert scale, and 30 of the subjects were selected as being "attractive". The cephalometric measurements of the attractive group were then compared with norms for the general Caucasian population.

RESULTS

The effects of specific measured parameters on profile beauty grades were assessed using the median test, and the following variables were found to show significant correlations between the Caucasian norms and the attractive profile group: the ratio of the upper to lower face height (P = 0.011), the ratio of the subnasale - labrale inferius (Sn-Li) and labrale inferius - menton (Li-Me`) lines (P = 0.011), the distance between the chin and the subnasale perpendicular (P = 0.002), upper lip thickness (P = 0.021), soft tissue chin thickness (P = 0.021), vertical height ratio (P = 0.021), and nasolabial angle (P = 0.021).

CONCLUSION

A straight profile with a fuller and more protruded upper lip, a higher nasal tip, and a smaller lower facial third are considered to be the most attractive facial features, and may be useful for improvement of facial esthetics.

Regional influence on the aesthetic preference of different Mongolian profiles: A comparative study of assessors from Northeast and Mainland India

OBJECTIVE

The purpose of this study was to determine the aesthetic preferences of three different groups-layperson, dentists, and orthodontists, with different ethnic and geographical backgrounds from North-eastern and Mainland India, and to evaluate whether there is any difference in the perception of facial profile aesthetics. The influence of one's ethnic and regional origin in the perception of facial profile aesthetics was evaluated in two populations of different backgrounds using VAS scale.

MATERIALS AND METHODS

Facial profile photos of 2 Mongolian descendants, 1 man and 1 woman having Class I (normal) profile were digitized and modified, sagittally, to obtain 7 sagittal variations of each profile. A total of 7 profile images were obtained for each of the male and female models. The photos were ranked by 240 participants from an aesthetic point of view between a score of 1 (very unattractive) and 10 (very attractive). Repeated measures ANOVA was used for intra-group comparison whereas one-way ANOVA and Z-test were used for inter-group comparisons.

RESULTS

The Class I profile was the most preferred in both male and female profile photos by orthodontists of both the two populations, whereas the Class III profile (prognathic mandible) was considered the least attractive (P<0.05). North-eastern layperson and dentists preferred profiles with a slightly retrusive maxilla, while mainland layperson and dentists were tolerant to a protrusive profile (P<0.05).

CONCLUSION

The participants' perception regarding the Class I profile aesthetics were found to be similar. However, differences were observed in the profile preferences in people of different ethnicities and regions. Also, professional training was found to influence the perception of profile aesthetics.