Layer-selective deep representation to improve esophageal cancer classification.

Even though artificial intelligence and machine learning have demonstrated remarkable performances in medical image computing, their accountability and transparency level must be improved to transfer this success into clinical practice. The reliability of machine learning decisions must be explained and interpreted, especially for supporting the medical diagnosis. For this task, the deep learning techniques' black-box nature must somehow be lightened up to clarify its promising results. Hence, we aim to investigate the impact of the ResNet-50 deep convolutional design for Barrett's esophagus and adenocarcinoma classification. For such a task, and aiming at proposing a two-step learning technique, the output of each convolutional layer that composes the ResNet-50 architecture was trained and classified for further definition of layers that would provide more impact in the architecture. We showed that local information and high-dimensional features are essential to improve the classification for our task. Besides, we observed a significant improvement when the most discriminative layers expressed more impact in the training and classification of ResNet-50 for Barrett's esophagus and adenocarcinoma classification, demonstrating that both human knowledge and computational processing may influence the correct learning of such a problem.

Facial expressions to identify post-stroke: A pilot study.

BACKGROUND AND OBJECTIVE: Timely stroke treatment can limit brain damage and improve outcomes, which depends on early recognition of the symptoms. However, stroke cases are often missed by the first respondent paramedics. One of the earliest external symptoms of stroke is based on facial expressions. METHODS: We propose a computerized analysis of facial expressions using action units to distinguish between Post-Stroke and healthy people. Action units enable analysis of subtle and specific facial movements and are interpretable to the facial expressions. The RGB videos from the Toronto Neuroface Dataset, which were recorded during standard orofacial examinations of 14 people with post-stroke (PS) and 11 healthy controls (HC) were used in this study. Action units were computed using XGBoost which was trained using HC, and classified using regression analysis for each of the nine facial expressions. The analysis was performed without manual intervention. RESULTS: The results were evaluated using leave-one-our validation. The accuracy was 82% for Kiss and Spread, with the best sensitivity of 91% in the differentiation of PS and HC. The features corresponding to mouth muscles were most suitable. CONCLUSIONS: This pilot study has shown that our method can detect PS based on two simple facial expressions. However, this needs to be tested in real-world conditions, with people of different ethnicities and smartphone use. The method has the potential for a computerized assessment of the videos for use by the first respondents using a smartphone to perform screening tests, which can facilitate the timely start of the treatment.

Tabular data augmentation for video-based detection of hypomimia in Parkinson's disease.

BACKGROUND AND OBJECTIVE: This paper presents a method for the computerized detection of hypomimia in people with Parkinson's disease (PD). It overcomes the difficulty of the small and unbalanced size of available datasets. METHODS: A public dataset consisting of features of the video recordings of people with PD with four facial expressions was used. Synthetic data was generated using a Conditional Generative Adversarial Network (CGAN) for training augmentation. After training the model, Test-Time Augmentation was performed. The classification was conducted using the original test set to prevent bias in the results. RESULTS: The employment of CGAN followed by Test-Time Augmentation led to an accuracy of classification of the videos of 83%, specificity of 82%, and sensitivity of 85% in the test set that the prevalence of PD was around 7% and where real data was used for testing. This is a significant improvement compared with other similar studies. The results show that while the technique was able to detect people with PD, there were a number of false positives. Hence this is suitable for applications such as population screening or assisting clinicians, but at this stage is not suitable for diagnosis. CONCLUSIONS: This work has the potential for assisting neurologists to perform online diagnose and monitoring their patients. However, it is essential to test this for different ethnicity and to test its repeatability.

The natural CAD/CAM anterior implant single tooth restoration: A novel digital workflow.

OBJECTIVE: To report a novel digital workflow to replace an anterior maxillary tooth lost due to trauma with an implant multilayer restoration by using the patient's extracted tooth as a final crown restoration using computer-aided design/computer-aided manufacturing (CAD/CAM) technology. CLINICAL CONSIDERATIONS: Instead of using the patient's natural tooth as an immediate provisional restoration to achieve predictable results in terms of esthetics and soft tissue structure, a novel digital strategy was performed to obtain a natural final crown restoration by using the patient's tooth associated with a lithium disilicate customized implant abutment. CONCLUSIONS: The perspective of using this strategic approach for implant restorative dental treatments in patients with traumatic root fractures in the anterior region has great potential as it helps to maintain the emergence profile of the natural dentition and esthetics. CLINICAL SIGNIFICANCE: Optimal esthetic outcomes are challenging in implant dentistry regarding soft tissue structure and morphology factors. Using natural teeth from surgery to deliver the final restoration might be beneficial when an anterior tooth is lost due to trauma.

Primer caso, en un estado brasileño, de tratamiento quirúrgico de una fractura distal de clavícula con placa bloqueada con un botón pegado asociado a otro botón subcoracoideo asistido por artroscopía / First case, in a Brazilian state, of surgical treatment of a distal clavicle fracture with a plate locked with a glued button associated with another subcoracoid button assisted by arthroscopy

El tratamiento de las fracturas de clavícula distal se puede lograr a través de varias opciones. Las placas de bloqueo asociadas con los botones coracoclaviculares son una alternativa para estabilizar las lesiones de ligamentos asociadas con las fracturas de tipo IIB de Craig. La artroscopía puede ayudar a colocar el botón subcoracoideo. Presentamos el caso de una mujer de treinta y cinco años quien, al caer de una bicicleta, resultó con traumatismo directo en el hombro izquierdo. Las radiografías mostraron fractura conminuta de la clavícula distal asociada con lesiones de ligamentos (tipo IIB de Craig). Se optó por tratamiento quirúrgico con placa bloqueada con un botón pegado asociado a otro botón subcoracoideo asistido por artroscopía. A través de una vía de acceso directo sobre la clavícula mediolateral, se redujeron anatómicamente los fragmentos de fractura y se fijaron con una placa bloqueada para la clavícula distal y siete tornillos. Se realizó portal artroscópico posterior para visualizar la articulación. Mediante portal anterior se expusieron el espacio rotador y la región subcoracoidea. Con la ayuda de guías especiales se instalaron dos botones (uno subcoracoideo y otro pegado a la placa) conectados por cables especiales. Tres meses después de la cirugía, la paciente estaba sin dolor y volvió a practicar deportes al nivel previo a la lesión. Se logró un ROM normal y radiografías con la fractura anatómicamente consolidada y distancia coracoclavicular normal. Nivel de Evidencia: IV

The treatment of distal clavicle fractures can be accomplished through several options. Locking plates associated with coracoclavicular buttons are an alternative to stabilize ligament injuries associated with Craig's type IIB fractures. Arthroscopy can assist in positioning the subcoracoid dog button.We present the case of a thirty-five-year-old female fell from a bicycle with direct trauma to her left shoulder. Radiographs showed comminuted fracture of the distal clavicle associated with ligament injuries (Craig's type IIB). We opted for surgical treatment with a locked plate with a coupled button associated with a subcoracoid dog bone, assisted by arthroscopy. Through a direct region route over the mediolateral clavicle, the fracture fragments were anatomically reduced and fixed with a locked plate for the distal clavicle and seven screws. Posterior arthroscopic portal was performed to visualize the joint. Anterior portal was performed and the rotator space and subcoracoid region was exposed. With the aid of special guides, two buttons were installed (one sub-coracoid button and other attached to the plate) connected by special wires ("tapes"). Three months after the surgery, the patient was pain-free and returned to sports at the level prior to the injury. Normal ROM was achieved and radiographs with the anatomically consolidated fracture and normal coracoclavicular distance. Level of Evidence: IV

Digital impressions' accuracy through "cut-out-rescan" and "data exchange by over scanning" techniques in complete arches of two intraoral scanners and CAD/CAM software.

PURPOSE: This technical procedure describes the accuracy of "cut-out-rescan" and "data exchange by over scanning" on cast areas using computer-aided design and computer-aided manufacturing software and two intraoral scanners (IOSs). METHODS: A customized cast was used as a reference standard and scanned using an ATOS Triple Scan digitizer. Two IOS setups were used in three scanning groups, namely, the control, cut-out-rescan, and data exchange by over scanning groups. Sixty digital files (n = 10 per group) were obtained and converted into the standard tessellation language format. A metrology program was used to evaluate the difference in accuracy between the control group and the other groups using Welch's unequal variances t-test. CONCLUSION: For trueness and precision of complete arch scans, the present technique provides statistical evidence that using data exchange by over scanning and a Primescan IOS results in higher accuracy scans compared to using cut-out-rescan and a Primescan IOS. The cut-out-rescan procedure provides scans with higher accuracy when using an Omnicam IOS. This technique is simple and saves time in workflows using a Primescan IOS.

Computer-assisted Parkinson's disease diagnosis using fuzzy optimum- path forest and Restricted Boltzmann Machines.

Parkinson's disease (PD) is a progressive neurodegenerative illness associated with motor skill disorders, affecting thousands of people, mainly elderly, worldwide. Since its symptoms are not clear and commonly confused with other diseases, providing early diagnosis is a challenging task for traditional methods. In this context, computer-aided assistance is an alternative method for a fast and automatic diagnosis, accelerating the treatment and alleviating an excessive effort from professionals. Moreover, the most recent studies proposing a solution to this problem lack in computational efficiency, prediction power, reliability among other factors. Therefore, this work proposes a Fuzzy Optimum Path Forest for automated PD identification, which is based on fuzzy logic and graph-based framework theory. Experiments consider a dataset composed of features extracted from hand-drawn images using Restricted Boltzmann Machines, and results are compared with baseline models such as Support Vector Machines, KNN, and the standard OPF classifier. Results show that the proposed model outperforms the baselines in most cases, suggesting the Fuzzy OPF as a viable alternative to deal with PD detection problems.

Assisting Barrett's esophagus identification using endoscopic data augmentation based on Generative Adversarial Networks.

Barrett's esophagus figured a swift rise in the number of cases in the past years. Although traditional diagnosis methods offered a vital role in early-stage treatment, they are generally time- and resource-consuming. In this context, computer-aided approaches for automatic diagnosis emerged in the literature since early detection is intrinsically related to remission probabilities. However, they still suffer from drawbacks because of the lack of available data for machine learning purposes, thus implying reduced recognition rates. This work introduces Generative Adversarial Networks to generate high-quality endoscopic images, thereby identifying Barrett's esophagus and adenocarcinoma more precisely. Further, Convolution Neural Networks are used for feature extraction and classification purposes. The proposed approach is validated over two datasets of endoscopic images, with the experiments conducted over the full and patch-split images. The application of Deep Convolutional Generative Adversarial Networks for the data augmentation step and LeNet-5 and AlexNet for the classification step allowed us to validate the proposed methodology over an extensive set of datasets (based on original and augmented sets), reaching results of 90% of accuracy for the patch-based approach and 85% for the image-based approach. Both results are based on augmented datasets and are statistically different from the ones obtained in the original datasets of the same kind. Moreover, the impact of data augmentation was evaluated in the context of image description and classification, and the results obtained using synthetic images outperformed the ones over the original datasets, as well as other recent approaches from the literature. Such results suggest promising insights related to the importance of proper data for the accurate classification concerning computer-assisted Barrett's esophagus and adenocarcinoma detection.

Full digital workflow for crown lengthening by using a single surgical guide.

A technique using a digital workflow for performing crown lengthening by using a free software program is presented to digitally design a single surgical guide. The technique consists of obtaining standard tessellation language (STL) files from intraoral scans from a digital design of the new tooth shape and from a cone beam computed tomography (CBCT) scan, after which Digital Imaging and Communications in Medicine (DICOM) files are converted to the STL format. These files are then superimposed and used for surgical planning of the crown-lengthening procedure. The main component of the surgical guide is a labial upper band representing the biological width measurement based on the predicted digitally designed future gingival margin position. Accordingly, the lower edge of the band indicates the level of the main marginal incision, whereas the top of the band indicates the level where the alveolar bone crest must be repositioned by alveolotomy during the surgical crown-lengthening procedure. By performing an adequate diagnosis of the potential restorative outcome, the new position of the gingival margin and the crown shape can be predicted, and whether osteoplasty is needed can be determined.

Impact of different scanning strategies on the accuracy of two current intraoral scanning systems in complete-arch impressions: an in vitro study.

AIM: To determine the scanning strategy that obtains the most accurate results for two intraoral scanners (IOS) in complete-arch digital impressions. Scan time was evaluated and correlated with scan strategies. MATERIALS AND METHOD: A custom model used as the reference standard was fabricated with teeth having dentin- and enamel-identical refractive indices simulating natural dentition. A reference scan of the custom typodont was obtained using an ATOS III Triple Scan 3D optical scanner. Two IOS setups - Omnicam v 5.1.0 and Primescan v 5.0.2 - were used for complete-arch scanning, each using 13 scanning strategies, obtaining 260 digital files (n = 10 per group), recording each scan time, converting all experimental scans to standard tessellation language (STL) format, and using a comprehensive metrology program to compare the reference standard scan with the experimental scans. Statistical analyses utilized Welch's unequal variances t test. RESULTS: Group M exhibited the lowest trueness and precision values (P < 0.05) for Primescan (47.5% of the average among all other groups) and the lowest trueness value (P < 0.05) for Omnicam (53.4% of the average among all other groups), where group B exhibited the lowest precision value (65.6% of the average among all other groups) with P < 0.05. Primescan featured a better trueness index (4.79 µm) than that of Omnicam (19.13 µm), with a statistically significant difference (P < 0.00001). Primescan, group M, also featured a better precision index (4.67 µm) than Omnicam, group B (16.75 µm), with a statistically significant difference (P < 0.00001). CONCLUSION: For both IOS systems, group M provided the lowest scanning times. For trueness and precision of complete-arch scans, group M was the dominant scanning strategy in Primescan, while there was no dominant strategy in Omnicam. Group M had the best scanning time for both IOS systems.

Fracture Resistance of CAD/CAM Lithium Disilicate of Endodontically Treated Mandibular Damaged Molars Based on Different Preparation Designs.

The aim of this study was to evaluate the fracture resistance of 2 different types of all-ceramic crown using immediate dentin sealing (IDS), obtained using a CAD/CAM system on molars with different preparations. Forty extracted lower molars were endodontically treated and divided into four groups (n = 10) according to the dental preparation. Group 1 (SP0) was prepared without filling the pulp chamber and crown-root junction was located at the cementoenamel junction (CEJ). Group 2 (SP1) was prepared without filling the pulp chamber and crown-root junction was located 1-mm above the CEJ. Groups 3 and 4 contained a flat preparation surface with no axial wall height. Group 3 (CP0) was made IDS with complete filling of the pulp chamber with composite resin and crown-root junction was located at the CEJ. Group 4 (CP1) was prepared with complete filling of the pulp chamber and crown-root junction was located 1-mm above the CEJ. All groups were restored with CAD/CAM lithium disilicate ceramic crowns. Specimens were subjected to the fracture test and statistically analyzed using analysis of variance (ANOVA). Fracture mode was determined using a stereoscopic microscope, classified as repairable or nonrepairable, and analyzed using Fischer's exact test. Results indicated that there were no significant differences between the groups in terms of fracture resistance or fracture pattern (p >0.05). Fracture resistance was the lowest in the SP0 group, followed by the SP1 group (1634.38 N) of CP0 (1821.50 N), and it was the highest in the CP1 group. There was a predominance of nonrepairable fractures and there were no significant differences in the fracture resistance and fracture mode of CAD/CAM lithium disilicate molar all-ceramic crowns. Endodontically treated molars teeth might be restored with endocrowns or all-ceramic crowns on flat preparation; however tooth fracture failures that affect reliability of these types of restorations should be considered.

Effect of thickness, translucency, and firing protocol on the masking ability of a CAD/CAM zirconia-reinforced lithium silicate for different backgrounds.

PURPOSE: To evaluate the masking ability of computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia-reinforced lithium silicate (ZLS) glass-ceramic under the different material configurations of thickness, translucency, and finishing protocol as well as significance of the color difference due to the manufacturer's one-firing protocol. MATERIALS AND METHODS: Ninety high-translucency (HT) and low-translucency (LT) ZLS glass-ceramic discs of different thicknesses (1.0, 1.5, and 2.0 mm) were evaluated as a monolithic structure with and without the use of a one-firing protocol. Disc samples were placed onto the substrates for measurement; a spectrophotometer measured the L*, a*, and b* color attributes of each specimen. ∆E value was calculated for determining color differences in tooth-colored substrate specimens (shade B1) compared with three darker backgrounds (shade C2, and two metal substrates - gold and silver). ∆E values were then compared against clinically acceptable (∆E = 5.5) and ideal (∆E = 2.6) thresholds. Color differences between the control and test groups were evaluated under different effects using a series of one-sided paired t tests (P < 0.01). The 99% confidence interval (CI) for the true ∆E mean and P values are reported and discussed. A complementary regression analysis depicts the effect size of translucency and firing protocol. RESULTS: Over C2, a 1-mm thickness demonstrated P < 0.01 for the clinically acceptable threshold, whereas the ideal threshold was ensured only with P < 0.01 under a 2-mm thickness. Over silver, only the clinically acceptable standard was met with P < 0.01 under a 2-mm thickness. Over gold, a 1-mm thickness was clinically acceptable with P < 0.01, and the ideal standard was met with P < 0.01 under a 1.5-mm thickness. These results remained valid regardless of the firing protocol or translucency; however, significant (P < 0.01) yet small-sized effects were found for translucency and firing protocol over gold, and for translucency over silver, through multiple regression analysis. CONCLUSIONS: To achieve ideal masking, the minimum thickness of CAD/CAM ZLS glass-ceramic should be 1.5 mm over a gold background, and 2 mm over a C2 background. The silver background did not achieve ideal masking in any situation. The one-firing protocol did not affect the final color and can be used to increase restoration strength.

Fracture strength of CAD/CAM posterior ceramic crowns after manual enhancement of occlusal morphology.

PURPOSE: The aim of this study was to investigate the fracture strength of computer-aided design/computer-aided manufacturing (CAD/CAM) posterior ceramic crowns with and without post-milling manual enhancement of occlusal morphology (MEOM), as indicated especially with early CAD/CAM restorations that have limited capacity to generate natural occlusal morphology. MATERIALS AND METHODS: A mandibular molar of an acrylic tooth model was prepared to receive a CAD/CAM all-ceramic crown and was used as a master die to fabricate 80 prepared tooth replicas using an epoxy resin with an elastic modulus (E) of 18 GPa. The crown was designed using Cerec software's Biogeneric Copy Design mode (Sirona). Eighty identical monolithic crowns were fabricated by milling four types of ceramic blocks. Forty monolithic crowns (10 of each ceramic system) were randomly selected as the control group, and MEOM was performed for each of the other 40 crowns by a certified dental technician. Restorations were crystallized and glazed according to the manufacturers' instructions and firing protocols. All crowns were cemented to their respective die using resin cement, and loaded to fracture at a crosshead speed of 0.5 mm/min. The resultant fractures were classified into three modes. Data were statistically analyzed using the nonparametric Mann-Whitney U test at α = 0.05. RESULTS: The MEOM treatment decreased the fracture load for all ceramic brands. CONCLUSION: The MEOM procedure should be considered detrimental for monolithic CAD/CAM-generated crowns and should thus be avoided.

Fracture resistance of single-rooted pulpless teeth using hybrid CAD/CAM blocks for post and core restoration.

PURPOSE: The purpose of this study was to determine whether there is a significant difference in the fracture strengths of hybrid computer-aided design/computer-aided manufacturing (CAD/CAM) blocks and fiber posts for post and core restorations in both ferrule and nonferrule pulpless mandibular canines. MATERIALS AND METHOD: Forty extracted human mandibular canines were divided into ferrule and nonferrule groups and restored with hybrid CAD/CAM blocks using either the CAD/CAM system or fiber posts (control). Thus, there were four subgroups of ten specimens each. A 45-degree oblique load was applied with a crosshead of 0.5 mm/min, and the fracture loads were recorded. The mode of fracture was evaluated using an optical microscope at 3× magnification, and the data were tabulated and statistically analyzed using the Mann-Whitney U test and the t test, respectively, for the existence of significant difference at a 0.05 significance level. RESULTS: No statistically significant difference was found between the fracture strength under oblique loading when using hybrid CAD/CAM blocks and fiber posts in both ferrule and nonferrule groups. The failure mode distribution of the nonferrule group presented no unfavorable failures, whereas failures in the ferrule groups were spread out between the Favorable and Unfavorable groups. CONCLUSIONS: The results show that hybrid CAD/CAM blocks can be considered as an alternative restorative system in post and core restorations. Further basic and clinical research should be conducted to support the improvement of this system.

Ten-Year Follow-Up of a Fragment Reattachment to an Anterior Tooth: A Conservative Approach.

This report describes the 10-year follow-up data of a patient who underwent fragment reattachment to the maxillary central incisor after coronal fracture with pulp exposure as well as the procedures followed for functional and esthetic adjustments. A 9-year-old female patient presented at the clinic of dentistry at the State University of Rio de Janeiro with a coronal fracture and pulp exposure of the right maxillary central incisor that had occurred immediately after an accident. The intact tooth fragment was recovered at the accident site and stored in milk. The treatment plan followed was to perform direct pulp capping and tooth fragment reattachment. When the patient was 14 years old, adhesion between fragment and remaining tooth was lost, and fragment reattachment was performed. Five years later, the same tooth presented clinical discoloration and absence of sensitivity during pulp vitality tests. Subsequently, a new treatment plan was formulated, which included endodontic treatment, followed by nonvital tooth bleaching and light-cured composite resin restoration. An esthetic and natural-looking restoration was achieved. Tooth fragment reattachment is not a temporary restorative technique and requires functional and esthetic adjustments over time to maintain the biomimetic characteristics of traumatized anterior teeth and predictable outcomes.

Utilização de cerâmica híbrida CAD/CAM em restaurações posteriores com limitação de espaço interoclusal / Use of CAD/CAM hybrid ceramic in posterior restorations with interocclusal space limitation ­ case report

O objetivo deste relato de caso foi descrever o tratamento restaurador de elementos posteriores com limitação de espaço interoclusal, através de uma cerâmica híbrida CAD/CAM. Paciente do sexo masculino, com 54 anos de idade, foi reabilitado com restaurações monolíticas posteriores no hemiarco superior e inferior direito através de duas inlays, uma onlay, uma overlay, uma coroa total e uma coroa endodôntica adesiva, utilizando-se bloco de estrutura híbrida. Após diagnóstico, planejamento, procedimentos operatórios especiais, preparos dentários e afastamento gengival, a aquisição de imagens, o processamento de modelos e o desenho de restaurações foram executados em um sistema CAD/CAM chairside. As restaurações foram fabricadas em uma fresadora de quatro eixos, sendo submetidas a procedimentos de acabamento, polimento e cimentação adesiva. A cerâmica híbrida para CAD/CAM constituiu-se em um material adequado para a fabricação de restaurações posteriores, com ou sem limitação de espaço interoclusal. Durante o período de acompanhamento de 36 meses, não foram observadas patologias pulpares ou perirradiculares, além de função, ajuste marginal, forma anatômica e ausência de descolorações ou pigmentações nas restaurações. Confi rmados sucesso e estabilidade do procedimento restaurador, são necessários acompanhamentos clínicos de longa duração para corroboração de resultados, assim como investigação dos efeitos sobre a dentição antagônica.

The objective of this case report was to describe the restorative treatment of posterior elements with interocclusal space limitation through a CAD/CAM hybrid ceramic. A 54-year-old male patient was rehabilitated with posterior monolithic restorations in the upper and lower right arch through two inlays, one onlay, one overlay, one total crown and one adhesive endodontic crown using a hybrid framework block. After diagnosis, planning, adhesive procedures, dental preparations and gingival displacement, the image acquisition, model processing and restorations' design were performed in a "chairside" CAD/CAM system. The restorations were fabricated in a four-axis milling machine, finished, polished and adhesively cemented. Hybrid CAD/CAM ceramics was a suitable material for the manufacturing of posterior restorations with or without interocclusal space limitation. During the 36-month followup examination, no pulp or periradicular pathologies were observed, besides function, marginal adjustment, anatomical shape and absence of discoloration or pigmentation in restorations. Confirmed the success and restorative procedure stability, longterm clinical follow-ups are necessary to corroborate the results, as well as to investigate the effects on the opposite dentition.

Esthetic Rehabilitation through Crown Lengthening Surgery and Conservative CAD/CAM Veneers: A Multidisciplinary Case Report.

This case report describes a successful multidisciplinary approach used to improve the smile esthetics of a patient presenting with excessive gingival display, asymmetric gingival margins, and small upper anterior teeth and lower anterior teeth. The treatment combined esthetic crown lengthening, dental bleaching, and restorative dentistry using CAD/CAM veneer. The 6-month follow-up examination confirmed the stability of the modification and absence of adverse effects.