Keloids are a benign dermal fibrotic disorder with features similar to malignant tumors. keloids remain a therapeutic challenge and lack medical therapies, which is partially due to the incomplete understanding of the pathogenesis mechanism. We performed single-cell RNA-seq of 28,064 cells from keloid skin tissue and adjacent relatively normal tissue. Unbiased clustering revealed substantial cellular heterogeneity of keloid tissue, which included 21 clusters assigned to 11 cell lineages. We observed significant expansion of fibroblast and vascular endothelial cell subpopulations in keloids, reflecting their strong association with keloid pathogenesis. Comparative analyses were performed to identify the dysregulated pathways, regulators and ligand-receptor interactions in keloid fibroblasts and vascular endothelial cells. Our results highlight the roles of transforming growth factor beta and Eph-ephrin signaling pathways in both the aberrant fibrogenesis and angiogenesis of keloids. Critical regulators probably involved in the fibrogenesis of keloid fibroblasts, such as TWIST1, FOXO3 and SMAD3, were identified. TWIST1 inhibitor harmine could significantly suppress the fibrogenesis of keloid fibroblasts. In addition, tumor-related pathways were activated in keloid fibroblasts and vascular endothelial cells, which may be responsible for the malignant features of keloids. Our study put insights into the pathogenesis of keloids and provides potential targets for medical therapies.

Background: Masseter reduction by botulinum neurotoxin A (BoNT-A) injection is a popular procedure in East Asia. Inappropriate injection can result in various complications. Objectives: The aim of this study was to develop an approach for comprehensively evaluating the lower facial structure based on the shape of the mandible angle, the thickness of the masseter, and the thickness of subcutaneous fat. Methods: Clinical profiles and standard ultrasound images were collected from patients seeking masseter BoNT-A injections. Lower facial structures were evaluated based on 3 aspects: mandible, masseter, and subcutaneous fat and skin. The mandibular angle was classified as extroverted, straight, or introverted. The starting point of the middle part of the masseter was recorded. The thickness of the deep inferior tendon, the superficial and deep belly of the superficial part of the masseter, and their contractility were measured. Overall thickness and the thickness of subcutaneous fat and skin were also measured. Results: Eighty-four masseters from 42 patients were included. Straight mandibular angles were the most common type of angle (48.81%), followed by introverted (26.19%) and extroverted angles (25.00%). The middle part of the masseter starts from 2.33 [0.36] cm (mean [standard deviation]) above the mandible edge, which is above the usual injection points. The superficial belly was thicker than the deep belly in both static and clenching states (P = .048, P = .001) and had greater contractility. The average overall thickness was 1.87 [0.29] cm. Conclusions: Comprehensive evaluation of the lower facial contour and structure based on ultrasound examination could be a reliable and replicable assessment approach. Level of Evidence: 4:

Background: Double eyelids are always considered crucial aesthetic symbols. Despite numerous studies conducted on the attractiveness of double eyelids, there remains a dearth of research on quantitative and morphological evaluation of ideal double eyelids. Objectives: In this we study aimed to investigate the optimal height and morphological characteristics of ideal double eyelids. Methods: Participants were presented with a total of 9 images, consisting of 1 single eyelid image and 8 double eyelid images, featuring 2 distinct shapes and 4 varied pretarsal shows. Respondents were instructed to assign scores ranging from 1 (least attractive) to 5 (most attractive) for each image. Subsequently, the scores for each image were analyzed based on population demographics, followed by the calculation of aesthetic metrics. Results: The whole cohort deemed images with a 2-mm fold to be more attractive than 1 mm (P < .001), followed by 3 mm and 0 mm (single eyelid), and finally, 4 mm. Morphologically, significant differences were found between images with the same pretarsal shows of 3 mm (P < .001) and 4 mm (P = .026). Most subgroup analysis results were aligned with those of the cohort, with gender being the most significant factor in distinguishing double eyelid aesthetics. Additionally, aesthetic characteristics of 2-mm folds were found to be comparable to appealing double eyelids in previous studies. Conclusions: In this study we validated the optimal heights and morphology of double eyelids, thereby addressing the existing gap in aesthetic studies on double eyelids. These findings hold significant implications for surgical planning, effect assessment, and other periocular procedures related to upper blepharoplasty. Level of Evidence: 4:

Background: Pretarsal rolls are a crucial aesthetic feature. Despite numerous studies conducted on periorbital aesthetics, there remains a dearth of research on the ideal pretarsal rolls. Objectives: This study aimed to investigate 4 aesthetic characteristics of ideal pretarsal rolls: presence, width, proportion, and morphology. Methods: Respondents (385, including 80 aesthetic specialists) were presented with 7 series of images of pretarsal rolls, including 2 series of pretarsal roll existence, 2 series of varying widths, 2 series of different ratios between pretarsal roll and palpebral fissure height, and 1 series about morphology. Participants were asked to rank each image within a given series from most attractive to least attractive. The rankings were then analyzed according to population demographics. Results: The majority of respondents deemed images with pretarsal rolls to be more aesthetically pleasing (P < .001) than those without such features. Additionally, pretarsal rolls with a width of 5 mm (P < .001), a ratio to palpebral fissure height of 0.5:1 (P < .001), and a crescent shape (P < .001) were perceived as the most attractive. Moreover, individuals aged 40 or younger exhibited a significant preference for images with pretarsal rolls compared to older groups (P < .001), and females displayed a greater inclination toward a medium ratio of pretarsal roll to palpebral fissure height than males did (0.5:1 P = .003, 0.618:1 P < .001). Conclusions: This study validates the optimal characteristics of pretarsal rolls, which provides insight into pretarsal roll aesthetics and holds significant implications for surgical planning and effect assessment in future periocular procedures involving pretarsal rolls. Level of Evidence: 3: