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1.
Stroke ; 52(1): 260-270, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33161843

RESUMO

BACKGROUND AND PURPOSE: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is associated with an increased rate of cerebrovascular events including ischemic stroke and intracerebral hemorrhage. The mechanisms underlying cerebral endothelial susceptibility and response to SARS-CoV-2 are unknown yet critical to understanding the association of SARS-CoV-2 infection with cerebrovascular events. METHODS: Endothelial cells were isolated from human brain and analyzed by RNA sequencing. Human umbilical vein and human brain microvascular cells were used in both monolayer culture and endothelialized within a 3-dimensional printed vascular model of the middle cerebral artery. Gene expression levels were measured by quantitative polymerase chain reaction and direct RNA hybridization. Recombinant SARS-CoV-2 S protein and S protein-containing liposomes were used to measure endothelial binding by immunocytochemistry. RESULTS: ACE2 (angiotensin-converting enzyme-2) mRNA levels were low in human brain and monolayer endothelial cell culture. Within the 3-dimensional printed vascular model, ACE2 gene expression and protein levels were progressively increased by vessel size and flow rates. SARS-CoV-2 S protein-containing liposomes were detected in human umbilical vein endothelial cells and human brain microvascular endothelial cells in 3-dimensional middle cerebral artery models but not in monolayer culture consistent with flow dependency of ACE2 expression. Binding of SARS-CoV-2 S protein triggered 83 unique genes in human brain endothelial cells including upregulation of complement component C3. CONCLUSIONS: Brain endothelial cells are susceptible to direct SARS-CoV-2 infection through flow-dependent expression of ACE2. Viral S protein binding triggers a unique gene expression profile in brain endothelia that may explain the association of SARS-CoV-2 infection with cerebrovascular events.


Assuntos
/metabolismo , Células Endoteliais/virologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Transcriptoma , Encéfalo/metabolismo , Encéfalo/virologia , Células Cultivadas , Circulação Cerebrovascular/fisiologia , Células Endoteliais/metabolismo , Humanos , Modelos Anatômicos , Estresse Mecânico
2.
J Surg Res ; 257: 344-348, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32892129

RESUMO

BACKGROUND: The movement of a double-lumen endotracheal tube (DLT) out of its appropriate position during thoracic surgery can result in the loss of one-lung ventilation (OLV), especially during pulmonary resection and node dissection. Our study aimed to validate the efficacy of automatic retention pressure control of the DLT bronchial cuff in maintaining OLV in an artificial intubation model. MATERIALS AND METHODS: A 35-Fr left-sided DLT was intubated to the left main bronchus in an intubation simulator and connected to an anesthesia machine. The inspiratory volume, respiratory rate, and inspiratory-expiratory ratio were set at 500 mL, 12 times/min, and 1:2, respectively. A 1-kg right main bronchial traction in the lateral right was provided after OLV was established. SmartCuff (Smiths Medical, Minneapolis, Minnesota, USA) was used to maintain cuff pressure. The efficacy of retention pressure with SmartCuff (Group S) and without SmartCuff (Group WS) was compared. The primary outcome was the rate of tidal volume (TV) reduction following bronchial traction in the two groups. RESULTS: The TVs were 289.8 ± 28.9 mL and 242.8 ± 31.9 mL in Group S and Group WS, respectively (P = 0.003). The rate of TV reduction after bronchial traction was significantly lower in Group S (29 ± 5%) than in Group WS (43 ± 6%) (P < 0.001). CONCLUSIONS: Automatic retention pressure control of the DLT bronchial cuff improves the rate of TV reduction during right main bronchial traction in an artificial intubation model. Continuous retention cuff pressure may be useful in maintaining OLV during thoracic surgery.


Assuntos
Intubação Intratraqueal/instrumentação , Modelos Anatômicos , Ventilação Monopulmonar , Humanos , Cirurgia Torácica Vídeoassistida , Volume de Ventilação Pulmonar
3.
Ultrasonics ; 110: 106244, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32942090

RESUMO

In this paper a high intensity focused ultrasound (FUS) phantom model was developed, in order to be used in experiments for Blood Brain Barrier (BBB) disruption. The target was to create a phantom model that represents the disruption of the BBB during ultrasound application. An appropriate experimental setup was created bearing a single element transducer with diameter 50 mm and geometric focus 100 mm operating at 0.5 MHz. It included a set of tubes and a connector with multiple 0.4 mm openings, through which a suitable liquid is being circulated with a pump. The lesions were sealed with a thin homogenous layer of wax, preventing a liquid leakage. The system was tested successfully with FUS and a liquid leakage was achieved after FUS application. This set up is the first phantom model that has the potential to be utilized as a cost-effective solution for performing experiments for BBB disruption, without the need of using animal models.


Assuntos
Barreira Hematoencefálica/anatomia & histologia , Modelos Anatômicos , Ultrassom/instrumentação , Desenho de Equipamento , Transdutores
5.
Orthop Clin North Am ; 52(1): 1-13, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33222980

RESUMO

Skills training is important in an arthroplasty curriculum and can focus either on "part tasks" or on full procedures. The most commonly used simulations in orthopedics including arthroplasty are anatomic specimens, dry bone models, and virtual or other technology-enhanced systems. A course curriculum planning committee must identify the gaps to address, define what learners need to be able to do, and select the most appropriate simulation modality and assessment for delivery. Each simulation must have a clear structure with learning objectives, steps, and take-home messages. Feedback from learners and faculty must be integrated to improve processes and models for future learning.


Assuntos
Artroplastia de Quadril/educação , Artroplastia do Joelho/educação , Competência Clínica , Currículo , Ortopedia/educação , Cadáver , Simulação por Computador , Humanos , Modelos Anatômicos
6.
GMS J Med Educ ; 37(7): Doc87, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33364366

RESUMO

Objective: Primary outcome of this retrospective study was the comparison of state examination results under simulated treatment conditions in times of Covid-19 versus patient treatment under non-pandemic conditions. Additionally, correlation analysis was performed between students' self- and examiners' assessment of the treatment results. Methods: Within 4 hours, 22 examinees each had to place a multi-surface adhesive anterior and posterior restoration, performed an endodontic treatment on a maxillary premolar and a periodontal debridement of one quadrant. All treatments were performed on a model fixed in a phantom head. Compliance with the prescribed hygiene and social distancing guidelines and self-assessment of the practical performance was part of the practical examination as well. One examiner per examination part evaluated anonymously the final results. The historical control was based on the exam results of a cohort from 2019. Mean values (standard deviation), non-parametric correlations (Spearman's Rho) and group comparisons (Mann-Whitney) were calculated for statistical analysis. Results: Examination results under simulated treatment conditions were significantly worse (p<0.05) than in the cohort that took their state exam in patients, with exception of the endodontic partial exam. The overall scores in restorative dentistry and periodontology of both groups, which include a structured theoretical examination, did not differ. The majority of the candidates rated their performance worse than the examiners, and there was no correlation between self- and third-party assessment. Conclusion: In the comparison of two years, a simulated practical examination without patients in restorative dentistry, endodontics and periodontology resulted in matchable results compared with an examination on patients. Equal conditions for the candidates resulting in better comparability and avoidance of ethical dilemmas of patient treatment under examination conditions could also be arguments towards a state examination under phantom conditions in the future.


Assuntos
/epidemiologia , Educação em Odontologia/organização & administração , Educação a Distância/organização & administração , Avaliação Educacional/estatística & dados numéricos , Odontólogos/educação , Educação em Odontologia/normas , Educação a Distância/normas , Avaliação Educacional/normas , Endodontia/educação , Humanos , Modelos Anatômicos , Pandemias , Autoavaliação , Estudantes de Odontologia
7.
Clin Dermatol ; 38(5): 555-562, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33280803

RESUMO

Wax models have occupied a unique position in the teaching of dermatology. The wax model offers a unique presentation of the morphology, often not captured by other methods. Much has already been written about the unfortunate fate of many of these collections. Some models went to historical collections, a few were saved to continue their didactic purpose, and still others met their untimely demise. There has been renewed interest in the preservation of these models in recent years, from dermatologists and historians alike, and this has led to increasing efforts to document the origin, migration, exhibition, and maintenance of these collections. Our mission for this study is to report on our findings of the existence and whereabouts of dermatologic wax models since the 1990 survey. Even with the advent of the Internet and interest generated for preserving these wonderful illustrations of dermatologic conditions, many collections have remained unknown or dismantled. In the end, wax models have survived the introduction of hand-colored artist's renditions, color photography, and even computerized illustrations. Although no longer the premier teaching tool of yesteryear, their survival reflects upon the development of dermatology and the initial transition from hand-colored prints to our current digital-oriented age.


Assuntos
Dermatologia/educação , Dermatologia/tendências , Educação Médica/métodos , Educação Médica/tendências , Modelos Anatômicos , Dermatopatias , Materiais de Ensino , Ceras , Humanos , América do Norte
8.
PLoS One ; 15(12): e0242704, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33351854

RESUMO

In this study we present a kinematic approach for modeling needle insertion into soft tissues. The kinematic approach allows the presentation of the problem as Dirichlet-type (i.e. driven by enforced motion of boundaries) and therefore weakly sensitive to unknown properties of the tissues and needle-tissue interaction. The parameters used in the kinematic approach are straightforward to determine from images. Our method uses Meshless Total Lagrangian Explicit Dynamics (MTLED) method to compute soft tissue deformations. The proposed scheme was validated against experiments of needle insertion into silicone gel samples. We also present a simulation of needle insertion into the brain demonstrating the method's insensitivity to assumed mechanical properties of tissue.


Assuntos
Injeções/estatística & dados numéricos , Modelos Estatísticos , Agulhas , Silicones/análise , Fenômenos Biomecânicos , Encéfalo/anatomia & histologia , Simulação por Computador , Humanos , Injeções/instrumentação , Injeções/métodos , Manequins , Modelos Anatômicos , Silicones/química , Estresse Mecânico
9.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 76(12): 1281-1286, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-33342947

RESUMO

In radiological examinations of patients, we often take stacked images and three-dimensional (3D) images of human bone radiological images such as X-ray images and CT images. In general, learning of bone structure using specialized anatomy books is currently performed at medical radiological technologist education facilities. In the anatomy education of the medical school, in order to understand the structure of human and the individual bone shapes in detail, a real human bone specimen is used to gain knowledge of skeleton, bone shape, bone name and bone function. But it is actually difficult for a radiological technologist to obtain such learning opportunities. Therefore, we had to depend on two-dimensional information from an anatomical atlas so far. Therefore, as a method to solve this, we devised this stereo-paired bone anatomical chart by stereoscopic photography of a real human bone specimen that is available only in the anatomy laboratory. In classical anatomy textbooks, there are no figures that enable us to view 3D structures of human bones. Our stereo-paired bone anatomical charts make it possible to observe accurate bone structures three-dimensionally. In addition, we saved the data as a PDF file and uploaded to an internet server so that we can freely download and readily observe 3D images of human bones at all times and all places with a tablet or a PC monitor.


Assuntos
Imageamento Tridimensional , Radiação , Compreensão , Humanos , Aprendizagem , Modelos Anatômicos
10.
Aging (Albany NY) ; 12(22): 22425-22444, 2020 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-33221759

RESUMO

With the current COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for new therapies and prevention strategies that can help curtail disease spread and reduce mortality. The inhibition of viral entry and thus spread is a plausible therapeutic avenue. SARS-CoV-2 uses receptor-mediated entry into a human host via the angiotensin-converting enzyme 2 (ACE2), which is expressed in lung tissue as well as the oral and nasal mucosa, kidney, testes and gastrointestinal tract. The modulation of ACE2 levels in these gateway tissues may be an effective strategy for decreasing disease susceptibility. Cannabis sativa, especially those high in the anti-inflammatory cannabinoid cannabidiol (CBD), has been found to alter gene expression and inflammation and harbour anti-cancer and anti-inflammatory properties. However, its effects on ACE2 expression remain unknown. Working under a Health Canada research license, we developed over 800 new C. sativa cultivars and hypothesized that high-CBD C. sativa extracts may be used to down-regulate ACE2 expression in target COVID-19 tissues. Using artificial 3D human models of oral, airway and intestinal tissues, we identified 13 high-CBD C. sativa extracts that decrease ACE2 protein levels. Some C. sativa extracts down-regulate serine protease TMPRSS2, another critical protein required for SARS-CoV-2 entry into host cells. While our most effective extracts require further large-scale validation, our study is important for future analyses of the effects of medical cannabis on COVID-19. The extracts of our most successful novel high-CBD C. sativa lines, pending further investigation, may become a useful and safe addition to the prevention/treatment of COVID-19 as an adjunct therapy.


Assuntos
/antagonistas & inibidores , Cannabis/química , Extratos Vegetais/farmacologia , /efeitos dos fármacos , /metabolismo , /epidemiologia , Canabidiol/farmacologia , Canabidiol/uso terapêutico , Simulação por Computador , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/virologia , Modelos Anatômicos , Mucosa Bucal/efeitos dos fármacos , Mucosa Bucal/metabolismo , Mucosa Bucal/virologia , Pandemias/prevenção & controle , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo , Mucosa Respiratória/virologia , /patogenicidade , Internalização do Vírus/efeitos dos fármacos
11.
Am J Sports Med ; 48(14): 3557-3565, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33135907

RESUMO

BACKGROUND: Adult medial patellofemoral ligament (MPFL) reconstruction techniques are not appropriate for the skeletally immature patient given the proximity of the distal femoral physis. Biomechanical consequences of reconstructions aimed at avoiding the physis have not been adequately studied. PURPOSE: To quantify the biomechanical effects of MPFL reconstruction techniques intended for skeletally immature patients. STUDY DESIGN: Controlled laboratory study. METHODS: Four MPFL reconstruction techniques were evaluated using a computationally augmented cadaveric model: (1) Schoettle point: adult-type reconstruction; (2) epiphyseal: socket distal to the femoral physis; (3) adductor sling: graft wrapped around the adductor tendon; (4) adductor transfer: adductor tendon transferred to patella. A custom testing frame was used to cycle 8 knees for each technique from 10° to 110° of flexion. Patellofemoral kinematics were recorded using a motion camera system, contact stresses were recorded using Tekscan pressure sensors, and MPFL length was computed using an inverse kinematics computational model. Change in MPFL length, patellar facet forces, and patellar kinematics were compared using generalized estimating equation modeling. RESULTS: Schoettle point reconstruction was the most isometric, demonstrating isometry from 10° to 100°. The epiphyseal technique was isometric until 60°, after which the graft loosened with increasing flexion. The adductor sling and adductor transfer techniques were significantly more anisometric from 40° to 110°. Both grafts tightened with knee flexion and resulted in significantly more lateral patellar tilt versus the intact state in early flexion and significantly higher contact forces on the medial facet versus the epiphyseal technique in late flexion. CONCLUSION: In this cadaveric simulation, the epiphyseal technique allowed for a more isometric ligament until midflexion, when the patella engaged within the trochlear groove. The adductor sling and adductor transfer grafts became tighter in flexion, resulting in potential loss of motion, pain, graft stretching, and failure. Marginal between-condition differences in patellofemoral contact mechanics and patellar kinematics were observed in late flexion. CLINICAL RELEVANCE: In the skeletally immature patient, using an epiphyseal type MPFL reconstruction with the femoral attachment site distal to the physis results in a more isometric graft compared with techniques with attachment sites proximal to the physis.


Assuntos
Ligamentos Articulares/cirurgia , Modelos Anatômicos , Articulação Patelofemoral , Adulto , Idoso , Cadáver , Humanos , Pessoa de Meia-Idade , Patela , Articulação Patelofemoral/cirurgia , Procedimentos Cirúrgicos Reconstrutivos , Tendões
12.
Proc Natl Acad Sci U S A ; 117(48): 30159-30170, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33188087

RESUMO

Reef-building corals and their aragonite (CaCO3) skeletons support entire reef ecosystems, yet their formation mechanism is poorly understood. Here we used synchrotron spectromicroscopy to observe the nanoscale mineralogy of fresh, forming skeletons from six species spanning all reef-forming coral morphologies: Branching, encrusting, massive, and table. In all species, hydrated and anhydrous amorphous calcium carbonate nanoparticles were precursors for skeletal growth, as previously observed in a single species. The amorphous precursors here were observed in tissue, between tissue and skeleton, and at growth fronts of the skeleton, within a low-density nano- or microporous layer varying in thickness from 7 to 20 µm. Brunauer-Emmett-Teller measurements, however, indicated that the mature skeletons at the microscale were space-filling, comparable to single crystals of geologic aragonite. Nanoparticles alone can never fill space completely, thus ion-by-ion filling must be invoked to fill interstitial pores. Such ion-by-ion diffusion and attachment may occur from the supersaturated calcifying fluid known to exist in corals, or from a dense liquid precursor, observed in synthetic systems but never in biogenic ones. Concomitant particle attachment and ion-by-ion filling was previously observed in synthetic calcite rhombohedra, but never in aragonite pseudohexagonal prisms, synthetic or biogenic, as observed here. Models for biomineral growth, isotope incorporation, and coral skeletons' resilience to ocean warming and acidification must take into account the dual formation mechanism, including particle attachment and ion-by-ion space filling.


Assuntos
Antozoários/anatomia & histologia , Osso e Ossos/anatomia & histologia , Animais , Antozoários/ultraestrutura , Recifes de Corais , Íons , Modelos Anatômicos , Nanopartículas/química
13.
Plast Reconstr Surg ; 146(6): 1407-1417, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33234980

RESUMO

BACKGROUND: The iPhone X (Apple, Inc., Cupertino, Calif.) is the first smartphone to be released with a high-fidelity three-dimensional scanner. At present, half of all U.S. smartphone users use an iPhone. Recent data suggest that the majority of these 230 million individuals will upgrade to the iPhone X within 2 years. This represents a profound expansion in access to three-dimensional scanning technology, not only for plastic surgeons but for their patients as well. The purpose of this study was to compare the iPhone X scanner against a popular, portable three-dimensional camera used in plastic surgery (Canfield Vectra H1; Canfield Scientific, Inc., Parsippany, N.J.). METHODS: Sixteen human subjects underwent three-dimensional facial capture with the iPhone X and Canfield Vectra H1. Results were compared using color map analysis and surface distances between key anatomical landmarks. To assess repeatability and precision of the iPhone X three-dimensional scanner, six facial scans of a single participant were obtained and compared using color map analysis. In addition, three-dimensionally-printed facial masks (n = 3) were captured with each device and compared. RESULTS: For the experiments, average root mean square was 0.44 mm following color map analysis and 0.46 mm for surface distance between anatomical landmarks. For repeatability and precision testing, average root mean square difference following color map analysis was 0.35 mm. For the three-dimensionally-printed facial mask comparison, average root mean square difference was 0.28 mm. CONCLUSIONS: The iPhone X offers three-dimensional scanning that is accurate and precise to within 0.5 mm when compared to a commonly used, validated, and expensive three-dimensional camera. This represents a significant reduction in the barrier to access to three-dimensional scanning technology for both patients and surgeons.


Assuntos
Face/diagnóstico por imagem , Imageamento Tridimensional/instrumentação , Planejamento de Assistência ao Paciente/economia , Procedimentos Cirúrgicos Reconstrutivos , Smartphone/economia , Adulto , Face/cirurgia , Feminino , Humanos , Imageamento Tridimensional/economia , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos , Impressão Tridimensional , Reprodutibilidade dos Testes , Adulto Jovem
14.
PLoS Biol ; 18(11): e3000979, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33253185

RESUMO

The vast net of fibres within and underneath the cortex is optimised to support the convergence of different levels of brain organisation. Here, we propose a novel coordinate system of the human cortex based on an advanced model of its connectivity. Our approach is inspired by seminal, but so far largely neglected models of cortico-cortical wiring established by postmortem anatomical studies and capitalises on cutting-edge in vivo neuroimaging and machine learning. The new model expands the currently prevailing diffusion magnetic resonance imaging (MRI) tractography approach by incorporation of additional features of cortical microstructure and cortico-cortical proximity. Studying several datasets and different parcellation schemes, we could show that our coordinate system robustly recapitulates established sensory-limbic and anterior-posterior dimensions of brain organisation. A series of validation experiments showed that the new wiring space reflects cortical microcircuit features (including pyramidal neuron depth and glial expression) and allowed for competitive simulations of functional connectivity and dynamics based on resting-state functional magnetic resonance imaging (rs-fMRI) and human intracranial electroencephalography (EEG) coherence. Our results advance our understanding of how cell-specific neurobiological gradients produce a hierarchical cortical wiring scheme that is concordant with increasing functional sophistication of human brain organisation. Our evaluations demonstrate the cortical wiring space bridges across scales of neural organisation and can be easily translated to single individuals.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Conectoma/métodos , Adulto , Encéfalo/diagnóstico por imagem , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Imagem de Difusão por Ressonância Magnética , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/fisiopatologia , Eletrocorticografia , Epilepsias Parciais/diagnóstico por imagem , Epilepsias Parciais/patologia , Epilepsias Parciais/fisiopatologia , Feminino , Neuroimagem Funcional , Humanos , Aprendizado de Máquina , Masculino , Modelos Anatômicos , Modelos Neurológicos , Rede Nervosa/anatomia & histologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiologia , Adulto Jovem
15.
BMC Surg ; 20(1): 264, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33129303

RESUMO

BACKGROUND: It is rare that drains cannot be removed after surgery, however, this situation cannot be completely avoided, and is also hard to deal with. The main reason for a tethered drain is inadvertent suture fixation. At present, no effective way was published or widely accepted to locate the tethered drain. METHODS: Three cases of orthopedic trauma patients experienced unsuccessful removal of the drain after surgery. The ultrasound was used to locate the sutured site of the drain. Based on the sliding sign and vanishing point which can be detected by the ultrasound, the sutured site of the drain can be clearly identified. Finally, the suture was loosened through a small incision, and the drain was completely removed. RESULTS: The surgical procedure was very successful in all patients. The tethered drain was quickly and completely removed through a small incision with locating by ultrasound. Intravenous antibiotics were administered within 24 h after surgery, and no wound or deep infections occurred. CONCLUSIONS: Ultrasound can be used to locate a tethered drain based on the sliding sign. This method can simplify the release procedure and achieve fast removal of the drain. Furthermore, it will help lower the risk of a retained drain and soft tissue complications.


Assuntos
Remoção de Dispositivo , Drenagem , Corpos Estranhos/diagnóstico por imagem , Procedimentos Ortopédicos/efeitos adversos , Técnicas de Sutura/efeitos adversos , Ultrassonografia , Adulto , Animais , Remoção de Dispositivo/métodos , Drenagem/instrumentação , Feminino , Corpos Estranhos/etiologia , Corpos Estranhos/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos , Procedimentos Ortopédicos/métodos , Suturas/efeitos adversos , Suínos
16.
Plast Reconstr Surg ; 146(5): 1012-1014, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33136944

RESUMO

Traditional ways of visualizing the differences between male and female faces are often based on single-subject exemplars or artist depictions of hypermasculine and hyperfeminine faces. By equalizing the sizes of male and female facial averages, the authors analyzed the influences of intrinsic shape and size on the architecture of the face.


Assuntos
Face/anatomia & histologia , Adulto , Feminino , Humanos , Imageamento Tridimensional , Masculino , Modelos Anatômicos , Tamanho do Órgão , Caracteres Sexuais
17.
Plast Reconstr Surg ; 146(5): 1100-1102, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33136955

RESUMO

Reduced work hours and funding have fueled an increase in simulation-based training for plastic and orthopedic surgery residency programs. Unfortunately, certain simulation training can fail to enhance surgical skills because of availability, cost, or low fidelity. There is a growing interest among training programs for a cost-effective surgical simulator to improve basic skills and muscle memory of residents. The authors developed a three-dimensionally-printed, malleable, and anatomically accurate hand surgery simulator from a computed tomographic scan of an adult male subject. The bone matrix was specifically designed to provide proprioceptive feedback to hone drilling skills used in fracture repair and arthrodesis. The silicone soft-tissue covering provides excellent malleability to dissect and perform fracture-reducing maneuvers. Three-dimensional printing of "fracture bridges" allows the design of on-demand polyfracture models so the trainee can practice multiple types and locations of repairs as skills progress. To summarize, the authors' hand simulator is an anatomical, low-cost, multiprocedure tool that can be used to improve the muscle memory and basic surgery skills of residents in training.


Assuntos
Mãos/cirurgia , Internato e Residência/métodos , Modelos Anatômicos , Ortopedia/educação , Impressão Tridimensional , Treinamento por Simulação , Cirurgia Plástica/educação , Adulto , Humanos , Masculino
18.
Am J Gastroenterol ; 115(11): 1906-1910, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33156110

RESUMO

INTRODUCTION: The purpose of this study was to find out whether 3-dimensional (3D)-printed models improved the learners' ability to identify liver segments. METHODS: A total of 116 physicians from 3 disciplines were tested in a cross-over trial at baseline and after teaching with 3D models and 2-dimensional (2D) images. Adjusted multilevel-mixed models were used to compare scores at baseline and after 3D and 2D. RESULTS: Accuracy in identifying hepatic segments was higher with 3D first than 2D (77% vs 69%; P = 0.05) and not significantly improved by a combination of 3D and 2D. Increased confidence in segment identification was highest in trainees after 3D (P = 0.04). DISCUSSION: 3D-printed models facilitate learning hepatic segmental anatomy.


Assuntos
Anatomia/educação , Gastroenterologia/educação , Cirurgia Geral/educação , Fígado/anatomia & histologia , Modelos Anatômicos , Impressão Tridimensional , Radiologia/educação , Adulto , Competência Clínica , Estudos Cross-Over , Feminino , Humanos , Fígado/diagnóstico por imagem , Masculino , Distribuição Aleatória , Tomografia Computadorizada por Raios X , Adulto Jovem
19.
PLoS One ; 15(10): e0241589, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33125441

RESUMO

Implant-retained custom-milled framework enhances the stability of palatal obturator prostheses. Therefore, to evaluate the mechanical response of implant-retained obturator prostheses with bar-clip attachment and milled bars, in three different materials under two load incidences were simulated. A maxilla model which Type IIb maxillary defect received five external hexagon implants (4.1 x 10 mm). An implant-supported palatal obturator prosthesis was simulated in three different materials: polyetheretherketone (PEEK), titanium (Ti:90%, Al:6%, V:4%) and Co-Cr (Co:60.6%, Cr:31.5%, Mo:6%) alloys. The model was imported into the analysis software and divided into a mesh composed of nodes and tetrahedral elements. Each material was assumed isotropic, elastic and homogeneous and all contacts were considered ideal. The bone was fixed and the load was applied in two different regions for each material: at the palatal face (cingulum area) of the central incisors (100 N magnitude at 45°); and at the occlusal surface of the first left molar (150 N magnitude normal to the surface). The microstrain and von-Mises stress were selected as criteria for analysis. The posterior load showed a higher strain concentration in the posterior peri-implant tissue, near the load application side for cortical and cancellous bone, regardless the simulated material. The anterior load showed a lower strain concentration with reduced magnitude and more implants involving in the load dissipation. The stress peak was calculated during posterior loading, which 77.7 MPa in the prosthetic screws and 2,686 µÎµ microstrain in the cortical bone. For bone tissue and bar, the material stiffness was inversely proportional to the calculated microstrain and stress. However, for the prosthetic screws and implants the PEEK showed higher stress concentration than the other materials. PEEK showed a promising behavior for the bone tissue and for the integrity of the bar and bar-clip attachments. However, the stress concentration in the prosthetic screws may represent an increase in failure risk. The use of Co-Cr alloy can reduce the stress in the prosthetic screw; however, it increases the bone strain; while the Titanium showed an intermediate behavior.


Assuntos
Materiais Dentários/química , Maxila/cirurgia , Obturadores Palatinos , Fenômenos Biomecânicos , Ligas de Cromo/química , Humanos , Cetonas/química , Teste de Materiais , Maxila/anatomia & histologia , Modelos Anatômicos , Polietilenoglicóis/química , Estresse Mecânico , Titânio/química
20.
PLoS One ; 15(10): e0240508, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33064731

RESUMO

OBJECTIVES: This study aimed to evaluate the marginal and internal gaps in 3D-printed interim crowns made from digital models of cone-beam computed tomography (CBCT) conversion data. MATERIALS AND METHODS: Sixteen polyvinylsiloxane impressions were taken from patients for single crown restorations and were scanned using CBCT. The scanning data were converted to positive Standard Triangulation Language (STL) files using custom-developed software. The fabricated stone models were scanned with an intraoral optical scanner (IOS) to compare the surface accuracy with the STL data obtained by CBCT. The converted STL files were utilized to fabricate interim crowns with a photopolymer using a digital light-processing 3D printer. The replica method was used to analyze the accuracy. The marginal and internal gaps in the replica specimen of each interim crown were measured with a digital microscope. The Friedman test and Mann-Whitney U test (Wilcoxon-signed rank test) were conducted to compare the measurements of the marginal and internal gaps with a 95% level of confidence. RESULTS: The root-mean-square values of the CBCT and IOS ranged from 41.00 to 126.60 µm, and the mean was 60.12 µm. The mean values of the marginal, internal, and total gaps were 132.96 (±139.23) µm, 137.86 (±103.09) µm, and 135.68 (±120.30) µm, respectively. There were no statistically significant differences in the marginal or internal gaps between the mesiodistal and buccolingual surfaces, but the marginal area (132.96 µm) and occlusal area (255.88 µm) had significant mean differences. CONCLUSION: The marginal gap of the fabricated interim crowns based on CBCT STL data was within the acceptable range of clinical success. Through ongoing developments of high-resolution CBCT and the digital model conversion technique, CBCT might be an alternative method to acquire digital models for interim crown fabrication.


Assuntos
Materiais para Moldagem Odontológica/química , Planejamento de Prótese Dentária/métodos , Polivinil/química , Siloxanas/química , Humanos , Modelos Anatômicos , Impressão Tridimensional , Software , Tomografia Computadorizada de Feixe Cônico Espiral/instrumentação
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