scholarly journals The Superficial Musculoaponeurotic System of the Face: A Model Explored

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
M. Broughton ◽  
G. M. Fyfe

Regional differences in the integument of the body are explained, at least in part, by differences in fascial arrangements. In the face, where the skin is more mobile due to the action of the underlying facial muscles, fascial organisation is important for support and separation of muscle groups. This study used bequeathed cadaver material to investigate a current model of the SMAS proposed by Macchi et al., the original boundaries of which were explored and extended using both histology and gross dissection. As a clearly identifiable structure spanning the lateral and midface, the SMAS in the specimen supported the model proposed by Macchi et al. The three main findings that support the model were the layered morphological appearance of the SMAS, its progression from fibrous to aponeurotic in a lateral to medial direction, and the enveloping of the zygomaticus musculature. Extension beyond the proposed model into the temporal region was observed, but nasal and forehead regions showed no evidence of SMAS, while its presence in the cervical platysma region remained inconclusive. Fascial and soft tissue variability was considerable within facial regions of the examined specimen, helping to explain the debate around the SMAS in the literature.

Author(s):  
H-M Sun ◽  
T-L Lin

An adjustable parameter model for tracking manoeuvring targets is presented using a modified variable variance intensity technique. This model is based on the Singer model but with modifications to its fixed manoeuvre statistical characteristics. Meanwhile, a ‘current model’ concept is adapted to describe the statistical distribution of the target's acceleration. Since the variance intensity of the proposed model is calculated using a variable manoeuvring probability density function with adequate covariance, it exhibits a strong adaptive ability for tracking a manoeuvring target and a reduced steady estimation bias in tracking a non-manoeuvring target. Computer simulation results show that a Kalman estimator based on this model can track both manoeuvring and non-manoeuvring targets with greater accuracy than either the Singer model or the interacting multiple model method and is suitable for online processing.


2021 ◽  
pp. 293-348
Author(s):  
Daniel R. van Gijn ◽  
Jonathan Dunne

The face conveys our conscious and subconscious emotions and projects vulnerability in disfigurement. Functionally, the face encompasses the muscles that surround our eyes, nose and mouth, contributing to the sphincters and dilators that allow the fine motor control of our eyelids, nostrils and lips, respectively. The face forms the anterior part of the head medial to the ears and between the hairline superiorly and the chin inferiorly. It comprises everything that lies between what is visible anteriorly and laterally. The face consists of four recognisable tissue planes – skin, a subcutaneous layer of fibroadipose tissue (held responsible for some of the changes of the ageing face), the superficial muscular aponeurotic system and the parotidomasseteric fascia. The scalp forms the soft tissue envelope of the cranial vault. The triad it forms with the forehead anteriorly and the temporal regions laterally should be considered as a continuum rather than three separate entities.


Author(s):  
Kai Kaye ◽  
Felix Paprottka ◽  
Sonja Kaestner ◽  
Phillipp Gonser

AbstractPurse string sutures in superficial musculoaponeurotic system (SMAS) plication facelifts may cause technique-related problems, such as soft tissue deformities, dimpling, and bulkiness inside and between the independent sutures. Therefore, the authors have developed a new approach named the multiple rhomboid vector (MRV) suture. A total of 103 patients (89 female, 14 male patients; median age: 57 years) received a primary rhytidectomy with the MRV SMAS plication suture in our clinic (2015–2017). Intraoperative time to perform the suture per side was recorded. Postoperative complications and dimpling and bulkiness of subcutaneous tissues were judged by three independent surgeons from 1 (= none) to 4 (= extreme) after 1 week, 1, 3, 6, and 12 months. A standardized survey, the FACE-Q questionnaire, was performed to evaluate postoperative patient satisfaction. Mean time to perform the suture was 5:14 minutes per side (minimum: 3:20 minutes, maximum: 5:53 minutes; standard deviation: 0:51 minutes). During the follow-up period, four complications were detected (two cases of temporary neurapraxia of the marginal branch of the mandibular nerve {n = 2 [1.9%]} and two cases of retroauricular hematoma {n = 2 [1.9%]}). Postoperative dimpling or bulkiness of subcutaneous tissues was judged as absent. Overall patient satisfaction rate, after the surgery was performed, was measured as “very high.” The MRV suture offers a combined horizontal and vertical suspension approach, which effectively addresses the different vectors of age-related facial soft tissue descent with complication rates equal to other surgical lifting techniques. Apart from that, it may help reduce the possibility of contour irregularities, whereby it must be noted that a thorough preoperative assessment together with the patient and surgical planning is crucial to ensure realistic expectations of the surgical outcome.


The regional anatomy of human skin is discussed in terms of ( a ) the regional variation of the architectural pattern of the basal layer of the epidermis, ( b ) the regional variation in the distribution of hair follicles and eccrine sweat glands, and the regional variation in the distribution of melanocytes. ( a ) The architecture of the basal layer is regionally specific. The epidermis of the cheek is almost flat between the numerous hair follicles. Regions under tension have parallel ridges that end abruptly (neck, breast, abdomen); regions with a thick keratin or mucous layer have deep ridges with circular imprints of tall dermal papillae (sole, palm, knee, heel and oral mucosa). Elsewhere in the epidermis the creases of the skin surface divide the pattern of the basal layer into diamond-shaped areas where the imprints of the dermal papillae are to be seen. ( b ) There is great individual and regional variation in the distribution of hair follicles and sweat ducts:700 + 40 hair follicles per cm 2 were counted on the face, but only 65 + 5 in the rest of the body. The corresponding density for eccrine sweat glands was 270 + 25 in the face and 160 + 15 in the rest of the body. There are altogether about two million hair follicles and three million sweat glands in the integument. The epidermal appendages are symmetrically distributed; there is no significant difference between male and female in the density of hairs or sweat glands. The density of appendages is much higher in the foetus and in the infant than in the adult. Numerical estimates have shown that the differential rate of growth of the body surface may be solely responsible for regional differences in the density of appendages. A uniformly distributed foetal population of appendages would become ‘diluted’ three times more on the trunk and extremities than on the head during postnatal growth. The numerical ratio of sweat ducts/hair follicles is the same throughout foetal and postnatal life. ( c ) On the average there are about 1500 epidermal melanocytes/mm 2 of skin surface, excluding those in hair follicles. The total number of epidermal melanocytes in an adult is about 2000 million. They occur consistently in the basal layer of the epidermis of ‘white’ human skin (including the oral and nasal cavities). Their absolute number and their proportion to the keratinizing basal Malpighian cells are constant and characteristic in given regions. The distribution of melanocytes is also bilaterally symmetrical and their regional frequency is the same in male and female. The individual and regional variations of melanocyte distribution are, however, great. There are two or three times as many melanocytes per unit area in the epidermis of the cheek or forehead as in the other regions of the integument. Because melanocytes are mostly located on ridges, the numerical ratio of Malpighian cells/melanocytes is lower on than between the ridges. The cause of the great regional variation of melanocytes is not known. The regional differences are smaller in foetal than in adult skin. Regional differences in the degree of expansion of the body surface by growth cannot, however, explain the regional variation in the adult. Melanocyte density in the foetus is lower than in the adult, and in old epidermis a decrease in melanocyte density is one of the manifestations of ageing. Comparisons of the frequency distribution of melanocytes reveal no significant difference between the various human races. The degree of melanization of skin therefore depends not only on the number of melanocytes, but, more particularly, on their physiological activity in melanogenesis. The absolute number of melanocytes and the ratio of Malpighian cells/melanocytes are high enough to allow melanocytes to make contact with every Malpighian cell and so to disseminate melanin through the entire basal layer of the epidermis.


2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.


Author(s):  
M Mazhar Celikoyar ◽  
Michael F Perez ◽  
M Ilhan Akbas ◽  
Oguzhan Topsakal

Abstract Background Facial features and measurements are utilized to analyze patients’ faces for various reasons, including surgical planning, scientific communications, patient-surgeon communications, and post-surgery evaluations. Objectives There are numerous descriptions regarding these features and measurements scattered throughout the literature and we did not encounter a current compilation of these parameters in the medical literature. Methods A narrative literature review of the published medical literature for facial measurements used for facial analysis in rhinoplasty was done through the electronic databases MEDLINE/PubMed and Google Scholar, along with a citation search. Results A total of 61 facial features were identified. 45 points (25 bilateral, 20 unilateral), five lines (three bilateral, two unilateral), eight planes, and three areas. A total of 122 measurements were identified: 48 distances (6 bilateral, 42 unilateral), 57 angles (13 bilateral, 44 unilateral), and 17 ratios. Supplemental Figures were created to depict all features and measurements using either a frontal, lateral or basal view of the face. Conclusions This paper provides the most comprehensive and current compilation of facial measurements to date. We believe this compilation will guide further developments (methodologies and software tools) for analyzing nasal structures and assessing the objective outcomes of facial surgeries, in particular rhinoplasty. Moreover, it will improve the communication as a reference for facial measurements of facial surface anthropometry, in particular rhinoplasty.


Author(s):  
Aurora G. Vincent ◽  
Anne E. Gunter ◽  
Yadranko Ducic ◽  
Likith Reddy

AbstractAlloplastic facial transplantation has become a new rung on the proverbial reconstructive ladder for severe facial wounds in the past couple of decades. Since the first transfer including bony components in 2006, numerous facial allotransplantations across many countries have been successfully performed, many incorporating multiple bony elements of the face. There are many unique considerations to facial transplantation of bone, however, beyond the considerations of simple soft tissue transfer. Herein, we review the current literature and considerations specific to bony facial transplantation focusing on the pertinent surgical anatomy, preoperative planning needs, intraoperative harvest and inset considerations, and postoperative protocols.


Author(s):  
Swati Singh ◽  
Litesh Singla ◽  
Tanya Anand

Abstract Esthetics has been an ever-evolving concept and has gained considerable importance in the field of orthodontics in the last few decades. The re-emergence of the soft tissue paradigm has further catapulted the interest of the orthodontist. So much so that achieving a harmonious profile and an esthetically pleasing smile has become the ideal goal of treatment and is no longer secondary to achieving a functional dental occlusion and/or a rigid adherence to skeletal and dental norms. Esthetics in the orthodontic sense can be divided into three categories: macroesthetics, miniesthetics, and microesthetics. Macroesthetics includes the evaluation of the face and involves frontal assessment and profile analysis. The frontal assessment involves assessment of facial proportions, while the profile analysis involves evaluation of anterior–posterior position of jaws, mandibular plane, and incisor prominence and lip posture. Miniesthetics involves study of the smile framework involving the vertical tooth–lip relationship, smile type, transverse dimensions of smile, smile arc, and midline. Microesthetics involves the assessment of tooth proportions, height-width relationships, connectors and embrasures, gingival contours and heights, and tooth shade and color. The harmony between these factors enables an orthodontist to achieve the idealized esthetic result and hence these parameters deserve due consideration. The importance placed on a pleasing profile cannot be undermined and the orthodontist should aim for a harmonious facial profile over rigid adherence to standard average cephalometric norms. This article aims to give an overview of the macro, mini, and microesthetic considerations in relation to orthodontic diagnosis and treatment planning.


Author(s):  
Yariv Itzkovich ◽  
Ella Barhon ◽  
Rachel Lev-Wiesel

This article constructs a comprehensive theoretical model that outlines bystanders’ emotional and behavioral responses to the mistreatment of adolescent peers. The model captures bystanders’ risk and health risk behaviors, which have been overlooked in the context of their reactions; when addressed at all in connection with bystanders of bullying among adolescents, they have been treated separately. Here, we present bystanders’ emotional and cognitive reactions and their impact on bystanders’ responses including a set of responses that demonstrate risk and health risk behaviors that are directed to the bystander as a victim by proxy. The theoretical framework is the conservation of resources theory, which posits that personal resources (i.e., potency and moral disengagement) and social resources impact the process that leads to bystanders’ reactions. Previous models have overlooked the integrative viewpoint of bystanders, and comprehensive models that explain bystanders’ behavioral and emotional responses have received little attention especially with regards to adolescents. Two recent models overlooked core features embedded in the current model, including the risk and health risk behaviors that it integrates. The proposed model presents a novel and more comprehensive view of bystanders’ reactions and the process underlying these reactions. It integrates existing knowledge embedded in other existing models. At the same time, this perspective indicates the centricity of potency as a key resource that dictates the emotional response and behaviors of bystanders. This potentially allows for new applications in the mitigation of adverse impacts that follow the witnessing of mistreatment. The article discusses these applications, which are based on previous findings, their implications for practice, and directions for future empirical research necessary to validate the model.


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