The Esthetic Difference of Chinese Beauty Evaluated by Two Different Human Races Based on Three-Dimensional Average Face Analysis

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.

Average Three-Dimensional Skeletofacial Model as a Template for Bone Repositioning during Virtual Orthognathic Surgery

BACKGROUND

Virtual planning has revolutionized orthognathic surgery. This study presents a computer-assisted method for constructing average three-dimensional skeletofacial models that can be applied as templates for surgical planning for maxillomandibular repositioning.

METHODS

The authors used the images of 60 individuals (30 women and 30 men) who had never undergone orthognathic surgery to construct an average three-dimensional skeletofacial model for male participants and one for female participants. The authors validated the accuracy of the newly developed skeletofacial models by comparing their images with 30 surgical simulation images (ie, skulls) that had been created using three-dimensional cephalometric normative data. The comparison was conducted by superimposing surgical simulation images created using the authors' models with the previously created images to analyze their differences, particularly differences in the jawbone position.

RESULTS

For all participants, the authors compared the jaw position in the surgical simulation images created using the authors' average three-dimensional skeletofacial models with that in the images created using three-dimensional cephalometric normative data. The results revealed that the planned maxillary and mandibular positions were similar in both images and that the differences between all facial landmarks were less than 1 mm, except for one dental position. Most studies have reported less than 2 mm to be the success criterion for the distance difference between planned and outcome images; thus, the authors' data indicate high consistency between the images in terms of jawbone position.

CONCLUSION

The authors' average three-dimensional skeletofacial models provide an innovative template-assisted orthognathic surgery planning modality that can enhance the fully digital workflow for virtual orthognathic surgical planning.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

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.

Does 3-dimensional facial attractiveness relate to golden ratio, neoclassical canons, 'ideal' ratios and 'ideal' angles?

Background

The established recommendations and guidelines regarding ideal measurements for an attractive face are mostly based on data gathered among Caucasian population. The aim of this study was to examine the relationship between perception of 3-dimensional facial attractiveness and golden ratio, neoclassical canons, ‘ideal’ ratios and ‘ideal’ angles in Hong Kong Chinese.

Methods

Thirty 3-D photographs (15 males and 15 females) were shown to 101 laypersons and 60 patients seeking orthognathic treatment. The photographs were rated based on a 100 mm visual analogue scale (VAS) from 0 (very unattractive) to 100 (very attractive).

Results

More than half of the measurements (42/77) in females and thirty-two measurements in males were found to be significantly different from the ideal target value (p < 0.05) upon the comparison of the attractive faces with golden ratio, neoclassical canons, ‘ideal’ ratios and ‘ideal’ angles. Meanwhile, correlation tests between VAS scores and the parameters detected significant results (p < 0.05) in only six ratios, eight angles, one neoclassical canon and one proportion.

Conclusions

Despite several renowned ‘ideal’ parameters of attractive faces that have been recommended in the literature, only a few of them were found to be significantly correlated with attractive faces in Hong Kong Chinese.

Surgical Versus Nonsurgical Lower Face Contouring: Layperson Perceptions of Attractiveness and Personality Traits

BACKGROUND

Traditional approaches to lower face contouring involve ostectomy of the mandibular angle or body. More recently, nonsurgical techniques have gained popularity, including neurotoxin injection to the masseter muscle. This study aims to evaluate layperson perceptions of patient attractiveness and personality traits following lower face contouring using either surgical or nonsurgical treatment.

METHODS

In this survey study distributed via Amazon's Mechanical Turk, respondents viewed a series of 14 patient images obtained in clinic before and after surgical or nonsurgical jawline slimming, or without any facial aesthetic procedure. Respondents rated changes in attractiveness and personality trait scores between the before and after image (score: -50 to 50, with 50 representing the greatest posttreatment increase and 0 representing no change). We used descriptive statistics and multivariable regression to determine differences in respondent ratings between patient images.

RESULTS

A total of 415 respondents (mean age 38 years, 50.6% female) successfully completed the survey. Compared to patients who underwent nonsurgical treatment, those who received surgery had significantly greater increases in perceived attractiveness (P < 0.001), femininity (P < 0.001), friendliness (P < 0.001), intelligence (P < 0.001), trustworthiness (P < 0.001), financial wealthiness (P < 0.001), dominance (P < 0.01), and self-esteem (P < 0.001). Gonial angles increased and jaw widths decreased following both surgical and nonsurgical intervention, with no statistically significant difference between treatment groups.

CONCLUSIONS

From the layperson perspective, surgical compared to nonsurgical jawline contouring offers greater improvements in perceptions of attractiveness and favorable personality traits.

Accuracy of individualized 3D modeling of ossicles using high-resolution computed tomography imaging data

Background

The present study aimed to investigate the visibility of small ossicle parts/landmarks on high-resolution computed tomography (HRCT)/3D reconstruction (3D) to investigate what improvements in scanning resolution are needed before accurate 3D printing of patient-specific ossicles is possible.

Methods

A total of 24 patients with sudden deafness sought consultation at the Department of Otorhinolaryngology Head and Neck Surgery at the Sixth Medical Center of People's Liberation Army General Hospital between October 2013 and June 2014 were enrolled in the study. All participants underwent a 256-slice spiral HRCT temporal bone axial scan, yielding a Digital Imaging and Communications in Medicine documents series. These documents were then inputted into Mimics 16.0 interactive medical image processing software for data conversion and the creation of 3D segmentation and visualizations of the ossicles. Finally, the 3D images were compared using multiplanar reformation (MPR) and 3D volume-rendering (VR) reconstructed images of ossicles to verify their consistency. These were then compared with the normal ossicle structure to evaluate the accuracy of the restoration.

Results

The findings indicated that the morphology of the ossicles from the converted Mimics 16.0 data achieved a display rate of ≥90% when used to display 7 landmarks (the caput mallei, collum mallei, processus lateralis mallei, manubrium mallei, corpus incudis, crus longum incudis, and crus breve incudis). This demonstrates excellent matching with the images of ossicles obtained from MPR and 3D VR reconstruction. Kappa consistency testing found that the κ-value was higher than 0.75. When displaying the lenticular process, caput stapedis, crus anterius stapedis, and crus posterius stapedis landmarks. The display rate was around 60%, which shows good matching with the ossicles' images obtained from MPR and 3D VR reconstruction, with a κ-value >0.4. However, the display rate of the stapes footplate was only 25%, showing greater differences with the images obtained from MPR (76.4%) and 3D VR reconstruction (52.8%), with a κ-value <0.4.

Conclusions

The accuracy of the visualization of the malleus and incus after restoration via Mimics 16.0 software, based on temporal bone HRCT data, was high, and the degree of restoration was good. However, the accuracy and degree of restoration of the stapes footplate require further improvement.