A preliminary study on the key factors contributing to the attractive lips of Chinese children

Impact of facial components on the attractiveness of face: A perception-based study

INTRODUCTION

Magazines and television displays are not merely crammed with faces-they are filled with appealing faces, and both men and women are interested in a suitable partner's appearance. This study investigated what makes a face attractive and whether perception-related differences exist between facial attractiveness and facial components.

METHODS

In this descriptive-analytical study, frontal and lateral view photographs of 18 young adults (9 male and 9 female) in Class I, II, and III malocclusions were assessed by 90 orthodontists, dentists, models, and laypeople using a 7-point Likert scale in terms of attractiveness. Based on scores, attractive and unattractive groups were formed. Using image analysis software, a range of defined length, angles, perimeter, and area for lips, nose, and chin were measured for the attractive group. For statistical analysis, each group was compared using a 1-way analysis of variance. Logistic regression was performed to analyze the factors of different parameters to the attractiveness of facial components.

RESULTS

Overall full-face width, upper lip angle, lip area, and mentolabial angle was significantly different in all the 3 classes (P ≤0.05). In Class I malocclusion, nasolabial angle among orthodontists, nasofrontal angle among dentists, lower lip among models, and full-face width among laypeople were responsible for facial attractiveness variation. In Class II malocclusion, nose to upper lip among orthodontists, Cupid's bow among dentists, wider face among models, and upper lip among layperson were responsible for variation in facial attractiveness. In Class III malocclusion, lower lip angle among orthodontists and dentists, Cupid's bows among models and layperson was responsible for variation in facial attractiveness.

CONCLUSIONS

In Class I faces, lips (Cupid's bows, lower lips, lip areas), nose (nasolabial, nasofrontal, and nasomental angles), and chin (lower lip to chin) contributed to the overall attractiveness of the face, while in Class II faces, lips (upper lip length, interbow distance, lower lip angle), nose (full facial convexity), and chin (mentolabial sulcus), as well as a greater full-face width contributed to the overall attractiveness of the face. In Class III faces, lips (lower lip angle, upper lip length), nose (nose tip angle, full facial convexity), and chin (mentolabial sulcus depth) contributed to the overall attractiveness of the face.

Lip Shapes Over the Last Century (1948-2012)

The aim of this study was to analyze lip shapes as represented in the British edition of Vogue over the last century (1916-2015). Photographs containing distinguishable lips were selected from a book entitled Vogue 100: A Century of Style. A total of 98 frontal pictures (20 males, 78 females) in which the lips and mouth were identifiable were included and analyzed in terms of 4 lip-related ratios (lip thickness-to-width ratio [LTW]; upper-to-lower vermillion ratio [ULR]; upper vermillion thickness-to-upper lip height ratio [VUL]; and lip-to-nose width ratio [LNW]). The LTW was 0.39 ± 0.07, and did not vary significantly over time (P = 0.261 [linear regression analysis]). The LTW of women (0.41 ± 0.07) was significantly greater than that of men (0.34 ± 0.05) (P < 0.001 [independent 2-samples t-test]). The ULR was 0.74 ± 0.16, and did not vary significantly over time (P = 0.647). There was no significant difference in the ULR between men (0.75 ± 0.10) and women (0.74 ± 0.17) (P = 0.769). The VUL was 0.43 ± 0.09, and did not vary significantly over time (P = 0.550). The VUL of women (0.44 ± 0.09) was significantly greater than that of men (0.37 ± 0.06) (P = 0.001). The LNW was 1.49 ± 0.19, and did not vary significantly over time (P = 0.619). There was no significant difference in the LNW between men (1.43 ± 0.16) and women (1.51 ± 0.19) (P = 0.082). The results of this study may be useful for planning facial rejuvenation operations, as well as for clinical practitioners dealing with brow esthetics or lip tattooing.

An automatic approach for classification and categorisation of lip morphological traits

Classification of facial traits (e.g., lip shape) is an important area of medical research, for example, in determining associations between lip traits and genetic variants which may lead to a cleft lip. In clinical situations, classification of facial traits is usually performed subjectively directly on the individual or recorded later from a three-dimensional image, which is time consuming and prone to operator errors. The present study proposes, for the first time, an automatic approach for the classification and categorisation of lip area traits. Our approach uses novel three-dimensional geometric features based on surface curvatures measured along geodesic paths between anthropometric landmarks. Different combinations of geodesic features are analysed and compared. The effect of automatically identified categories on the face is visualised using a partial least squares method. The method was applied to the classification and categorisation of six lip shape traits (philtrum, Cupid’s bow, lip contours, lip-chin, and lower lip tone) in a large sample of 4747 faces of normal British Western European descents. The proposed method demonstrates correct automatic classification rate of up to 90%.

Perceptions of Attractive and Healthy-Looking Lips

The aim of this study was to characterize Koreans' perceptions of attractive and healthy-looking lips.A survey was conducted among 258 women and 72 men who were asked to view illustrations of various examples of the 4 lip-related ratios (lip thickness-to-width ratio [LTW]; upper-to-lower vermillion ratio [ULR]; upper vermillion thickness-to-upper lip height ratio [VUL]; and lip-to-nose width ratio [LNW]) and to choose which they thought were attractive or healthy-looking.The LTW ratios most often identified as attractive were LTW-1/3 (lip thickness is 1/3 of lip width, 40.0%) and LTW-2/5 (47.3%). The LTW value most often identified as healthy-looking was LTW-2/5 (54.3%). The most attractive ULR ratio was ULR-4/5 (upper vermillion thickness is 4/5 of the lower vermillion, 49.4%). The most healthy-looking ULR ratio was ULR-4/5 (47.0%). The most attractive VUL ratio was VUL-1/2 (thickness of the upper vermillion is 1/2 of upper lip height, 60.3%). The most healthy-looking VUL ratio was VUL-1/2 (61.0%). The most attractive LNW ratio was LNW-3/2 (lip width is 3/2 of nose width, 42.1%). LNW-3/2 was also the most preferred in all age groups below 50 years, while those over 50 preferred LNW-4/3 (55.0%). The most healthy-looking LNW ratios were LNW-3/2 (35.2%) and LNW-4/3 (32.1%). LNW-3/2 was the most preferred in all age groups below 50, while those over 50 preferred LNW-4/3 (40.0%). It therefore seems that older people preferred a narrower lip width than younger people.The results of this study can be applied in lip augmentations or aesthetic lip surgery.