Occlusion analysis

  • 文章类型: Journal Article
    像ResNet和Inception这样的深度学习架构已经为医疗保健领域的良性和恶性肿瘤分类提供了准确的预测。这使医疗机构能够做出数据驱动的决策,并可能通过采用基于计算机视觉的深度学习算法来实现恶性肿瘤的早期检测。这些CNN算法,除了需要大量的数据,可以识别在将肿瘤分类为良性或恶性时具有重要意义的较高级和较低级别的特征。然而,现有文献在结果分类的可解释性方面受到限制,并确定重要的确切特征,这在医疗保健从业者的决策过程中至关重要。因此,这项工作的动机是在卵巢肿瘤数据集上实现一个自定义分类器,它表现出很高的分类性能,随后定性地解释分类结果,使用各种可解释的人工智能方法,以识别哪些感兴趣的像素或区域被模型给予最重要的分类。数据集包括从轴向获取的卵巢肿瘤的CT扫描图像,矢状和冠状平面。国家的最先进的架构,包括从标准预训练的ResNet50派生的修改的ResNet50,在本文中实现。与现有的最先进的技术相比,提出的改进的ResNet50在测试数据集上表现出97.5%的分类准确率,而不增加架构的复杂性.然后使用几种可解释的AI技术对结果进行解释。结果表明,肿瘤的形状和局部性质对于定性确定肿瘤转移的能力以及此后被分类为良性或恶性的能力起着重要作用。
    Deep learning architectures like ResNet and Inception have produced accurate predictions for classifying benign and malignant tumors in the healthcare domain. This enables healthcare institutions to make data-driven decisions and potentially enable early detection of malignancy by employing computer-vision-based deep learning algorithms. These CNN algorithms, in addition to requiring huge amounts of data, can identify higher- and lower-level features that are significant while classifying tumors into benign or malignant. However, the existing literature is limited in terms of the explainability of the resultant classification, and identifying the exact features that are of importance, which is essential in the decision-making process for healthcare practitioners. Thus, the motivation of this work is to implement a custom classifier on the ovarian tumor dataset, which exhibits high classification performance and subsequently interpret the classification results qualitatively, using various Explainable AI methods, to identify which pixels or regions of interest are given highest importance by the model for classification. The dataset comprises CT scanned images of ovarian tumors taken from to the axial, saggital and coronal planes. State-of-the-art architectures, including a modified ResNet50 derived from the standard pre-trained ResNet50, are implemented in the paper. When compared to the existing state-of-the-art techniques, the proposed modified ResNet50 exhibited a classification accuracy of 97.5 % on the test dataset without increasing the the complexity of the architecture. The results then were carried for interpretation using several explainable AI techniques. The results show that the shape and localized nature of the tumors play important roles for qualitatively determining the ability of the tumor to metastasize and thereafter to be classified as benign or malignant.
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  • 文章类型: Journal Article
    牙科关节在牙科修复物的设计以及修复或正畸咬合的分析中至关重要。然而,常见的传统和数字咬合架在使用时是困难和麻烦的,以有效地翻译牙科铸造模型到咬合架工作空间时,使用传统的表弓。在这项研究中,我们开发了一种个性化的虚拟牙科咬合器,它直接利用计算机断层扫描(CT)数据对复杂的颌骨运动进行数学建模,提供了一种更有效和准确的方法来分析和设计牙科修复。利用CT数据,法兰克福的水平面建立了虚拟关节的数学建模,消除繁琐的脸弓转移。在牙科治疗前捕获患者的CT图像并跟踪他们的下颌运动后,颌骨跟踪信息被纳入关节数学模型。通过比较仿真数据(虚拟咬合器)和实际测量数据之间的颌骨运动,对个性化咬合方法进行了验证和分析。因此,所提出的虚拟咬合架实现了两个重要功能。首先,它通过从颅骨CT数据导出的解剖关系将数字牙模型转移到虚拟咬合器,从而取代了传统的面弓转移过程。其次,将光学跟踪提供的下颌运动轨迹纳入数学关节模型,以创建具有1.7mm小Fréchet距离的个性化虚拟关节。这种虚拟咬合器提供了一种有价值的工具,使牙医能够获得有关颞下颌关节(TMJ)的诊断信息,并为患者配置个性化的咬合分析设置。
    Dental articulation holds crucial and fundamental importance in the design of dental restorations and analysis of prosthetic or orthodontic occlusions. However, common traditional and digital articulators are difficult and cumbersome in use to effectively translate the dental cast model to the articulator workspace when using traditional facebows. In this study, we have developed a personalized virtual dental articulator that directly utilizes computed tomography (CT) data to mathematically model the complex jaw movement, providing a more efficient and accurate way of analyzing and designing dental restorations. By utilizing CT data, Frankfurt\'s horizontal plane was established for the mathematical modeling of virtual articulation, eliminating tedious facebow transfers. After capturing the patients\' CT images and tracking their jaw movements prior to dental treatment, the jaw-tracking information was incorporated into the articulation mathematical model. The validation and analysis of the personalized articulation approach were conducted by comparing the jaw movement between simulation data (virtual articulator) and real measurement data. As a result, the proposed virtual articulator achieves two important functions. Firstly, it replaces the traditional facebow transfer process by transferring the digital dental model to the virtual articulator through the anatomical relationship derived from the cranial CT data. Secondly, the jaw movement trajectory provided by optical tracking was incorporated into the mathematical articulation model to create a personalized virtual articulation with a small Fréchet distance of 1.7 mm. This virtual articulator provides a valuable tool that enables dentists to obtain diagnostic information about the temporomandibular joint (TMJ) and configure personalized settings of occlusal analysis for patients.
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  • 文章类型: Journal Article
    目的:为了确定是否使用单个或组合的机械和虚拟咬合架,以及脸弓,下巴运动跟踪器,面部扫描仪,和相关设备,实际上提高了假体在寿命和患者相关结局方面的疗效.为了尝试分析模拟和数字虚拟患者(AVP和DVP),澄清和综合与以前所谓的设备相关的术语和工作流程。
    方法:完成了涉及不同数据库的范围审查。遵循系统审查和荟萃分析(PRISMA-ScR)清单和JBI指南的首选报告项目,以提取有关人口的数据。背景和概念建立。
    结果:关于使用与AVP和DVP工作流程相关的设备和技术的功效的现有文献显示了有争议的研究设计,巨大的异质性,和可疑的质量。
    结论:术语AVP和DVP已被创造为第一步,以阐明和简化与使用机械和虚拟咬合架有关的概念和工作流程,以及脸弓,或者面部和口内扫描仪,在其他人中。此范围审查不能声称AVP方法导致更有效和高效的假体修复。
    To determine whether the use of single or combined mechanical and virtual articulators, as well as facebows, jaw motion trackers, face scanners, and related devices, actually improve the efficacy of the prosthesis obtained in terms of lifespan and patient-related outcomes. To coin the terms Analogic and Digital Virtual Patients (AVP and DVP) as an attempt to analyze, clarify and synthesize terminology and workflows related to previously so-called devices.
    A scoping review was accomplished involving different databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-ScR) checklist and JBI guidance were followed to extract data regarding the Population, Context and Concept established.
    Available literature on the efficacy of using devices and techniques related to both AVP and DVP workflows showed arguable study designs, great heterogeneity, and questionable quality.
    The terms AVP and DVP have been coined as a first step to clarify and simplify concepts and workflows related to the use of both mechanical and virtual articulators, as well as facebows, or facial and intraoral scanners, among others. This scoping review cannot claim that an AVP approach leads to more effective and efficient prosthetic restorations.
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  • 文章类型: Journal Article
    神经退行性疾病,Tau病,构成了严重的全球健康问题。这些疾病的病因尚不清楚,预计在未来30年内其发病率将增加。因此,对可能阻止这些神经退行性过程的分子机制的研究非常相关。使用机器和深度学习算法对神经退行性疾病进行分类已被广泛研究用于医学成像,例如磁共振成像。然而,患者大脑的死后免疫荧光成像研究尚未用于此目的。这些研究可以代表用于监测Tau多肽的异常化学变化或病理性翻译后修饰的有价值的工具。我们提出了一个卷积神经网络管道,用于阿尔茨海默病和进行性核上性麻痹的Tau病理学分类,方法是分析具有不同Tau生物标志物的死后免疫荧光图像,该图像使用迁移学习使用ResNet-IFT架构生成的模型进行。这些模型的输出是用可解释性算法解释的,如引导式Grad-CAM和闭塞分析。要确定最佳分类器,测试了四种不同的体系结构。我们证明了我们的设计能够对疾病进行分类,平均准确率为98.41%,同时提供了有关涉及进行性核上性麻痹和阿尔茨海默病患者大脑中存在的NFT中Tau蛋白免疫反应性的不同结构模式的正确分类的解释。
    Neurodegenerative diseases, tauopathies, constitute a serious global health problem. The etiology of these diseases is unclear and an increase in their incidence has been projected in the next 30 years. Therefore, the study of the molecular mechanisms that might stop these neurodegenerative processes is very relevant. Classification of neurodegenerative diseases using Machine and Deep Learning algorithms has been widely studied for medical imaging such as Magnetic Resonance Imaging. However, post-mortem immunofluorescence imaging studies of the brains of patients have not yet been used for this purpose. These studies may represent a valuable tool for monitoring aberrant chemical changes or pathological post-translational modifications of the Tau polypeptide. We propose a Convolutional Neural Network pipeline for the classification of Tau pathology of Alzheimer\'s disease and Progressive Supranuclear Palsy by analyzing post-mortem immunofluorescence images with different Tau biomarkers performed with models generated with the architecture ResNet-IFT using Transfer Learning. These models\' outputs were interpreted with interpretability algorithms such as Guided Grad-CAM and Occlusion Analysis. To determine the best classifier, four different architectures were tested. We demonstrated that our design was able to classify diseases with an accuracy of 98.41% on average whilst providing an interpretation concerning the proper classification involving different structural patterns in the immunoreactivity of the Tau protein in NFTs present in the brains of patients with Progressive Supranuclear Palsy and Alzheimer\'s disease.
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  • 文章类型: Journal Article
    在体内评估了三种数字咬合分析方法的可靠性和有效性。
    评估的三种方法是:扫描清晰的纸痕(SA),牙科预咬合分析系统(DP)和虚拟咬合构造方法(VO)。使用常规的硅酮透射法(ST)作为比较标准。用这四种方法测试了20个被覆盖的人类受试者中的每一个。以2周的间隔进行每种方法的复检。计算咬合接触面积(OCA)和咬合接触次数(OCN)进行分析。对于可靠性评估,比较了从每种方法获得的OCA和OCN值的组内相关系数(ICC)。对于有效性评估,皮尔逊相关系数,配对t检验,回归分析和Bland-Altman分析。
    OCA和OCN的ICC值顺序为:ST>SA>DP>VO。在ST发现了最高的OCA和OCN值,而从DP获得了最低值。当从三种数字方法获得的OCA值与ST比较时,配对t检验确定了显着差异,在DP和ST的OCN值之间。皮尔逊相关性显示ST和三种数字方法之间的系数很高(OCA为0.583-0.885;OCN为0.779-0.836)。在ST的结果与SA或VO的结果之间发现了显着的线性相关性。Bland-Altman分析表明,SA和ST的OCN值具有良好的一致性,在VO和ST之间。
    三种数字咬合分析方法在体内临床应用中具有良好的信度和效度。
    所检查的三个数字闭塞分析系统在体内定量分析中显示出良好的潜力,具有良好的信度和效度。这些分析方法的使用应促进临床实践中的数字工作流程。
    The reliability and validity of three digital occlusion analysis methods was evaluated in vivo.
    The three method evalueated were:scanning of articulating paper marks (SA), dental prescale occlusal analysis system (DP) and a virtual occlusion constructed method (VO). A conventional silicone transmission method (ST) was used as the standard for comparison. Each of the 20 enroled human subjects was tested with the four methods. Retest of each method was performed at 2-week intervals. Occlusal contact area (OCA) and occlusal contact numbers (OCN) were calculated for analyses. For reliability evaluation, intraclass correlation coefficients (ICC) of the OCA and OCN values obtained from each method were compared. For validity evaluation, Pearson correlations coefficients, paired t-tests, regression analysis and Bland-Altman analysis were examined.
    The ICC values of OCA and OCN were in the order: ST>SA>DP>VO. The highest OCA and OCN values were found ST while the lowest values were obtained from DP. Paired t-test identified a significant difference when OCA values obtained from the three digital methods were compared with ST, and between the OCN values of DP and ST. Pearson correlation showed high coefficients between ST and three digital methods (0.583-0.885 for OCA; 0.779-0.836 for OCN). A significant linear correlation was found between the results from ST and those from SA or VO. Bland-Altman analysis showed good agreement between OCN values of SA and ST, and between those of VO and ST.
    The three digital occlusal analysis methods showed good reliability and validity for in vivo clinical application.
    The three digital occlusion analysis systems examined demonstrate good potential in in vivo quantitative analysis, with good reliability and validity. The use of these analytical methods should facilitate digital workflow in clinical practice.
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  • 文章类型: Journal Article
    进行性脑萎缩是阿尔茨海默病(AD)痴呆的关键神经病理学标志。然而,AD痴呆进展过程中的萎缩模式是弥漫性的和可变的,并且经常被单变量方法所遗漏。因此,确定AD痴呆进展的主要区域萎缩模式具有挑战性.在目前的研究中,我们提出了一种评估特定区域萎缩模式预测AD痴呆进展的程度的方法,在保持所有其他萎缩变化恒定的情况下,使用总共334名受试者的样本。我们首先训练了一个密集的卷积神经网络模型,以区分进展为AD痴呆的轻度认知障碍(MCI)个体与具有稳定MCI诊断的个体。然后,我们多次重新测试了模型,每次从模型的测试集的输入中遮挡不同的感兴趣区域(ROI)。我们还通过基于Braak的分期方案遮挡ROI来验证这种方法。我们发现海马体,梭形,颞下回是AD痴呆进展的最强预测因子,与既定的分期模式一致。我们还发现,根据Braak阶段III定义的边缘ROI的闭塞对模型的性能影响最大。我们的预测模型揭示了萎缩预测AD痴呆进展的主要区域模式。这些结果强调了根据皮质萎缩模式对患有前驱AD痴呆的个体进行早期诊断和分层的潜力。在介入临床试验之前。
    Progressive brain atrophy is a key neuropathological hallmark of Alzheimer\'s disease (AD) dementia. However, atrophy patterns along the progression of AD dementia are diffuse and variable and are often missed by univariate methods. Consequently, identifying the major regional atrophy patterns underlying AD dementia progression is challenging. In the current study, we propose a method that evaluates the degree to which specific regional atrophy patterns are predictive of AD dementia progression, while holding all other atrophy changes constant using a total sample of 334 subjects. We first trained a dense convolutional neural network model to differentiate individuals with mild cognitive impairment (MCI) who progress to AD dementia versus those with a stable MCI diagnosis. Then, we retested the model multiple times, each time occluding different regions of interest (ROIs) from the model\'s testing set\'s input. We also validated this approach by occluding ROIs based on Braak\'s staging scheme. We found that the hippocampus, fusiform, and inferior temporal gyri were the strongest predictors of AD dementia progression, in agreement with established staging models. We also found that occlusion of limbic ROIs defined according to Braak stage III had the largest impact on the performance of the model. Our predictive model reveals the major regional patterns of atrophy predictive of AD dementia progression. These results highlight the potential for early diagnosis and stratification of individuals with prodromal AD dementia based on patterns of cortical atrophy, prior to interventional clinical trials.
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  • 文章类型: Journal Article
    本体外研究评估了两个计算机闭塞分析系统的可靠性和有效性。
    评价了三种闭塞分析方法。这些方法包括一种传统方法(铰接纸痕扫描(SAP))和两个计算机化系统:(牙科预咬合分析系统(DPO)和改进的虚拟咬合构造方法(VOC))。对于可靠性评估,使用三种方法中的每种方法对咬合器安装的解剖牙形的咬合进行了十次分析。获得咬合接触面积和接触数量值,并比较每种方法的变异系数(CoV)。对于有效性评估,使用10名人类受试者的牙列的树脂铸型进行分析。配对t检验,回归分析和Bland-Altman分析用于评估三种方法之间的差异和一致性。
    来自整个牙列的咬合接触区域的CoV值顺序为:SAP(5.7%)DPO和VOC均具有良好的信度和效度。它们是分析咬合接触的潜在替代品。
    牙科标前咬合分析系统和改进的虚拟咬合构建方法将方便与数字技术的客观性相结合。这些计算机闭塞分析系统可用于临床实践中咬合接触的定量分析,具有良好的信度和效度。
    The present in vitro study evaluated the reliability and validity of two computerised occlusion analysis systems.
    Three occlusion analysis methods were evaluated. The methods included one traditional method (scanning of articulating paper marks (SAP)) and two computerised systems: (dental prescale occlusion analysis system (DPO) and a modified virtual occlusion construction method (VOC)). For reliability evaluation, the occlusion of an articulator-mounted anatomical dentoform was analysed ten times with each of the three methods. Occlusal contact areas and contact number values were obtained and the coefficient of variation (CoV) of each method was compared. For validity evaluation, resin casts of the dentition of 10 human subjects were used for analysis. Paired t-tests, regression analysis and Bland-Altman analysis were used to evaluate the difference and agreement amongst the three methods.
    The CoV values of occlusal contact areas from the entire dentition were in the order: SAP (5.7%) < DPO (12.7%) < VOC (15.6%). Higher values was found in the anterior teeth (19.8-40.8%). Significant differences were identified in the occlusal contact areas of the entire dentition and posterior teeth obtained from SAP and DPO; a significant correlation was detected between the two methods (P < 0.01). Bland-Altman agreement analysis indicated good agreement between SAP and VOC.
    Both DPO and VOC have good reliability and validity. They are potential alternatives for analysis of occlusal contacts.
    The dental prescale occlusion analysis system and the modified virtual occlusion constructed method combine convenience with the objectivity of digital technology. These computerised occlusion analysis systems may be used for quantitative analysis of occlusal contacts in clinical practice, with good reliability and validity.
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  • 文章类型: Journal Article
    UNASSIGNED: Identifying the optimal method for occlusion analysis by comparing examination sensitivity of the static and dynamic occlusion using three systems: clinical occlusion analysis, semi-adjustable articulator and virtual articulator (3Shape, Denmark) occlusion analysis.
    UNASSIGNED: The occlusion analysis of sixteen patients was performed using the three systems. In order to analyze the number of concordant and discordant points and trajectories, the clinical method was compared to the semi-adjustable articulator and to the computerized method.
    UNASSIGNED: The greatest correspondence was obtained by comparing the clinical and the articulator methods, having a success rate of 85.25%, versus the clinical and the computerized method with a success rate of 73.25%. The propulsion registered the highest discrepancies: 35% in case of the semi-adjustable articulator comparison and 62% in case of the virtual articulator comparison.
    UNASSIGNED: The semi-adjustable articulator was superior in static and dynamic occlusion analysis compared to the virtual articulator. The analysis of the dynamic occlusion is the most problematic due to its dependency on the individual anatomy of the glenoid fossa which cannot be exactly reproduced by any articulator.
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