Background Artificial Intelligence (A.I) and deep learning-based algorithms are increasingly being used in dermatology following the emergence of powerful smartphones with high-resolution cameras.Objectives To use an A.I-based algorithm, validated by dermatologists, to compare the evolution of the skin ageing process among Chinese and European women.Methods Selfie images were taken by 465 587 European and 79 016 Chinese women ranging from 18 to 85 and 18 to 69 years old, respectively, without facial skin diseases and who had access to a smartphone with a high-resolution camera (≥4 Megapixels). The selfies were analysed by facial skin diagnostic using a smartphone application to grade the severity of 9 facial signs (including wrinkles, sagging, vascular, pigmentation signs, pores).Results Wrinkles/texture, ptosis and sagging increased linearly with age in European women compared to lower scores and more gradual increase in the younger age-classes in Chinese women. In Chinese women, pigmentation signs increased regularly between 18 and 40 years, plateaued between 40 and 60 years, then increased in the over 60s compared to lower scores and a slower more regular increase with age in European women. Vascularization signs increased steadily with age in European women compared to no significant change in Chinese women. Conclusions Marked differences were observed in the skin ageing process between European and Chinese populations, both in the prevalence of each facial ageing sign and their kinetics. Automatic grading performed on selfies and analysed by A.I is a fast and confidential method for quantifying signs of facial ageing and identifying the main issues for each population and age-class, which is of practical interest, as it will allow the development of tailored prevention and therapeutic measures.

Background: Real-life validation is necessary to ensure our artificial intelligence (AI) skin diagnostic tool is inclusive across a diverse and representative US population of various ages, ancestries and skin phototypes.Objectives: To explore the relevance and accuracy of an automated, algorithm-based analysis of facial signs in representative women of different ancestries, ages and phototypes, living in the same country. Methods:In a cross-sectional study of selfie images of 1041 US women, algorithmbased analyses of seven facial signs were automatically graded by an AI-based algorithm and by 50 US dermatologists of various profiles (age, gender, ancestry, geographical location). For automated analysis and dermatologist assessment, the same referential skin atlas was used to standardize the grading scales. The average values and their variability were compared with respect to age, ancestry and phototype.Results: For five signs, the grading obtained by the automated system were strongly correlated with dermatologists' assessments (r ≥ 0.75); cheek skin pores were moderately correlated (r = 0.63) and pigmentation signs, especially for the darkest skin tones, were weakly correlated (r = 0.40) to the dermatologist assessments. Age and ancestry had no effect on the correlations. In many cases, the automated system performed better than the dermatologist-assessed clinical grading due to 0.3-0.5 grading unit differences among the dermatologist panel that were not related to any individual characteristic (e.g. gender, age, ancestry, location). The use of phototypes, as discontinuous categorical variables, is likely a limiting factor in the assessments of grading, whether obtained by automated analysis or clinical assessment of the images. Conclusions:The AI-based automatic procedure is accurate and clinically relevant for analysing facial signs in a diverse and inclusive population of US women, as confirmed by a diverse panel of dermatologists, although skin tone requires further improvement.

Background: Aging signs are much visible on the surface of the skin that presents different changes: cheeks start to sag, more and deeper wrinkles appear, and pigmentation spots increase. Face diagnostic to recommend products includes assessing cutaneous micro-relief or the micro-depressive network on the face. Furthermore, there is an increasing demand for clinical and instrumental methods to prove the efficacy of anti-aging treatments. As a result, very accurate and sensitive three-dimensional (3D) devices are developed and validated to measure and quantify aging skin and to catch fine anti-aging products acting on wrinkles and fine lines.Methods: AEVA-HE, a non-invasive 3D method based on fringe projection technology, is used to robustly characterize the skin micro-relief from a full-face acquisition and from multiple extracted zones of interest. In vitro and in vivo studies are conducted to assess the reproducibility of this system and its precision toward a standard fringe projection system, DermaTOP. Results:The AEVA-HE successfully measured micro-relief and wrinkles and demonstrated the reproducibility of measurements. AEVA-HE parameters were found highly correlated to DermaTOP. Conclusion:The present work illustrates the performance of the AEVA-HE device and its dedicated software kit as a precious tool for quantifying the major characteristics of wrinkles appearing with age and thus offers a high potential for assessing the effect of anti-wrinkling products.

Objective: To determine the aesthetical accordance between a given skin tone and the 11 possible colours of head hairs, covered by a marketed hair colouration product. Material and methods:The photographs of professional top models, representing several ancestries (non-Hispanic European and Euro-American, East Asian, Hispanic Euro-American, and African-American ancestries), were used to virtually modify skin tones (from light, medium to dark) and hair colour by an artificial intelligence (AI)-based algorithm. Hence, 117 modified photographs were then assessed by five local panels of about 60 women each (one in China, one in France and three in US). The same questionnaire was given to the panels, written in their own language, asking which and how both skin tones and hair colours fit preferentially (or not appreciated), asking in addition the reasons of their choices, using fixed wordings.Results: Answers from the five panels differed according to origin or cultural aspects, although some agreements were found among both non-Hispanic European and Euro-American groups. The Hispanic American panel in US globally much appreciated darker hair tones (HTs). Two panels (East Asian in China and African American in US) and part of non-Hispanic European panel in France declared appreciating all HTs, almost irrespective with the skin tone (light, medium and dark). This surprising result is very likely caused by gradings (in %) that differ by too low values, making the establishment of a decisive or significant assessment. By nature highly subjective (culturally and/or fashion driven), the assessments should be more viewed as trends, an unavoidable limit of the present virtual approach. The latter offers nevertheless a full respect of ethical rules as such objective could hardly be conducted in vivo: applying 10 or 11 hair colourations on the same individual is an unthinkable option. Conclusion:The virtual approach developed in the present study that mixes two major facial coloured phenotypes seems at the crossroad of both genetic backgrounds and the secular desire of a modified appearance. Nonetheless, this methodology could afford, at the individual level in total confidentiality, a great help to subjects exposed to some facial skin disorders or afflictions.

Objective:The objective of the study was to assess in vivo the validity of a new imaging device in quantifying the scarring process over time and to compare its data with the expertise of dermatologist and patients' self-appraisals. Materials and Methods:A total of 37 Korean women, aged 20-50 year, with closed scars of different types, were enrolled after a dermatological evaluation. All subjects applied daily a hydrating cream on their scars for 2 months. Images of scars at different times (Day 0, Day 28, and Day 56) were taken and further analyzed, yielding various parameters such as color, luminance, size, volume, and depth of each scar. A dermatologist visually graded, at each time point, the clinical aspect of the scar, and patients were asked to answer to some questions dealing with their self-examination of their scar. Results:The changes in some scar features that occurred during the application period were quantified and statistically differed from the D 0 baseline value. Scars became of reduced size, lighter (Increased luminance), less red, less deep, and less voluminous. Some of these parameters (volume, lightness, smoothness, texture regularity) were statistically different at D 28 whereas some others (area, depth, redness) showed significant changes at D 56 . Dermatologist expertise and patients' assessments were in high agreement. Conclusion:This methodological approach that uses a dedicated camera associated with image analysis, despite some inherent limits (size of the scar), appears as a valuable aid to surgeons in the management of scars, in the follow-up of a given procedure or treatment. Beyond scar management, this approach may be extended to other skin disorders such as acne.