ArticleLiterature Review

Sleep Wrinkles: Facial Aging and Facial Distortion During Sleep

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Abstract

Wrinkles are just one indicator of facial aging, but an indicator that is of prime importance in our world of facial aesthetics. Wrinkles occur where fault lines develop in aging skin. Those fault lines may be due to skin distortion resulting from facial expression or may be due to skin distortion from mechanical compression during sleep. Expression wrinkles and sleep wrinkles differ in etiology, location, and anatomical pattern. Compression, shear, and stress forces act on the face in lateral or prone sleep positions. We review the literature relating to the development of wrinkles and the biomechanical changes that occur in response to intrinsic and extrinsic influences. We explore the possibility that compression during sleep not only results in wrinkles but may also contribute to facial skin expansion.

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... Exhibit 1: Pierard Classification of Wrinkles [26]  Atrophic wrinkles develop in exposed and nonexposed skin, disappear with skin traction, change in orientation with body posture, and are due to atrophy of the extracellular matrix.  Elastotic wrinkles develop in sun exposed skin, exhibit solar elastosis, become progressively permanent, and do not disappear with perpendicular traction. ...
... Expression wrinkles and sleep wrinkles differ in etiology, location, and anatomical pattern. Compression, shear, and stress forces act on the face in lateral or prone sleep positions ( Figure 6) [26]. Diet and Nutrition: Rhytides, sagging of skin, and loss of elasticity are all related to changes in the collagen and elastic fibers of the skin, which are themselves impacted by diet. ...
... External forces (including compression, tension, and shear) act on facial tissue in lateral or prone sleep positions[26]. During side or stomach sleeping, facial tissue is subject to shear, compression, and tensile mechanical forces. ...
Article
As the most voluminous organ of the body that is exposed to the outer environment, the skin suffers from both intrinsic and extrinsic aging factors. Skin aging is characterized by features such as wrinkling, loss of elasticity, laxity, and rough-textured appearance. This aging process is accompanied with phenotypic changes in cutaneous cells as well as structural and functional changes in extracellular matrix components such as collagens and elastin. With intrinsic aging, structural changes occur in the skin as a natural consequence of the biological changes over time and produce a certain number of histological, physiological, and biochemical modifications. Intrinsic aging is determined genetically (influence of gender and ethnic group), variable in function of skin site, and also influenced by hormonal changes. Visually it is characterized by fine wrinkles. By comparison, “photoaging” is the term used to describe the changes occurring in the skin, resulting from repetitive exposure to sunlight. The histological, physiological, and biochemical changes in the different layers of the skin are much more drastic. From a mechanical point of view, human skin appears as a layered composite containing the stiff thin cover layer presented by the stratum corneum, below which are the more compliant layers of viable epidermis and dermis and further below the much more compliant adjacent layer of subcutaneous white adipose tissue.
... Usually skin wrinkles emerge and increase along with the aging processes, and extensive skin wrinkles exist in elder mammals, especially for facial wrinkles. According to histological differences and possible causes, skin wrinkles were typically classified into five categories: atrophic wrinkles, elastotic wrinkles, expressional wrinkles, gravitational wrinkles and sleep wrinkles, respectively [1][2][3][4]. It has been reported that many intrinsic and extrinsic factors contributed to skin wrinkle development and formation [4,5], which included slower epidermal turnover, increased skin fragility, decreased nutrients transfer between skin layers, loss of sebaceous glands and reduced oil production in skin, loss of fat support and less padding of fat tissue under skin, ultraviolet oxidative damage, harsh weather and pollution, and repeated skin movement. ...
... According to histological differences and possible causes, skin wrinkles were typically classified into five categories: atrophic wrinkles, elastotic wrinkles, expressional wrinkles, gravitational wrinkles and sleep wrinkles, respectively [1][2][3][4]. It has been reported that many intrinsic and extrinsic factors contributed to skin wrinkle development and formation [4,5], which included slower epidermal turnover, increased skin fragility, decreased nutrients transfer between skin layers, loss of sebaceous glands and reduced oil production in skin, loss of fat support and less padding of fat tissue under skin, ultraviolet oxidative damage, harsh weather and pollution, and repeated skin movement. ...
Article
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Wrinkles are uneven concave-convex folds, ridges or creases in skin. Facial wrinkles appear in head, typically increasing along with aging. However in several Chinese indigenous pigs, such as Erhualian pigs, rich facial wrinkles have been generated during the growth stages as one of their breed characteristics. To investigate the genetic basis underlying the development of swine facial wrinkles, we estimated the folding extent of facial wrinkles in a herd of Erhualian pigs (n=332), and then conducted genome-wide association studies and multi-trait meta-analysis for facial wrinkles using 60K porcine chips. We found that facial wrinkles had high heritability estimates of ~0.7 in Erhualian pigs. Notably, only one genome-wide significant QTL was detected at 34.8 Mb on porcine chromosome 7. The most significant SNP rs80983858 located at the 3255-bp downstream of candidate gene GRM4, and the G allele was of benefit to increase facial wrinkles. Evolutionary and selection analyses suggested that the haplotypes containing G allele were under artificial selection, which was consistent with local animal sacrificial custom praying for longevity. Our findings made important clues for further deciphering the molecular mechanism of swine facial wrinkles formation, and shed light on the research of skin wrinkle development in human or other mammals.
... • Gravitational wrinkles due to skin sagging in response to gravitational forces and inelasticity. Exhibit 1: Pierard classification of wrinkles [26]. ...
... Expression wrinkles and sleep wrinkles differ in etiology, location, and anatomical pattern. Compression, shear, and stress forces act on the face in lateral or prone sleep positions ( Figure 6) [27]. ...
... Expression wrinkles and sleep wrinkles differ in etiology, location, and anatomical pattern. Compression, shear, and stress forces act on the face in lateral or prone sleep positions ( Figure 6) [26]. ...
Article
Full-text available
As the most voluminous organ of the body that is exposed to the outer environment, the skin suffers from both intrinsic and extrinsic aging factors. Skin aging is characterized by features such as wrinkling, loss of elasticity, laxity, and rough-textured appearance. This aging process is accompanied with phenotypic changes in cutaneous cells as well as structural and functional changes in extracellular matrix components such as collagens and elastin. With intrinsic aging, structural changes occur in the skin as a natural consequence of the biological changes over time and produce a certain number of histological, physiological, and biochemical modifications. Intrinsic aging is determined genetically (influence of gender and ethnic group), variable in function of skin site, and also influenced by hormonal changes. Visually it is characterized by fine wrinkles. By comparison, “photoaging” is the term used to describe the changes occurring in the skin, resulting from repetitive exposure to sunlight. The histological, physiological, and biochemical changes in the different layers of the skin are much more drastic. From a mechanical point of view, human skin appears as a layered composite containing the stiff thin cover layer presented by the stratum corneum, below which are the more compliant layers of viable epidermis and dermis and further below the much more compliant adjacent layer of subcutaneous white adipose tissue. Upon exposure to a strain, such a multi-layer system demonstrates structural instabilities in its stiffer layers, which in its simplest form is the wrinkling. These instabilities appear hierarchically when the mechanical strain in the skin exceeds some critical values. Their appearance is mainly dependent on the mismatch in mechanical properties between adjacent skin layers or between the skin and subcutaneous white adipose tissue, on the adhesive strength and thickness ratios between the layers, on their bending and tensile stiffness as well as on the value of the stress existing in single layers. Gradual reduction of elastic fibers in aging significantly reduces the skin’s ability to bend, prompting an up to 4-fold reduction of its stability against wrinkling, thereby explaining the role of these fibers in skin aging. Anti-aging medicine is practiced by physicians, scientists, and researchers dedicated to the belief that the process of physical aging in humans can be slowed, stopped, or even reversed through existing medical and scientific interventions. This specialty of medicine is based on the very early detection and prevention of age-related diseases. Physicians practicing anti-aging medicine seek to enhance the quality of life as well as its length, limiting the period of illness and disability toward the end of one’s life. Anti-aging medicine encompasses lifestyle changes (diet and exercise); hormone replacement therapies, as needed, determined by a physician through blood testing (DHEA, melatonin, thyroid, human growth hormone, estrogen, testosterone); antioxidants and vitamin supplements; and testing protocols that can measure not only hormone levels and blood chemistry but every metabolic factor right down to the cellular level.
... Replacement of dWAT volume with fibrosis leads to production of mechanically heterogeneous skin structures and to the loss of the effective skin volume. [8]. During side or stomach sleeping, facial tissue is subject to shear, compression, and tensile mechanical forces. ...
Book
Skin aging is a complex biological process influenced by a combination of endogenous or intrinsic and exogenous or extrinsic factors. Because of the fact that skin health and beauty is considered one of the principal factors representing overall “well-being” and the perception of “health” in humans, several anti-aging strategies have been developed during the last years. In contrast to thin and atrophic, finely wrinkled and dry intrinsically aged skin, premature photoaged skin typically shows a thickened epidermis, mottled discoloration, deep wrinkles, laxity, dullness and roughness. Gradual loss of skin elasticity leads to the phenomenon of sagging. Slowing of the epidermal turnover rate and cell cycle lengthening coincides with a slower wound healing and less effective desquamation in older adults. This fact is important when esthetic procedures are scheduled. On the other side, many of these features are targets to product application or procedures to accelerate the cell cycle, in the belief that a faster turnover rate will yield improvement in skin appearance and will speed wound healing. A marked loss of fibrillin-positive structures as well as a reduced content of collagen type VII (Col-7, may contribute to wrinkles by weakening the bond between dermis and epidermis of extrinsically age skin. Sun-exposed aged skin is characterized by the solar elastosis. The sparse distribution and decrease in collagen content in photoaged skin can be due to increased collagen degradation by various matrix metalloproteinases, serine, and other proteases irrespective of the same collagen production. The overall collagen content per unit area of the skin surface is known to decline approximately 1%/year. Glycosaminoglycans (GAGs are among the primary dermal skin matrix constituents assisting in binding water. In photo-aged skin, GAGs may be associated with abnormal elastotic material and thus be unable to function effectively. The total hyaluronic acid (HA level in the dermis of skin that age intrinsically remains stable; however, epidermal HA diminishes markedly. Decreased estrogen levels may play a role in skin aging in women and compounds stimulating estrogen receptors could potentially counteract some of the visible signs of aging. As people live longer, women spend a larger portion of their lives in a post-menopausal state, with a deficiency of estrogen as compared to their younger selves. Changes in diet and increasing exercise, together with a regimen of antioxidants, nutritional supplements, and growth factors, can alter how the genes express themselves. Both factors can greatly enhance the healing capability of the skin and can improve the results of cosmetic surgeries.
... (v) Ercan et al. [3] proposed that there is a correlation between the level of facial asymmetry and facial side. Anson et al. [31] explored that facial wrinkles are developed by the compression during sleep which also contribute to facial skin expansion. The experimental results presented in our study support these notions, by showing that bilateral facial asymmetry based asymmetric right face images can be used for age estimation of a given face image with reduced MAE compared to its counterparts i.e., the original and left asymmetric face images. ...
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Aging affects left and right half face differently owing to numerous factors such as sleeping habits, exposure to sun light, and weaker face muscles of one side of face. In computer vision, age of a given face image is estimated using features that are correlated with age, such as moles, scars, and wrinkles. In this study we report the asymmetric aging of the left and right sides of face images and its impact on accurate age estimation. Left symmetric faces were perceived as younger while right symmetric faces were perceived as older when presented to the state-of-the-art age estimator. These findings show that facial aging is an asymmetric process which plays role in accurate facial age estimation. Experimental results on two large datasets verify the significance of using asymmetric right face image to estimate the age of a query face image more accurately compared to the corresponding original or left asymmetric face image.
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Background Altmetrics (alternative metrics) has become one of the most commonly used metrics to track the impact of research articles across electronic and social media platforms. Objective The goal of this study is to identify whether the Altmetric Attention Score (AAS) is a good proxy for citation counts and whether it can be used as an accurate measure to complement the current gold standard. Methods We conducted a citation analysis of all articles published in six plastic surgery journals during the 2016 calendar year. Citation counts and AAS were abstracted and analyzed. Results We identified a total of 1,420 articles. The mean AAS was 11 while the median AAS was 1. The journal with the highest mean AAS was Aesthetic Surgery Journal (31), followed by Plastic and Reconstructive Surgery (19). A weak positive correlation was identified (r=0.33, p<0.0001) between AAS and citations. Articles in the top 1% in terms of citation counts showed strong positive correlation between AAS and citation counts (r=0.64, p=0.01). On the contrary, articles in the top 1% of AAS had no significant correlation with citation counts (r=-0.31, p=0.29). Conclusion Overall correlation between citations and AAS was weak, and therefor AAS may not be an accurate early predictor of future citations. The two metrics seem to measure different aspects of the impact of scholarly work and should be used in tandem for determining the reach of a scientific article.
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The ongoing positive aging trend has resulted in many research studies being conducted to determine the characteristics of aging and what steps we can take to prevent the extrinsic signs of aging. Much of this attention has been focused on the prevention and treatment of facial wrinkles. To treat or prevent facial wrinkles correctly, their causative action first needs to be determined. published very compelling evidence that the development of wrinkles is complex and is caused by more factors than just the combination of poor lifestyle choices.
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This paper presents a computational model for studying the mechanical properties of skin with aging. In particular, attention is given to the folding capacity of skin, which may be manifested as wrinkles. The simulation provides visual results demonstrating the form and density of folds under the various conditions. This can help in the consideration of proper measures for a cosmetic product for the skin.
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Background: Light and electron microscopy have not identified a distinct anatomical structure associated with either skin wrinkles or creases, and a histological difference between wrinkled and adjacent skin has not been identified. Objectives: The authors investigate whether facial wrinkles are related to underlying lymphatic vessels and perilymphatic fat. Methods: Lymphatic vessels with a specialized tube of perilymphatic fat were identified beneath palmar creases. Sections of skin, adipose tissue, and muscle were harvested from each of 13 cadavers. Three sites were investigated: the transverse forehead crease, lateral orbicularis oculi wrinkle (crow's feet), and the nasojugal crease. The tissue was paraffin embedded and processed. Two-step indirect immunohistochemistry was performed, and images were examined using laser confocal microscopy. Measurements were taken with software. Results: Every wrinkle examined was found above and within ±1 mm of a major lymphatic vessel and its surrounding tube of adipose tissue. The results satisfied our null hypothesis and were statistically significant. Lymphatic vessels were identified by positive immunofluorescence as well as histological criteria. These findings have been further validated by fluorochrome tracer studies. Conclusions: An anatomical basis for wrinkles was identified among the specimens studied. Lymphatic vessels, along with the surrounding distinct perilymphatic fat, traveled directly beneath wrinkles and creases. Lymphatic dysregulation leads to inflammation, scarring, and fibrosis, but inadvertent injection of these vessels can be avoided with anatomical knowledge.
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To determine whether there is an association between sleep position and the appearance of facial wrinkles and facial descent. One hundred women were questioned about their sleep position preference. An independent expert observer evaluated frontal images with digital laterality randomization to identify the side with more wrinkles and more ptosis. Forty-one right-sided sleepers and 23 left-sided sleepers were identified. There was statistical independence between sleep side and side with more wrinkles and between sleep side and side with more facial ptosis according to the Pearson chi-square test. Sleep side preference was not significantly correlated with the appearance of wrinkles or facial descent.
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The Dermal-Epidermal Junction (DEJ) is characterized by undulations whose apices are called papillae. With aging, epidermis becomes thinner, together with a flattening of the DEJ, leading to a decreased density of papillae. The causes of these modifications are likely as multiple as uncertain. The present paper deals with in vivo morphometric characterization of the DEJ and its changes following a skin surface deformation. Living epidermis of human adults was examined by means of in vivo Reflectance Confocal Microscopy. Distances between skin surface and papillae apex and pegs of the DEJ were, respectively, recorded in both relaxed and stretched skin situation. The number of papillae present within a single image (field of view, 500 × 500 μm) was also measured. Skin extension has no effect upon the distance between skin surface and the apex of papillae. In contrast, the distance between skin surface and the pegs of papillae decreases. On the other hand, skin extension leads to a significant decrease in the number of papillae within a single image. Epidermal atrophy and structural changes observed in the DEJ with aging may be, by some extent, related to daily and repetitive skin deformations all along the life span.
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Background: External volume expansion by suction has been proposed to improve the survival of fat grafting by preparing the recipient site. In previous experimental work, external volume expansion demonstrated the capacity to stimulate cell proliferation, vessel remodeling, and adipogenesis. This study investigated possible mechanisms underlying these observed changes. Methods: A miniaturized external volume expansion device was applied to the dorsum of mice for 2 hours. Hypoxia during stimulation was assessed with pimonidazole hydrochloride, and tissue perfusion was measured for up to 2 days using hyperspectral imaging. Treated tissues were evaluated by microscopy for edema, inflammation, and the effects on cell proliferation and vessel remodeling. Results: External volume expansion-treated tissues were grossly expanded with 2 hours of stimulation, developing a macroscopic swelling that regressed slowly over the course of hours following stimulus cessation. This gross swelling was reflective of histologic signs of intense edema, persistent for at least 1 hour after external volume expansion. Tissues were hypoxic during stimulation, and hyperspectral imaging demonstrated decreased tissue content of both oxygenated and deoxygenated hemoglobin in the first hour after external volume expansion release. The onset of inflammation was already apparent by the end of stimulation and remained elevated through 2 days after external volume expansion. At this time point, epidermal and dermal cell proliferation and vascular density were significantly increased. Conclusion: External volume expansion sets in motion various mechanisms, including mechanical stimulation, edema, ischemia, and inflammation, that over distinct time periods maintain an environment conducive to cell proliferation and angiogenesis, which can be elicited even by a single 2-hour external volume expansion cycle.
Article
This article discusses skin expansion without considering cellular growth of the skin. An in vivo analysis was carried out that involved expansion at three different sites on one patient, allowing for the observation of the relaxation process. Those measurements were used to characterize the human skin of the thorax during the surgical process of skin expansion. A comparison between the in vivo results and the numerical finite elements model of the expansion was used to identify the material elastic parameters of the skin of the thorax of that patient. Delfino's constitutive equation was chosen to model the in vivo results. The skin is considered to be an isotropic, homogeneous, hyperelastic, and incompressible membrane. When the skin is extended, such as with expanders, the collagen fibers are also extended and cause stiffening in the skin, which results in increasing resistance to expansion or further stretching. We observed this phenomenon as an increase in the parameters as subsequent expansions continued. The number and shape of the skin expanders used in expansions were also studied, both mathematically and experimentally. The choice of the site where the expansion should be performed is discussed to enlighten problems that can lead to frustrated skin expansions. These results are very encouraging and provide insight into our understanding of the behavior of stretched skin by expansion. To our knowledge, this study has provided results that considerably improve our understanding of the behavior of human skin under expansion.
Article
Background: The skin possesses unique biochemical properties that allow it to protect and conform to the body that it covers. Elements constituting the dermis-collagen and elastin-primarily afford these properties. Objectives: To define these properties and explore their relevance with regard to aging skin and dermatologic surgery. Materials and methods: In the first part of this review, the determinants of mechanical properties of the skin will be outlined, through an extensive review of the literature. General physical properties that explain the behavior of skin will be defined, and diseases that manifest the extremes of those properties will be discussed. In the second half of this discussion, the surgical implications of skin biomechanics will be reviewed. Results: Emphasis will be placed on understanding how dermatologic surgeons may optimally use skin properties to produce the best cosmetic and functional outcomes possible. Conclusion: Understanding of the biomechanical properties of skin is paramount to obtain the best cosmetic outcomes in dermatologic surgery.
Article
Background: The effects of hyaluronic acid (HA) injection on tissue collagen anabolism are suggested to be related to the induction of mechanical stress, causing biochemical changes in skin physiology. Objectives: To ascertain the association between dermal mechanics modulated by a hyaluronic acid-based filler effect and metabolism. Methods: Sixty females were randomised to receive a 0.5mL injection of HA gel or isotonic sodium chloride (control) in the arm. Skin biopsies were taken at baseline and after 1, 3 and 6 months. Protein and gene expression of procollagen, matrix metalloproteinases (MMP) and MMP tissue inhibitors (TIMP1) were measured blind by ELISA and qPCR, respectively. Injected volumes were measured by high-frequency ultrasound and radiofrequency analysis. Skin layer effects of injections were analysed by finite element digital modelling. Results: One month after injection, the filler induced an increase in procollagen (p=0.0016) and TIMP-1 (p=0.0485) levels and relative gene expression of procollagen III and I isoforms compared with the controls. After 3 months, procollagen levels remained greater than in the controls (p=0.0005), whereas procollagen expression and TIMP-1 and MMP content were no longer different. Forty-three percent of the injected filler volume was found at 1 month, 26% after 3 months and 20% after 6 months. Limitations: The ultrasound imaging technique limited the scope of the investigation and precluded an evaluation of the action of the filler at the hypodermic level. Conclusions: Integrating both mechanical and biological aspects, our results suggest that mechanical stress generated by cross-linked HA plays a role in dermal cell biochemical response.
Article
Skin mechanical properties are globally well described. The aim of this paper is to evaluate, by means of a numerical model, the influence of Stratum Corneum (SC) on skin folding resulting from an in-plane compression. A computational skin model was developed where skin is divided into three layers (SC, epidermis and upper dermis, and deep dermis) of different thicknesses and elastic moduli. Skin surface deformation, consecutive to the application of a given surface compression, was computed by minimizing the mechanical energy of the multi-layered tissue. Influence of SC thickness and elastic modulus on skin buckling is presented. Varying both SC thickness and elastic modulus has a marked influence on both wavelength and amplitude of the skin's surface folds. These two parameters display a logarithmic variation versus SC elastic modulus. Although representing about one hundredth of the total skin thickness, SC has a marked influence on the skin mechanical properties.
Article
Although there have been many studies investigating facial movements using three-dimensional (3D) quantitative analysis, the possible relationship between the levels of wrinkles and the movement distance of facial skin has previously not been reported. Forty-four healthy Japanese women (from 20 to 50 years, average = 47.7 ± 3.6 years) were recruited for this study with written informed consent. Infrared reflective marks were attached on their forehead skin, and then moving images of facial skin motions (raising the eyebrows) were captured using two infrared cameras under infrared ray irradiation. Calibration for the absolute value of distance was established using an exact one-point 3-m cube having infrared reflective marks at each apex. The two pupils and the top of the nose were setup as fixed standard points. 3D motion analysis was then carried out using Move-tr/3D™ software to determine the absolute distances of skin surface movements. Levels of wrinkles were determined using a 3D roughness analyzer (PRIMOS™) directly at rest and when raising the eyebrows. The wrinkle levels at rest showed a relatively high and significant correlation with wrinkles when strongly raising the eyebrows. Although the wrinkle levels at rest showed no correlation with the movement distance, the wrinkle levels when raising the eyebrows showed a significant correlation with the movement distance. The ratio of change based on the distance between the marks at rest and when raising the eyebrows showed similar correlation results. These results suggest that both the levels of skin deformation caused by movements and the wrinkles at rest are important factors that determine the wrinkle level when raising the eyebrows. However, the level of skin deformation is not important for wrinkle levels at rest, which indicates that other factors such as skin elasticity are also important for the formation of wrinkles.
Article
The goal of the described study was complex assessment of age-specific morphofunctional features of skin of different anatomic localization using optical coherence tomography (OCT). Forty-three healthy volunteers aging from 4 to 74 years were enrolled in the study. Optical and functional skin parameters were studied in 18 areas of the human body. All the studied areas were classified as open and closed, depending on external impact. Structural parameters of skin were determined by means of the OCT device equipped with a removable, flexible probe with microscanner (registration certificate no. 022a2035/2213-05) designed and fabricated at the IAP RAS (Nizhny Novgorod, Russia) with longitudinal and transverse resolution of about 20 μm. Age-specific morphofunctional features of skin most evident in areas exposed to external action were found. Statistically significant difference in elasticity (−0.57, P = 0.00012) in areas closed to external action (further referred to as closed areas) and in useful signal depth, hydration and elasticity in areas exposed to external action (further referred to as open areas) was assessed for different age groups. Analysis of the dependence of parameters on age showed statistically significant correlations between age and thickness of cellular layers of the epidermis (−0.33, P = 0.035), pigmentation level (−0.22, P = 0.044) and elasticity in closed areas and highly significant correlations between age and hydration and elasticity in open areas. The current work is concerned with investigation of age-specific morpho-functional parameters of skin of different localizations.
Article
Wrinkles result from distinct structural changes occurring in specific parts of the dermis and subcutaneous tissue. There is a need for evidenced-based cosmetology identifying and quantifying the different aspects of wrinkling. Histology allows to detect specific changes associated with particular types of wrinkles. Four main types of wrinkles can thus be recognized, including the atrophic crinkling rhytids, the permanent elastotic creases, the dynamic expression lines, and the gravitational folds. Each type usually develops on specific skin regions exhibiting distinct microanatomical characteristics. Whereas skin microrelief, expression lines and skin folds appear clearly marked at the histological level, only little dermal changes are identified under other reducible or permanent wrinkles compared with the skin immediately adjacent to them. Distinguishing different types of wrinkles brings more precision to the clinical practice. This is of importance because the different types of wrinkles respond differently to cosmetic, dermatological and surgical treatments.
Article
Various skin parameters including skin visco-elasticity and hydration level affect the formation of wrinkles. The aim of this study was to investigate the comprehensive and objective relationship between age, skin visco-elasticity, hydration level, and the occurrence of wrinkles using bioengineering equipments for the first time. A total number of 97 healthy women were included in this study. Age, Fitzpatrick skin type, skin mechanical parameters obtained with Cutometer®(R0~R9), hydration level measured with Corneometer®, as well as wrinkle parameters (SEsm, SEr, SEsc, and SEw) assessed with Visioscan®, were analyzed with the Pearson's correlation test. The skin fluidity (R6) increased while the elastic recovery ratio (R7) decreased with the age. The wrinkle parameter (SEw) also increased with the age. The higher skin hysteresis values (R4 and R9) coincided with the higher SEw values. Skin hydration significantly lowered the hysteresis (R9), the wrinkles (SEw), and the depth of wrinkle furrows (R3mr). The elderly have less elastic skin and more wrinkles. Skin hysteresis most closely related with the degree of wrinkles. Drier skin showed more wrinkles and deeper furrows, with wider intervals. On the basis of these objective findings, we propose several skin parameters associated with wrinkles, and hypothesize the mechanism of wrinkle generation.
Article
Objectives: To define normal values for total sleep time, sleep latency, sleep efficiency, sleep stages and sleeping positions in women and to investigate how sleep is affected by age, obesity, sleep apnea, smoking, alcohol dependency and hypertension. Methods: In a population-based study, 400 Swedish women aged 20-70 years with over-sampling of snorers were investigated using overnight in-home polysomnography. All results are weighted. Results: The mean normal total sleep time was 392 min, sleep latency 22 min and sleep efficiency 82%. Women spent 31 min in sleep stage 1, 244 min in stage 2, 41 min in stage 3/4 and 76 min in rapid eye movement (REM) sleep. They spent 41% of their sleep time in the supine position, 50% in the lateral position and 9% in the prone position. Multivariate analyses revealed that sleep efficiency was lower in older women and in women with hypertension. Sleep latency was short in women with severe sleep apnea and long in smokers, alcohol-dependent and hypertensive women. Sleep stage 3/4 was inversely related to age and body mass index. Less REM sleep occurred in alcohol-dependent women. Women younger than 45 years old slept a mean of 42% in the lateral position while women of 45 years and older slept 57% in the lateral position (p<0.001). Conclusions: In this population-based study of women, we present normal values for sleep stages and sleeping position. We conclude that age, body mass index, obstructive sleep apnea, smoking, alcohol and hypertension reduce sleep quality. With age, women spend more time sleeping in the lateral position.
Article
Does the morphology of wrinkles alter gradually with aging or suddenly at a certain age? On the basis of the theoretic wrinkle simulation of ideal skin, we have suggested that the wrinkle morphology suddenly changes from stratum corneum wrinkling to epidermis wrinkling; the former induces shallow fine furrows, and the latter induces deep prominent wrinkles. To examine the existence of drastic change in wrinkling morphology, we developed a new measurement system for facial skin wrinkling test. The mechanical compression test of facial skin was carried out for 102 Japanese women aged 25-56 years. The test was performed on the right temple area skin, and the area of wrinkles induced by the compression was measured using a digital video camera. The rate of increase in wrinkle area during compression was defined as the skin wrinkling rate, and it was calculated for all subjects automatically by image processing. The test results showed that the skin wrinkling rate underwent a step increase at the age 33, which means that the wrinkling morphologies of young and old skins are completely different, and so it changes suddenly in the early 30s. A new skin measurement system was developed to validate our theory of wrinkle formation mechanism with aging. The results demonstrated the wrinkling morphology changes suddenly at early 30s.
Article
Background: The possible relationship between the direction of wrinkles and the movement of facial skin has not previously been reported. Therefore, we characterized that relationship using particle image velocimetry (PIV) analysis. Method: Twenty-one healthy Japanese women aged in their 20s (n = 7) or 50s (n = 14) were recruited for this study. Moving images of facial skin motions (closing the eyes tightly, raising the eyebrows) were captured using a single infrared camera under infrared ray irradiation of the skin. PIV analysis was then carried out using Flow-Vec32 software to determine the velocity and the direction of skin surface movements. Results: All skin movements caused by those motions were finished within 0.20 s. During the motion of closing the eyes, skin at the eye periphery did not move in a superior-inferior direction, but did move toward the center of the eye (pupilla) with complex flows. There was no significant difference between either age group of subjects. During the motion of raising the eyebrows, the forehead skin moved upwards (direction to parietal) with relatively uniform flows. The velocity of movement at the top was lower than at the bottom, and that difference is likely to cause a deformation on the skin surface. A significant difference between the two age groups in the velocity was observed. Conclusion: The results show that the deformation of older skin on the forehead is greater than that in younger skin. The PIV analysis method is a useful tool to investigate some aspects of the relationship between facial skin movements and wrinkle formation.
Article
To study the changes in skin microrelief and periocular wrinkles during the aging process. Replicas of the crow's feet area of volunteers were recorded in 1987 and 2008 and observed comparatively. Characteristic features were quantified by image analysis. Observation shows that some microrelief features disappear and even merge with wrinkles that become more marked. Some primary lines also tend to merge to form thin new wrinkles. Quantitative data support these observations: the size of small and medium objects of skin relief decreases with age while large objects are becoming larger. Over 21 years, in the group studied, the total area of the detected objects remains quite constant. Only the distribution between small and large detected objects (microrelief features and wrinkles, respectively) is modified.
Article
The mechanical aspects of wrinkle formation were studied in the dorsal skin of hairless mice. Wrinkles were induced by irradiating with ultraviolet (UV) B for 10 weeks, while observing skin deformation during wrinkle formation. Changes in skin dimensions were also observed during the specimen excision process. Wrinkle depth and interval were measured before and after removal of the cutaneous muscle layer. Local deformation of wrinkled skin during uniaxial stretch was also measured. Changes in curvature of skin specimens upon muscle layer removal were then observed to determine the force balance in skin layers. The skin showed spontaneous contraction in response to UV irradiation. Wrinkled skin showed a marked decrease in the wrinkle depth and a slight increase in wrinkle interval following muscle layer removal, a peculiar mechanical response that cannot be explained by homogeneous deformation of the skin. This response was due to compressive deformations of dermal tissue caused by the muscle layer and concentrated at valleys of the wrinkles. Curvature measurements indicated that the muscle layer compressed the dermal tissue predominantly in the craniocaudal direction. Morphological observations showed that the wrinkles coincided with rows of pores and sulci cutis, where the structural stiffness of the horny layer was relatively low. The horny layer showed significant thickening. Taken together, we propose the following hypothetical mechanisms of wrinkle formation during UV irradiation: spontaneous contraction of the dermis while maintaining or increasing the epidermal area induces buckling of the epidermis into the dermis at mechanically weak lines, namely, the rows of pores and sulci cutis, and buckling may be amplified by the axial compression of the dermis by the muscle layer.
Article
While cumulative lifetime sun exposure is well recognized as having an important role in the progression of facial wrinkling, the role of facial expression has largely been overlooked, in part due to the lack of comprehensive longitudinal data on the change in both expression lines and persistent wrinkles with age. To track the detailed pattern of facial wrinkling in the same group of people over several years and to verify that expression lines evolve into persistent wrinkles. In addition, to identify factors predictive of a faster or slower rate of wrinkling. Standardized images were captured at baseline and at 8 years of 122 women (ages 10-72 years, skin types I-VI) with and without a smiling expression. The wrinkle pattern with expression at baseline was compared with the pattern without expression at 8 years. Severity of facial wrinkling was quantified using computer-based image analysis. Skin colour, hydration, sebum and pH were measured at baseline. A structured questionnaire captured demographic and lifestyle data at baseline and at 8 years. Each subject's unique pattern of persistent facial wrinkling observed without expression at year 8 was predicted by the pattern of lines observed with a smiling expression at baseline. Having a drier, more alkaline stratum corneum, a lighter complexion, being middle-aged (40s) or becoming menopausal were associated with faster persistent wrinkling. Repeated skin flexure during facial expression causes persistent wrinkles. The pattern of expression lines predicts the pattern of future persistent wrinkles. Certain intrinsic and extrinsic factors are not causative, but influence the rate, of facial wrinkling.
Article
Learning Objectives: The reader is presumed to have a basic understanding of facial anatomy and facial rejuvenation procedures. After reading this article, the reader should also be able to: Identify the essential anatomy of the face as it relates to facelift surgery.Describe the common types of facelift procedures, including their strengths and weaknesses.Apply appropriate preoperative and postoperative management for facelift patients.Describe common adjunctive procedures. Physicians may earn 1.0 AMA PRA Category 1 Credit™ by successfully completing the examination based on material covered in this article. This activity should take one hour to complete. The examination begins on page 464. As a measure of the success of the education we hope you will receive from this article, we encourage you to log on to the Aesthetic Society website and take the preexamination before reading this article. Once you have completed the article, you may then take the examination again for CME credit. The Aesthetic Society will be able to compare your answers and use these data for future reference as we attempt to continually improve the CME articles we offer. ASAPS members can complete this CME examination online by logging on to the ASAPS members–only website (http://www.surgery.org/members) and clicking on “Clinical Education” in the menu bar. Modern aesthetic surgery of the face began in the first part of the 20th century in the United States and Europe. Initial limited excisions gradually progressed to skin undermining and eventually to a variety of methods for contouring the subcutaneous facial tissue. This particular review focuses on the cheek and neck. While the lid–cheek junction, eyelids, and brow must also be considered to obtain a harmonious appearance, those elements are outside the scope of this article. Overall patient management, including patient selection, preoperative preparation, postoperative care, and potential complications are discussed.
Article
The mechanical properties of human skin are known to change with ageing, rendering skin less resistant to friction and shear forces, as well as more vulnerable to wounds. Until now, only few and contradictory results on the age-dependent friction properties of skin have been reported. This study has investigated in detail the influence of age on the friction of human skin against textiles. In vivo skin-friction measurements on a force plate were combined with skin analyses concerning elasticity, hydration, pH value and sebum content. Thirty-two young and 28 aged persons rubbed their volar forearm in a reciprocating motion against various textiles on the force plate, using defined normal loads and sliding velocities, representing clinically relevant contact conditions. Mean friction coefficients ranged from 0.30 +/- 0.04 (polytetrafluoroethylene) to 0.43 +/- 0.04 (cotton/polyester). No significant differences in the friction properties of skin were found between the age groups despite skin elasticity being significantly lower in the aged persons. Skin hydration was significantly higher in the elderly, whereas no significant differences were observed in either skin pH value or sebum content. Adhesion is usually assumed to be the dominant factor in skin friction, but our observations imply that deformation is also an important factor in the friction of aged skin. In the elderly, lower skin elasticity and skin turgor are associated with more pronounced skin tissue displacements and greater shear forces during frictional contact, emphasizing the importance of friction reduction in wound-prevention programmes.
Article
Aging of skin is accompanied by decrease of skin elasticity. Using the noninvasive suction device Cutometer, we evaluated the age and regional body differences of the viscoelastic properties of human skin. The objectives of this study were to evaluate the correlation between age and the biomechanical parameters and the regional skin variations. A total of 96 healthy women aged 20-75 years were included in this study. The biomechanical properties of the skin were measured by using the Cutometer. Measurements were made on the face, upper arm and back. The age of subjects showed significant positive correlation with R4 and R6, and negative correlation with R2, R5 and R7. The face showed bigger changes of elastic properties than the arm and the back. Especially, the R7 of face was most significantly decreased with aging. We could estimate the so-called 'skin age' by using a correlation equation for this parameter. The viscoelastic properties were significantly influenced by aging. Also, significant regional variations in the viscoelastic properties were observed. Skin elasticity measurement is useful for the quantitative evaluation of age-related changes.
Article
The zygomatic ligaments (McGregor's patch) anchor the skin of the cheek to the inferior border of the zygoma just posterior to the origin of the zygomaticus minor muscle. The mandibular ligaments tether the overlying skin to the anterior mandible. Both these ligaments are obstacles to surgical maneuvers intended to advance the overlying skin. They also restrain the facial skin against gravitational changes, and they delineate the anterior border of the "jowl" area. The platysma-auricular ligament is a thin fascial sheet that extends from the posterosuperior border of the platysma and that is intimately attached to the periauricular skin; it serves as a surgical guide to the posterosuperior border of the platysma. The anterior platysma-cutaneous ligaments are variable fascial condensations that anchor the SMAS and platysma to the dermis. They can cause anatomic disorientation with dissection of false planes into the dermis. These four ligaments are useful as anatomic landmarks during facial dissections. The tethering effects of the zygomatic and mandibular ligaments must be interrupted if a maximum upward movement of the facial skin is desired.
Article
The anatomy of linear wrinkles ("crow's feet' and temporal frown lines), fine criss-cross wrinkles of the face and wrinkling of the general body surface of elderly persons, was studied by light and scanning electron microscopy. No histological features distinguished the various wrinkles from surrounding skin. It was concluded that the wrinkle is a configuration change, like the grooves worn into an old glove, without specific structural alterations at the histological level. As regards pathogenesis, the common setting was found to be deterioration of the elastic tissue network. The skin becomes looser, excessive, and loses the ability to snap back to its original state after being deformed.
Article
Using recently designed, commercially available, non-invasive instruments, we measured the thickness and elasticity of the skin of the face and ventral forearm in 170 women, and evaluated the effects of age and exposure to sunlight. Skin thickness decreased with age in ventral forearm skin, which has limited exposure to sunlight, but increased significantly in the skin of the forehead, corners of the eyes, and cheeks, which are markedly exposed to sunlight. Skin elasticity (Ur/Uf) decreased with age on both the face and forearm. The ratio of viscosity element to elasticity element (Uv/Ue) increased with age at all sites. However, delayed distension (Uv), immediate retraction (Ur), final distension (Uf), and immediate distention (Ue), as individual elements, decreased on the face and increased on the forearm with age. This tendency was more marked after correction for skin thickness. These results suggested the specificity of skin thickness and elasticity in the facial skin. Analysis using a four-element model showed no changes in the elasticity coefficient of Maxwell element on the forearm, but an increase on the face. This indicates quantitative or qualitative changes in elastic fibres in facial skin. Thus, sunlight appears to have a considerable effect on the thickness and physical properties of facial skin.
Article
One of the most interesting medical conditions that now afflicts the baby boomer generation is photoaging. Clinical signs of photoaging of the skin include rhytids, lentigines, keratoses, telangiectasia, loss of translucency, loss of elasticity, and sallow color. A systematic classification of patient photoaging types has been developed by the author: type I, "no wrinkles"; type II, "wrinkles in motion"; type III, "wrinkles at rest"; and type IV, "only wrinkles." The intent is to organize the discussion of therapies for photodamaged skin to permit rational comparisons of therapies and clinical results.
Article
This is a tribute to Dr. Samuel J. Stegman who in 1987 described "Sleep Creases." His awareness of these lines has helped us understand the anatomy of the underlying superficial musculoaponeurotic system (SMAS). To expand upon the clinical description and the anatomical basis of sleep lines. A pillow or hand test is used to accentuate sleep lines. Their development is linked to the underlying attachments of the SMAS. There is a correlation between the location of the underlying SMAS or aberrant scar tissue and sleep lines. To effectively treat these lines, the sleeping position must be altered or subcision of the underlying SMAS attachments and skin resurfacing may improve the situation. We have confirmed Dr. Stegman's hallmark work on sleep wrinkles. They are accentuated by pillow contact and the underlying SMAS.
Article
We studied the relationship between sleep quality and bed surface firmness. Nine men were investigated, sleeping in their homes for at least 5 consecutive nights on a soft and a more firm mattress using a sensor pad placed under the mattress and a solid-state recording device. The subjective feeling of sleep quality did not always agree with the recorded sleep data. The difference was most marked when changing from the subject's own to one of the test mattresses. For the same subject the results were reproducible between nights provided there were no external disturbing factors. Four of the 9 subjects slept significantly better on the softer of the two mattresses and 2 on the hard mattress. The difference in sleep quality observed among the subjects tested makes it necessary to relate the results to the same person rather than considering a whole group as an entity. The adaptation period for a new sleep surface extended to many days.
Article
The body posture and gravitational forces govern in part the intrinsic skin tensile strength because they influence the orientation of the dermal fibre networks. Our objective was to assess changes in shear wave propagation in the skin according to the body posture and orientation of the gravitational forces. The study was performed in 30 middle-aged women with a normal body mass index. The Reviscometer was used to assess the mechanical wave propagation on the volar forearm in extension or flexion. Similar measurements were made on the supra-areolar region of the breast when the trunk was in the horizontal or vertical position. Four measurements were made in each of 4 directions at given angles with regard to the body axis. The device gave reproducible data. Shear wave propagation was influenced by the body posture. The intra-individual variability in shear wave velocity according to the directions of measurements increased when the tissues were in a relaxed position. Skin tensile anisotropy increased in a relaxed body posture. Shear wave propagation may be a convenient non-invasive tool to better identify the natural skin tension lines in the skin, thus refining the orientation of incision during cutaneous surgery.
Article
Noninvasive methods have allowed physicians to give an objective description of aged skin in terms of functional and esthetic properties. The relative influence of environment (mainly sun) on the true aging process can be assessed through the obtained data. It is also possible to measure the efficacy of topical preparations (cosmetics or drugs) designed for treating the various cutaneous aging marks.
Article
The influence of mechanical forces on skin has been examined since 1861 when Langer first reported the existence of lines of tension in cadaver skin. Internal tension in the dermis is not only passively transferred to the epidermis but also gives rise to active cell-extracellular matrix and cell-cell mechanical interactions that may be an important part of the homeostatic processes that are involved in normal skin metabolism. The purpose of this review is to analyse how internal and external mechanical loads are applied at the macromolecular and cellular levels in the epidermis and dermis. A review of the literature suggests that internal and external forces applied to dermal cells appear to be involved in mechanochemical transduction processes involving both cell-cell and cell-extra-cellular matrix (ECM) interactions. Internal forces present in dermis are the result of passive tension that is incorporated into the collagen fiber network during development. Active tension generated by fibroblasts involves specific interactions between cell membrane integrins and macromolecules found in the ECM, especially collagen fibrils. Forces appear to be transduced at the cell-ECM interface via re-arrangement of cytoskeletal elements, activation of stretch-induced changes in ion channels, cell contraction at adherens junctions, activation of cell membrane-associated secondary messenger pathways and through growth factor-like activities that influence cellular proliferation and protein synthesis. Internal and external mechanical loading appears to affect skin biology through mechanochemical transduction processes. Further studies are needed to understand how mechanical forces, energy storage and conversion of mechanical energy into changes in chemical potential of small and large macromolecules may occur and influence the metabolism of dermal cells.
Article
Plastic surgery must achieve the best cosmetic results, and it helps to consider certain skin lines. Aging and scars can cause the face to become lined, and we have noticed various facial lines among patients or their relations who have come to our outpatient clinic. These lines are sometimes single and there are sometimes 2-3 parallel lines generally in the same area of the face, such as the lateral orbital, temporal, frontal, and buccal regions. After detailed evaluation, we concluded that these oblique or horizontal wrinkles were caused by the position in which they slept. All of them slept prone, with their faces buried in the pillow, which over many years has caused wrinkling of the skin. We think therefore that sleeping position should be considered as an aetiological factor in the formation of wrinkles. The lines that should be taken into consideration during operation are Langer's lines, or relaxed skin tension lines, but not sleep lines. Here we describe the possible aetiology of sleep lines on the face.
Article
The age-related decrease of skin elasticity results in larger fatigue of adult skin than young skin after applying multiple stress at one and the same anatomic region. The aim of this study was to compare the informativeness of Cutometer standard R-parameters with new area parameters regarding the age-related changes in human skin fatigue. A total of 40 healthy volunteers aged 12-82 years were studied. Mechanical parameters of the skin were determined using a non-invasive suction skin elasticity meter (Cutometer). Measurements were made on the temporal region and volar forearm. Skin mechanical parameters analyzed by Win-Cutometer MPA software were R3, R4 and R9 (R-parameters), and F2 and F3 (area parameters). The adult skin was characterized by significantly higher values of R4, R9 and F2, and lower F3 compared with young skin. R3 was not significantly altered. There were not any sex-related differences. F2 correlated positively with parameters R3, R4 and R9, while F3 correlated negatively with R4. A positive correlation within the parameters R3, R4 and R9 was established at both anatomic regions. The non-invasive method applied can be useful for objective and quantitative investigation of age-related changes in skin fatigue and evaluation of the effects of cosmetic and anti-aging topical products. The mechanical parameters R4 and F3 are most indicative of human skin fatigue.
Article
Most studies of how the relief of the skin surface changes on ageing are based solely on topography, and a few have taken into account anisotropy parameters. However, the calculation of these parameters is often carried out manually and as the techniques of data acquisition have progressed rapidly, a certain degree of obsolescence has been reached. It is for this reason that we have undertaken a similar study but with more advanced equipment. The Dermatop system analyses the relief of Silflo negative prints of the skin surface. It is based on the projection of interference fringes and phase shift and provides surface parameters and not profiles. In addition, the Toposurf software enables image processing and the precise and automatic calculation of the topography parameters (roughness, developed surface area and peak-trough amplitude) and anisotropy (level of anisotropy and furrow density). These parameters were studied on the forearm and temple of 40 men and 40 women evenly distributed into two groups: the first including subjects aged 25-35 years and the second 50-65 years. Roughness of both sites increases with age, independent of sex, but to a lesser extent in women than in men. The developed surface area and the peak-trough amplitude increase significantly with age irrespective of the site and the sex. The level of anisotropy increases with age, in both men and women, on the forearm and the temple, the site more exposed to light being more affected. The density of the furrows decreases with age in both sexes and both sites but with a greater increase for the temple, which is more exposed to solar ageing. The study of these new parameters will allow objective evaluation of the action of topical dermatological and cosmetic treatment, and new techniques in plastic surgery (e.g. laser resurfacing), and will enable the accurate follow-up of certain pathologies.
Article
This paper explains how the shape of the spine can be evaluated from back surface measurements in a recumbent position, by using point distribution models (PDM) and typical shape variability of the spine in a lateral sleeping position. CT-scans of 12 volunteers were taken in this posture on a firm and a soft sleeping system to provide a training set for the PDM. Active shape models (ASM) were used to enhance the accuracy of the spinal reconstruction from measurements by limiting the shape of the spine to characteristic shapes from a biomechanical and/or clinical point of view. A comparison was made between calculated shapes, obtained from surface measurements, and those measured vertebral body centres (from CT-scans). An RMS accuracy of 2.6mm was obtained in 3D, and 1.8mm in frontal view, which was sufficient to compare spinal deformations of a subject on different sleeping systems.