Challenges of computer-assisted orthognathic surgery in clinical application / 口腔疾病防治

@#After years of development, the advantages of computer-assisted orthognathic surgery have been widely recognized. However, the clinical application of this technology is challenging. Each step may generate errors from data acquisition, computer-assisted diagnosis, and computer-assisted surgical design, causing errors to be transferred from the virtual surgical plan to the operation. The accumulation and amplification of errors will affect the final surgical effect. Currently, digital devices, such as intraoral scanners, are being explored for error control, utilizing automation methods and algorithms, and implementing personalized bone positioning methods. Moreover, there are still many problems that have not been fully resolved, such as precise simulation of postoperative soft tissue, functional assessment of mandibular movement, and absorbable internal fixation materials. Fully understanding computer-assisted orthognathic surgery's limitations could provide direction for optimizing existing methods while helping clinicians avoid risks and maximize its advantages to achieve the best outcome. Many emerging and cutting-edge technologies, such as personalized titanium plates, artificial intelligence, and surgical robots, will further promote the development of this discipline. We can expect future optimization of digital orthognathic surgical technology by innovations in automation, intelligence, and personalization.

Performance analysis of pretrained convolutional neural network models for ophthalmological disease classification / Análise de desempenho de modelos de rede neural convolucional pré-treinados para classificação de doenças oftalmológicas

ABSTRACT Purpose: This study aimed to evaluate the classification performance of pretrained convolutional neural network models or architectures using fundus image dataset containing eight disease labels. Methods: A publicly available ocular disease intelligent recognition database has been used for the diagnosis of eight diseases. This ocular disease intelligent recognition database has a total of 10,000 fundus images from both eyes of 5,000 patients for the following eight diseases: healthy, diabetic retinopathy, glaucoma, cataract, age-related macular degeneration, hypertension, myopia, and others. Ocular disease classification performances were investigated by constructing three pretrained convolutional neural network architectures including VGG16, Inceptionv3, and ResNet50 models with adaptive moment optimizer. These models were implemented in Google Colab, which made the task straight-forward without spending hours installing the environment and supporting libraries. To evaluate the effectiveness of the models, the dataset was divided into 70%, 10%, and 20% for training, validation, and testing, respectively. For each classification, the training images were augmented to 10,000 fundus images. Results: ResNet50 achieved an accuracy of 97.1%; sensitivity, 78.5%; specificity, 98.5%; and precision, 79.7%, and had the best area under the curve and final score to classify cataract (area under the curve = 0.964, final score = 0.903). By contrast, VGG16 achieved an accuracy of 96.2%; sensitivity, 56.9%; specificity, 99.2%; precision, 84.1%; area under the curve, 0.949; and final score, 0.857. Conclusions: These results demonstrate the ability of the pretrained convolutional neural network architectures to identify ophthalmological diseases from fundus images. ResNet50 can be a good architecture to solve problems in disease detection and classification of glaucoma, cataract, hypertension, and myopia; Inceptionv3 for age-related macular degeneration, and other disease; and VGG16 for normal and diabetic retinopathy.

RESUMO Objetivo: Avaliar o desempenho de classificação de modelos ou arquiteturas de rede neural convolucional pré--treinadas usando um conjunto de dados de imagem de fundo de olho contendo oito rótulos de doenças diferentes. Métodos: Neste artigo, o conjunto de dados de reconhecimento inteligente de doenças oculares publicamente disponível foi usado para o diagnóstico de oito rótulos de doenças diferentes. O banco de dados de reconhecimento inteligente de doenças oculares tem um total de 10.000 imagens de fundo de olho de ambos os olhos de 5.000 pacientes para oito categorias que contêm rótulos saudáveis, retinopatia diabética, glaucoma, catarata, degeneração macular relacionada à idade, hipertensão, miopia, outros. Investigamos o desempenho da classificação de doenças oculares construindo três arquiteturas de rede neural convolucional pré-treinadas diferentes, incluindo os modelos VGG16, Inceptionv3 e ResNet50 com otimizador de Momento Adaptativo. Esses modelos foram implementados no Google Colab o que facilitou a tarefa sem gastar horas instalando o ambiente e suportando bibliotecas. Para avaliar a eficácia dos modelos, o conjunto de dados é dividido em 70% para treinamento, 10% para validação e os 20% restantes utilizados para teste. As imagens de treinamento foram expandidas para 10.000 imagens de fundo de olho para cada tal. Resultados: Observou-se que o modelo ResNet50 alcançou acurácia de 97,1%, sensibilidade de 78,5%, especificidade de 98,5% e precisão de 79,7% e teve a melhor área sob a curva e pontuação final para classificar a categoria da catarata (área sob a curva=0,964, final=0,903). Em contraste, o modelo VGG16 alcançou uma precisão de 96,2%, sensibilidade de 56,9%, especificidade de 99,2% e precisão de 84,1%, área sob a curva 0,949 e pontuação final de 0,857. Conclusão: Esses resultados demonstram a capacidade das arquiteturas de rede neural convolucional pré-treinadas em identificar doenças oftalmológicas a partir de imagens de fundo de olho. ResNet50 pode ser uma boa solução para resolver problemas na detecção e classificação de doenças como glaucoma, catarata, hipertensão e miopia; Inceptionv3 para degeneração macular relacionada à idade e outras doenças; e VGG16 para retinopatia normal e diabética.

Effect of the COVID-19 pandemic on cataract surgery by residents who had routine surgical simulator training during residency

ABSTRACT Purpose: To assess the effect of the coronavirus disease 2019 (COVID-19) pandemic on cataract surgery by residents who had mandatory surgical simulator training during residency. Methods: In this retrospective, observational analytical study, the total number of cataract surgeries and surgical complications by all senior residents of 2019 (2019 class; prepandemic) and 2020 (2020 class; affected by the reduced number of elective surgeries due to the COVID-19 pandemic) were collected and compared. All residents had routine mandatory cataract surgery training on a virtual surgical simulator during residency. The total score obtained by these residents on cataract challenges of the surgical simulator was also evaluated. Results: The 2020 and 2019 classes performed 1275 and 2561 cataract surgeries, respectively. This revealed a reduction of 50.2% in the total number of procedures performed by the 2020 class because of the pandemic. The incidence of surgical complications was not statistically different between the two groups (4.2% in the 2019 class and 4.9% in the 2020 class; p=0.314). Both groups also did not differ in their mean scores on the simulator's cataract challenges (p<0.696). Conclusion: Despite the reduction of 50.2% in the total number of cataract surgeries performed by senior residents of 2020 during the COVID-19 pandemic, the incidence of surgical complications did not increase. This suggests that surgical simulator training during residency mitigated the negative effects of the reduced surgical volume during the pandemic.

Digital analysis of unilateral ptosis repair: external levator advancement vs. Müller's muscle conjunctival resection

ABSTRACT Purpose: Evaluation of lid contour and marginal peak point changes to compare outcomes of external levator advancement and Müller's muscle conjunctival resection surgery in unilateral ptosis. Methods: We reviewed the charts of unilateral ptosis patients who underwent external levator advancement or Müller's muscle conjunctival resection. Eyelid contour analysis was conducted on preoperative and 6-month postoperative digital images. This was performed with the multiple margin reflex distances technique, measuring the vertical distance from a line intersecting the center of the pupil to the eyelid margin at 10 positions at 2 mm intervals. The marginal peak point changes were analyzed digitally using the coordinates of the peak point according to the pupil center. Each position's mean distance was compared preoperatively, postoperatively, and with the fellow eyelid. Results: Sixteen patients underwent external levator advancement and 16 patients had Müller's muscle conjunctival resection. The mean margin reflex distance was improved by both techniques (1.46 vs. 2.43 mm and 1.12 vs. 2.25 mm, p=0.008 and p=0.0001 respectively) and approached that of the fellow eyelid (2.43 vs. 2.88 and 2.25 vs. 2.58 mm, p=0.23 and p=0.19, respectively). However, statistically significant lid margin elevation was limited to between the N6 and T6 points in the external levator advancement group. Whereas, significant elevation was achieved along the whole lid margin in the Müller's muscle conjunctival resection group. The marginal peak point was shifted slightly laterally in the external levator advancement group (p=0.11). Conclusions: Both techniques provide effective lid elevation, however, the external levator advancement's effect lessens toward the canthi while Müller's muscle conjunctival resection provides more uniform elevation across the lid margin. The margin reflex distance alone is not sufficient to reflect contour changes.

Development of a convolutional neural network for diagnosing osteoarthritis, trained with knee radiographs from the ELSA-Brasil Musculoskeletal / Desenvolvimento de rede neural convolucional para o diagnóstico radiográfico de osteoartrite dos joelhos no ELSA-Brasil Musculoesquelético

Abstract Objective: To develop a convolutional neural network (CNN) model, trained with the Brazilian "Estudo Longitudinal de Saúde do Adulto Musculoesquelético" (ELSA-Brasil MSK, Longitudinal Study of Adult Health, Musculoskeletal) baseline radiographic examinations, for the automated classification of knee osteoarthritis. Materials and Methods: This was a cross-sectional study carried out with 5,660 baseline posteroanterior knee radiographs from the ELSA-Brasil MSK database (5,660 baseline posteroanterior knee radiographs). The examinations were interpreted by a radiologist with specific training, and the calibration was as established previously. Results: The CNN presented an area under the receiver operating characteristic curve of 0.866 (95% CI: 0.842-0.882). The model can be optimized to achieve, not simultaneously, maximum values of 0.907 for accuracy, 0.938 for sensitivity, and 0.994 for specificity. Conclusion: The proposed CNN can be used as a screening tool, reducing the total number of examinations evaluated by the radiologists of the study, and as a double-reading tool, contributing to the reduction of possible interpretation errors.

Resumo Objetivo: Desenvolver um modelo computacional - rede neural convolucional (RNC) - treinado com radiografias da linha de base do Estudo Longitudinal de Saúde do Adulto Musculoesquelético (ELSA-Brasil Musculoesquelético), para a classificação automática de osteoartrite dos joelhos. Materiais e Métodos: Trata-se de um estudo transversal abrangendo todos os exames da linha de base do ELSA-Brasil Musculoesquelético (5.660 radiografias dos joelhos em incidência posteroanterior). Os exames foram interpretados por médico radiologista com treinamento específico e calibração previamente publicada. Resultados: A RNC desenvolvida apresentou área sob a curva característica de operação do receptor de 0,866 (IC 95%: 0,842-0,882). O modelo pode ser calibrado para alcançar, não simultaneamente, valores máximos de 0,907 para acurácia, 0,938 para sensibilidade e 0,994 para especificidade. Conclusão: A RNC desenvolvida pode ser utilizada como ferramenta de triagem, reduzindo o número total de exames avaliados pelos radiologistas do estudo, e/ou como ferramenta de segunda leitura, contribuindo com a redução de possíveis erros de interpretação.

Cirugía virtual guiada para rehabilitación implantosoportada de maxilar edéntulo con carga inmediata / Virtual guided surgery for implantsupported rehabilitation of the edentulous maxilla with immediate loading

Objetivo: Presentar el relato de un caso clínico de cirugía virtual guiada para rehabilitación implantosoportada de maxilar edéntulo con carga inmediata. Relato del caso: Paciente, edéntulo total en ambos maxilares, expresó su deseo de cambiar la prótesis total superior removible por una prótesis total fija sobre implantes. Durante la evaluación clínica, se observaron condiciones biológicas favorables al tratamiento como, adecuada faja de tejido queratinizado y leve reabsorción ósea. Como tratamiento se le sugiere al paciente, una planificación inversa, asistida por cirugía virtual guiada, utilizando un prototipo de guía quirúrgica para la colocación de seis implantes dentales en el maxilar y la instalación de una prótesis protocolo de carga inmediata. Conclusiones: Los resultados nos permiten concluir que la cirugía virtual guiada por computadora para rehabilitación protésica implantosoportada de maxilar edéntulo, con carga inmediata, proporciona precisión en los procedimientos quirúrgicos, es fundamental para la confección de prótesis inmediatas, representa una alternativa mínimamente invasiva y el resultado complace a los pacientes.

Objective: present the report of a clinical case of a virtual guided surgery for implant-supported rehabilitation of the edentulous maxilla with immediate loading. Case report: Patient, bi-maxillary edentulous expressed the desire to replace the removable upper total prothesis for a total fixed prothesis on implants. During the clinical evaluation, favorable biological conditions for treatment were observed, such as adequate keratinized tissue band and mild bone resorption. As part of the treatment, the patient was recommended a reverse planning approach, assisted by virtual guided surgery. This involved a prototype surgical guide for the fixation of six dental implants in the maxilla and the installation of an immediate loading protocol prosthesis. Conclusions: The results lead us to conclude that computer-guided virtual surgery for implant-supported prosthetic rehabilitation of the edentulous maxilla with immediate loading, provides a high precision in surgical procedures. It is essential to fabrication of immediate prostheses, represents a minimally invasive alternative, and results in patient satisfaction.

Transition to online teaching during COVID-19 pandemic: Perspective of higher education teachers from India

Objectives: This cross-sectional, anonymous and questionnaire-based study was undertaken to analyse online teaching experiences during COVID-19 lockdown in higher education from teachers’ perspectives. This was thought to help in improving long-distance education. Materials and Methods: An online survey was conducted to collect both quantitative and qualitative data from higher education teachers. Results: Benefits identified by online teachers indicate that distance education can cater to a large group and helps the students to access educational resources. Major challenges faced were internet connectivity (78.80%), increased workloads (68.80%) and lack of personal communication with students (84%). They believed that the online mode of teaching is the only alternative for students in such an extraordinary situation. It can be valuable for additional discussions but cannot replace traditional offline teaching. Conclusion: Suggestions pointed toward providing internet facilities and electronic databases to students and the necessity of faculty development programmes.

Validation of automated image co-registration integrated into in-house software for voxel-based internal dosimetry on single-photon emission computed tomography images / Validação do corregistro automático de imagem integrado a software de análise de dosimetria interna baseada em voxel para tomografia computadorizada de emissão de fóton único

Abstract Objective: To develop an automated co-registration system and test its performance, with and without a fiducial marker, on single-photon emission computed tomography (SPECT) images. Materials and Methods: Three SPECT/CT scans were acquired for each rotation of a Jaszczak phantom (to 0°, 5°, and 10° in relation to the bed axis), with and without a fiducial marker. Two rigid co-registration software packages-SPM12 and NMDose-coreg-were employed, and the percent root mean square error (%RMSE) was calculated in order to assess the quality of the co-registrations. Uniformity, contrast, and resolution were measured before and after co-registration. The NMDose-coreg software was employed to calculate the renal doses in 12 patients treated with 177Lu-DOTATATE, and we compared those with the values obtained with the Organ Level INternal Dose Assessment for EXponential Modeling (OLINDA/EXM) software. Results: The use of a fiducial marker had no significant effect on the quality of co-registration on SPECT images, as measured by %RMSE (p = 0.40). After co-registration, uniformity, contrast, and resolution did not differ between the images acquired with fiducial markers and those acquired without. Preliminary clinical application showed mean total processing times of 9 ± 3 min/patient for NMDose-coreg and 64 ± 10 min/patient for OLINDA/EXM, with a strong correlation between the two, despite the lower renal doses obtained with NMDose-coreg. Conclusion: The use of NMDose-coreg allows fast co-registration of SPECT images, with no loss of uniformity, contrast, or resolution. The use of a fiducial marker does not appear to increase the accuracy of co-registration on phantoms.

Resumo Objetivo: Desenvolver corregistro automático e testar seu desempenho com ou sem marcador fiducial em imagens de tomografia computadorizada de emissão de fóton único (SPECT). Materiais e Métodos: Três SPECT/CTs foram adquiridas para cada rotação de um simulador de Jaszczak em relação ao eixo da maca (0°, 5° e 10°), com e sem fiducial. Dois métodos de corregistro inelástico foram aplicados - SPM12 e NMDose-coreg -, e a porcentagem do erro quadrático médio (%RMSE) foi usada para analisar a qualidade do corregistro. Uniformidade, contraste e resolução foram medidos antes e após o corregistro. NMDose com corregistro automático foi usado para calcular a dose renal de 12 pacientes tratados com 177Lu-DOTATATE e comparado com OLINDA/EXM. Resultados: A marcação fiducial não modificou a qualidade do corregistro das imagens SPECT, medida pela %RMSE (p = 0,40). Não houve impacto na uniformidade, contraste e resolução após o corregistro de imagens adquiridas com ou sem fiduciais. Aplicação clínica preliminar mostrou tempo total de processamento de 9 ± 3 min/paciente para NMDose e 64 ± 10 min/paciente para OLINDA/EXM, com alta correlação entre ambos, apesar de menor dose renal em NMDose. Conclusão: NMDose-coreg permite o corregistro rápido de imagens SPECT, sem perda de uniformidade, contraste ou resolução. O uso da marcação fiducial não aumentou a precisão do corregistro em fantomas.

Protocolo Abreviado Guiado Digital: Técnicas de Marcadores Tisulares, Silicona de Registro y CBCT con Sonrisa / Digitally Guided Abbreviated Protocol: Tissue Marker Techniques, Recording Silicone and CBCT with Smile

Establecer un protocolo de cirugía guiada estática con técnicas referenciales para ser realizado de manera predecible, repetible y simple, en todos los tipos de casos. El protocolo abreviado guiado digital para cirugía guiada estática para implantes se centra en diseñar computacionalmente una guía quirúrgica que se apoye en el tejido remanente del paciente, siendo un protocolo digital versátil para la cirugía y rehabilitación implanto protésica, basada en registros clínicos, principalmente la línea de la sonrisa y la captación de ésta en tomografía de haz cónico (CBCT), además de establecer dimensión vertical oclusal (DVO). Logrando así, planificación de implantes hasta la inserción inmediata de la prótesis temporal. Se ejemplifica el trabajo con 2 casos clínicos. Se establece un protocolo con la intención de que pueda ser realizado en pacientes desdentados parciales (Técnica de Registro Silicona) o totales (Técnica de Marcadores Tisulares en prótesis), definiendo un flujo de trabajo tridimensional, digital y optimizado, con un consecuente ahorro de tiempo clínico. Como principio del protocolo de cirugía guiada es lograr el objetivo quirúrgico - protésico deseado con alta precisión. La cirugía y rehabilitación de implantes de manera convencional es altamente dependiente del operador por lo que la alternativa de cirugía guiada de manera estática es una herramienta más para mejorar el pronóstico del paciente. Se establece un protocolo digital simple y efectivo, de cirugía guiada, para la rehabilitación implanto protésica basada en la línea de la sonrisa, tomografía de haz cónico (CBCT), dimensión vertical oclusal (DVO). Protocolo predecible y que optimiza los tiempos clínicos, logrando una rehabilitación protésica inmediata acorde e individualizada para cada paciente.

Establish a static guided surgery protocol with referential techniques to be performed in a predictable, repeatable and simple way, in all types of cases. The abbreviated digital guided protocol for static guided surgery for implants focuses on computationally designing a surgical guide that rests on the patient's remaining tissue, being a versatile digital protocol for prosthetic implant surgery and rehabilitation, based on clinical records, mainly the line of the smile and its uptake in cone beam tomography (CBCT), in addition to establishing occlusal vertical dimension (OVD). Thus achieving implant planning until the immediate insertion of the temporary prosthesis. The work is exemplified with 2 clinical cases. A protocol is established with the intention that it can be carried out in partially edentulous patients (Silicone Registration Technique) or total (Tissue Marker Technique in prostheses), defining a three-dimensional, digital and optimized workflow, with a consequent saving of time. clinical. As a principle of the guided surgery protocol, it is to achieve the desired surgical-prosthetic objective with high precision. Conventional implant surgery and rehabilitation is highly dependent on the operator, so the alternative of statically guided surgery is one more tool to improve the patient's prognosis. A simple and effective digital protocol for guided surgery is established for prosthetic implant rehabilitation based on the smile line, cone beam tomography (CBCT), and occlusal vertical dimension (OVD). Predictable protocol that optimizes clinical times, achieving an immediate and individualized prosthetic rehabilitation for each patient.

Medição automática de valva mitral a partir de ecocardiograma utilizando processamento digital de imagens / Automatic measurement of the mitral valve based on echocardiography using digital image processing

Fundamento: A avaliação da área valvar mitral por meio da reconstrução multiplano na ecocardiografia tridimensional é restrita a softwares específicos e à experiência dos ecocardiografistas. Eles precisam selecionar manualmente o frame do vídeo que contenha a área de abertura máxima da valva mitral, dimensão fundamental para a identificação de estenose mitral. Objetivo: Automatizar o processo de determinação da área de abertura máxima da valva mitral, por meio da aplicação de Processamento Digital de Imagens (PDI) em exames de ecocardiograma, desenvolvendo um algoritmo aberto com leitura de vídeo no formato avi. Método: Este estudo piloto observacional transversal foi realizado com vinte e cinco exames diferentes de ecocardiograma, sendo quinze com abertura normal e dez com estenose mitral reumática. Todos os exames foram realizados e disponibilizados por dois especialistas, com autorização do Comitê de Ética em Pesquisa, que utilizaram dois modelos de aparelhos ecocardiográficos: Vivid E95 (GE Healthcare) e Epiq 7 (Philips), com sondas multiplanares transesofágicas. Todos os vídeos em formato avi foram submetidos ao PDI através da técnica de segmentação de imagens. Resultados: As medidas obtidas manualmente por ecocardiografistas experientes e os valores calculados pelo sistema desenvolvido foram comparados utilizando o diagrama de Bland-Altman. Observou-se maior concordância entre valores no intervalo de 0,4 a 2,7 cm². Conclusão: Foi possível determinar automaticamente a área de máxima abertura das valvas mitrais, tanto para os casos advindos da GE quanto da Philips, utilizando apenas um vídeo como dado de entrada. O algoritmo demonstrou economizar tempo nas medições quando comparado com a mensuração habitual. (AU)

Background: The evaluation of mitral valve area through multiplanar reconstruction in 3-dimensional echocardiography is restricted to specific software and to the experience of echocardiographers. They need to manually select the video frame that contains the maximum mitral valve opening area, as this dimension is fundamental to identification of mitral stenosis. Objective: To automate the process of determining the maximum mitral valve opening area, through the application of digital image processing (DIP) in echocardiography tests, developing an open algorithm with video reading in avi format. Method: This cross-sectional observational pilot study was conducted with 25 different echocardiography exams, 15 with normal aperture and 10 with rheumatic mitral stenosis. With the authorization of the Research Ethics Committee, all exams were performed and made available by 2 specialists who used 2 models of echocardiographic devices: Vivid E95 (GE Healthcare) and Epiq 7 (Philips), with multiplanar transesophageal probes. All videos in avi format were submitted to DIP using the image segmentation technique. Results: The measurements obtained manually by experienced echocardiographers and the values calculated by the developed system were compared using a Bland-Altman diagram. There was greater agreement between values in the range from 0.4 to 2.7 cm². Conclusion: It was possible to automatically determine the maximum mitral valve opening area, for cases from both GE and Philips, using only 1 video as input data. The algorithm has been demonstrated to save time on measurements when compared to the usual method. (AU)

Aplicación de la dinámica de sistemas en el análisis de la evolución de la hipoacusia y la evaluación del impacto de estrategias sanitarias

Objetivos: Aplicar la dinámica de sistemas para estimar la evolución de la incidencia y la prevalencia de hipoacusia en personas mayores en países de bajos, medios y altos ingresos, así como el acceso al tratamiento, y evaluar la influencia de la implementación de estrategias sanitarias sobre estos indicadores. Metodología: Los análisis se realizaron mediante simulación con dinámica de sistemas según parámetros globales. Para ello, se desarrolló un diagrama de bucles causal, integrando la incidencia, la prevalencia y el tratamiento de hipoacusia con el nivel de desigualdad, factores de riesgo, uso de dispositivos de ayuda auditiva, fuerza laboral de audiólogos y otorrinolaringólogos según el nivel de ingresos del país. Luego, se construyó un diagrama de flujo para ejecutar las simulaciones durante un período de 100 años. Además, se ejecutaron cuatro simulaciones con estrategias sanitarias (reducción de factores de riesgo, mejora en el uso dispositivos de ayuda auditiva, aumento del número de audiólogos y otorrinolaringólogos) y se estimó el porcentaje de cambio respecto al modelo basal. Resultados: Los países de bajos ingresos mostraron una mayor incidencia y prevalencia de hipoacusia, menor acceso a tratamiento adecuado y una mayor prevalencia de hipoacusia sin tratar o con tratamiento inadecuado. La reducción de factores de riesgo creció en un 15 y 33 % la población con audición normal en los próximos 50 y 100 años, respectivamente. Además, la mejora en el uso de dispositivos de ayuda auditiva logró una reducción del 60 % de la población con tratamientos inadecuados o sin tratamiento, y el aumento de audiólogos y otorrinolaringólogos incrementó un 250 % el acceso a un tratamiento adecuado. Conclusiones: La evolución de la salud auditiva está condicionada por factores económicos, donde los entornos más desfavorecidos muestran peores indicadores. Además, la implementación de estrategias combinadas favorecería la salud auditiva en el futuro.

Objectives: To estimate the evolution of the incidence and prevalence of hearing loss in the elderly in low-, middle- and high-income countries by means of system dynamics simulation according to global parameters and to analyze the influence of the implementation of health strategies. Methodology: A causal loop diagram was developed to relate the incidence, prevalence and treatment of hearing loss to the level of inequality, risk factors (RF), use of hearing aids (HA), audiologist and otolaryngologist (ENT) workforce by country income level. A flow chart was then constructed to run the simulations over a 100-year period. In addition, four simulations were run with health strategies (reduction of RF, improvement in HA use, increase in the number of audiologists and ENT specialists) and the percentage change from the baseline model was estimated. Results: Low-income countries showed a higher incidence and prevalence of hearing loss, less access to adequate treatment, and a higher prevalence of untreated or inadequately treated hearing loss. The reduction of RF increased the population with normal hearing by 15% and 33% over the next 50 and 100 years, respectively. In addition, the improvement in the use of ha achieved a 60% reduction in the population with inadequate or untreated treatment, and the increase in audiologists and ENT specialists improved the access to adequate treatment by 250%. Conclusions: The evolution of hearing health is conditioned by economic factors, where the most disadvantaged environments show worse indicators. In addition, the implementation of combined strategies would favor hearing health in the future. System dynamics is a very useful methodology for health managers because it enables to understand how a disease evolves and define what are the best health interventions considering different scenarios.

Objetivos: Aplicar a dinâmica do sistema para estimar a evolução da incidência e prevalência da perda auditiva em pessoas idosas em países de baixo, médio e alto rendimento, bem como o acesso ao tratamento, e avaliar a influência da implementação de estratégias de saúde sobre estes indicadores. Metodologia: As análises foram conduzidas utilizando simulação da dinâmica do sistema com base em parâmetros globais. Para tal, foi desenvolvido um diagrama do laço causal, integrando a incidência, prevalência e tratamento da perda auditiva com o nível de desigualdade, fatores de risco, utilização de aparelhos auditivos, mão-de-obra de audiologistas e otorrinolaringologistas por nível de rendimento nacional. Foi então construído um fluxograma para executar as simulações ao longo de um período de 100 anos. Além disso, foram realizadas quatro simulações com estratégias de saúde (reduzindo os fatores de risco, melhorando a utilização de aparelhos auditivos, aumentando o número de audiologistas e otorrinolaringologistas) e foi estimada a mudança percentual em relação ao modelo de base. Resultados: Os países de baixos rendimentos mostraram maior incidência e prevalência de perda auditiva, menor acesso a tratamento apropriado e maior prevalência de perda auditiva não tratada ou tratada de forma inadequada. A redução dos fatores de risco aumentou a população com audição normal em 15 e 33% durante os próximos 50 e 100 anos, respectivamente. Além disso, uma melhor utilização de aparelhos auditivos permitiu uma redução de 60% na população mal tratada ou não tratada, e o aumento do número de audiologistas e especialistas em ORL aumentou em 250% o acesso ao tratamento adequado. Conclusões: A evolução da saúde auditiva é condicionada por fatores económicos, com os ambientes mais desfavorecidos a apresentarem indicadores piores. Além disso, a implementação de estratégias combinadas favoreceria a saúde auditiva no futuro.

Implementation of the online learning management system ‘Moodle’ as a blended approach to online teaching

Objectives: Web-based learning is becoming a newly accepted standard in education, more so with COVID-19 pandemic. To use technology to redesign learning experiences, a blend of synchronous and asynchronous approaches was used wherein the routine lectures through MS Teams (synchronous) were integrated with an online learning management system (LMS), ‘Moodle’ (modular object-oriented dynamic learning environment) based, four-quadrant approach (asynchronous). We aimed to determine the student’s engagement, performance and perception of the new online LMS. Materials and Methods: All 170 students of the 1st year MBBS of batch 2020 were enrolled in the course. A module was developed for teaching ‘Physiology of Vision’ with this blended approach. Along with routine online lectures through Microsoft Teams, supplementary materials in the form of multimedia presentations and additional links to useful websites were provided through online LMS. The online activity of students was recorded and assessments were done. A feedback form was filled out by students at the end of the course. Results: A significant positive correlation of examination scores with individual student’s activity logs and significantly better scores in top Moodle users along with significantly higher marks in Moodle-based modules than in other modules confirmed the value of Moodle in improving student performance. Overall feedback from students was clearly in favour of implementing Moodle as a complementary tool to traditional teaching. Conclusion: Moodle improved the quality of learning. It developed interest and motivation among students and has a positive impact on academic outcomes.

Satisfaction levels of students toward online teaching and assessment in a medical college in North India during COVID-19 related lockdown

Background: Medical colleges had to adopt online teaching methods after the imposition of worldwide lockdown due to COVID related pandemic. It is important to understand satisfaction levels among medical students regarding online teaching, to improve online teaching methods in future. Aim and Objectives: The present study aimed to evaluate the satisfaction levels among medical students with regard to online teaching and assessment program and factors associated with low satisfaction levels. Materials and Methods: An observational cross-sectional survey was conducted on 600 MBBS students. Various online teaching methods were implemented April 2020 onward. This survey was sent to the students in July 2020. Satisfaction levels toward various online teaching and assessments were evaluated using a five point Likert scale. Results: A total of 446 MBBS students responded to our survey. We found 1st year of MBBS curriculum (adjusted odds ratio [AOR] = 2.55, P < 0.05), teachers’ inability to explain theory concepts (AOR = 2.47, P < 0.01), teachers not keeping the class interactive (AOR = 1.81, P < 0.01), student unable to hear the teacher adequately (AOR = 1.77, P < 0.01), student being inattentive in class (AOR = 2.06, P < 0.01), and non-availability of high speed internet connectivity (AOR = 1.85, P < 0.001) to be significantly associated with students not being overall satisfied with online teaching. Conclusion: Online platforms proved to be relevant for teaching theory but usefulness for clinical or practical education was not found to be adequate.

Mucin levels in glands of the colonic mucosa of rats with diversion colitis subjected to enemas containing sucralfate and n-acetylcysteine alone or in combination

ABSTRACT Purpose: To evaluate the tissue content of neutral and acidic mucins, sulfomucins and sialomucins in colonic glands devoid of intestinal transit after enemas containing sucralfate and n-acetylcysteine alone or in combination. Methods: Sixty-four rats underwent intestinal transit bypass. A colonic segment was collected to compose the white group (without intervention). After derivation, the animals were divided into two groups according to whether enemas were performed daily for two or four weeks. Each group was subdivided into four subgroups according to the substance used: control group: saline 0.9%; sucralfate group (SCF): SCF 2 g/kg/day; n-acetylcysteine group (NAC): NAC 100 mg/kg/day; and SCF+NAC group: SCF 2 g/kg/day + NAC 100 mg/kg/day.Neutral and acidic mucins were stained by periodic acid-Schiff and alcian-blue techniques, respectively. The distinction between sulfomucins and sialomucin was made by the high alcian-blue iron diamine technique. The content of mucins in the colonic glands was measured by computerized morphometry. The inflammatory score was assessed using a validated scale. The results between the groups were compared by the Mann-Whitney's test, while the variation according to time by the Kruskal-Wallis' test (Dunn's post-test). A significance level of 5% was adopted. Results: There was reduction in the inflammatory score regardless of the application of isolated or associated substances. Intervention with SCF+NAC increased the content of all mucin subtypes regardless of intervention time. Conclusions: The application of SCF+NAC reduced the inflammatory process of the colonic mucosa and increased the content of different types of mucins in the colonic glands of segments excluded from fecal transit.

Application of computer-assisted navigation technology in the resection and reconstruction of mandibular ameloblastoma / 口腔医学

Objective@# Using computer-assisted navigation technology to guide the resection and reconstruction of mandibular ameloblastoma, evaluating its treatment effect.@*Methods @# Twelve patients were selected from the Affiliated Stomatological Hospital of Nanjing University from January 2017 to May 2022. All 12 patients accepted same surgery which included resection of mandibular ameloblastoma and reconstruction by fibula musculocutaneous flap. Among them, 6 cases were included in the navigation group; 6 cases were in the non-navigation group. Advantages and disadvantages of computer-assisted navigation technology in this operation were evaluated with these cases. @*Results@# The 12 operations were performed by the same operator. The average time for fixing the navigation bracket and performing navigation in the navigation group was about 15 minutes. Compared with the non-navigation group, the average operation time in the navigation group was shortened by about 10 minutes. In the navigation group, the mandible resection range matched the fibula musculocutaneous flap well, and the occlusal relationship recovered well. @*Conclusion @#Using the mandibular reference frame, under the guidance of computer-assisted navigation technology, the resection and reconstruction of mandibular ameloblastoma can be performed quickly and accurately.

Application of Trados software in the English translation of Chinese patent medicine instructions / 中国药房

OBJECTIVE To standardize the English translations of the current Chinese patent medicine （CPM） instructions in order to increase its English translation quality and improve its readability. METHODS In an attempt to standardize its English translation， 64 CPM instructions were collected as samples for translation projects in Trados， using its two core functions of translation memory and terminology， combined with pre-editing （PRE） and post-editing （PE） skills. RESULTS The results showed that translation projects had up to 21.65% perfect match. Based on translation project practice， it is proposed to use the free translation or transcreation plus transliteration method to translate product names of CPM， and apply two human-computer interaction translation modes：“ machine translation （MT）+computer-assisted translation （CAT）+PE” and “PRE+MT+CAT+PE”， which are adopted in the translation of weak literary sections and strong literary sections， respectively. CONCLUSIONS The application of CAT not only improves the translation quality and the translation mode， reduces the translation cost， and maintains the consistency and style of the translation， but also accumulates language assets for future use， providing a novel reference for translating traditional Chinese medicine literature.

Intelligent diagnostic model of keratoconus based on deep learning algorithm / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To establish an intelligent diagnostic model of keratoconus for small-diameter corneas by data mining and analysis of patients' clinical data.METHODS: Diagnostic study. A total of 830 patients(830 eyes)were collected, including 338 male(338 eyes)and 492 female(492 eyes), with an average age of 14-36(23.19±5.71)years. Among them, 731 patients(731 eyes)had undergone corneal refractive surgery at Chongqing Nanping Aier Eye Hospital from January 2020 to March 2022, and 99 patients had a diagnosed keratoconus from January 2015 to March 2022. Corneal diameter ≤11.1 mm was measured by Pentacam in all patients. Two cornea specialists classified patients' data into normal corneas, suspect keratoconus, and keratoconus groups based on the Belin/Ambrósio enhanced ectasia display(BAD)system in Pentacam. The data of 665 patients were randomly selected as the training set and the other 165 patients as the validation set by computer random sampling method. Seven parametric corneal features were extracted by convolutional neural networks(CNN), and the models were built by Residual Network(ResNet), Vision Transformer(ViT), and CNN+Transformer, respectively. The diagnostic accuracy of models was verified by cross-entropy loss and cross-validation method. In addition, sensitivity and specificity were evaluated using receiver operating characteristic curve.RESULTS: The accuracy of ResNet, ViT, and CNN+Transfermer for the diagnosis of normal cornea and suspect keratoconus was 85.57%, 86.11%, and 86.54% respectively, and the area under the receiver operating characteristic curve(AUC)was 0.823, 0.830 and 0.842 respectively. The accuracy of models for the diagnosis of suspect keratoconus and keratoconus was 97.22%, 95.83%, and 98.61%, respectively, and the AUC was 0.951, 0.939, and 0.988 respectively.CONCLUSION: For corneas ≤11.1 mm in diameter, the data model established by CNN+Transformer has a high accuracy rate for classifying keratoconus, which provides real and effective guidance for early screening.

Application of deep learning to the differenciation of the invasion depth in colorectal adenomas / 中华消化内镜杂志

Objective:To evaluate deep learning for differentiating invasion depth of colorectal adenomas under image enhanced endoscopy (IEE).Methods:A total of 13 246 IEE images from 3 714 lesions acquired from November 2016 to June 2021 were retrospectively collected in Renmin Hospital of Wuhan University, Shenzhen Hospital of Southern Medical University and the First Hospital of Yichang to construct a deep learning model to differentiate submucosal deep invasion and non-submucosal deep invasion lesions of colorectal adenomas. The performance of the deep learning model was validated in an independent test and an external test. The full test was used to compare the diagnostic performance between 5 endoscopists and the deep learning model. A total of 35 videos were collected from January to June 2021 in Renmin Hospital of Wuhan University to validate the diagnostic performance of the endoscopists with the assistance of deep learning model.Results:The accuracy and Youden index of the deep learning model in image test set were 93.08% (821/882) and 0.86, which were better than those of endoscopists [the highest were 91.72% (809/882) and 0.78]. In video test set, the accuracy and Youden index of the model were 97.14% (34/35) and 0.94. With the assistance of the model, the accuracy of endoscopists was significantly improved [the highest was 97.14% (34/35)].Conclusion:The deep learning model obtained in this study could identify submucosal lesions with deep invasion accurately for colorectal adenomas, and could improve the diagnostic accuracy of endoscopists.

Comparison of effects of absolute scatter correction and relative scatter correction on image quality in PET reconstruction / 中华核医学与分子影像杂志

Objective:To study the impact of different scattering correction algorithms in the reconstruction of PET/CT images on image artifacts and the precision of quantitative parameters.Methods:The phantom as described in the National Electrical Manufacturers Association (NEMA) NU2 standard was filled with 18F. The background activity was fixed, and the activity of the solution in the spheres was adjusted to obtain several configurations, including the normal ratio group (4.08∶1) and the extreme ratio group (200∶1). The surface contamination group with the same ratio as the extreme ratio group contained a small radioactive source with different doses of 18F (74, 37, 3.7 and 0.37 MBq) placed at the surface of the phantom. PET/CT images of 30 patients (21 males, 9 females, age: (44.5±10.2) years) from Peking University Cancer Hospital & Institute between July 2012 and December 2021 were retrospectively analyzed, including 10 with normal images ( 18F-FDG) and 20 with abnormal images (10 with dislocation during acquisition, 10 with surface contamination). The images were reconstructed with relative and absolute scattering correction. The phantom was evaluated using the target to background ratio (TBR) and the artifact classification. CV as well as the artifact classification were used to compare the clinical image quality. Mann-Whitney U test and χ2 test were used to analyze data. Results:In the normal ratio group and the extreme ratio group, the TBRs of phantom images reconstructed with relative correction were significantly higher than those with absolute correction (normal ratio group: 3.30(1.94, 4.53) vs 2.72(1.56, 3.56); z=-2.20, P=0.028; extreme ratio group: 105.47(45.62, 162.82) vs 101.36(43.96, 155.57); z=-1.99, P=0.046). In the surface contamination group, with the increase of the activity of the small source, the artifact became more obvious, and the artifact classification score of absolute correction was significantly better than that of relative correction (1.5(1.0, 2.0) vs 2.5(2.0, 3.0); z=-2.00, P=0.046). In the 10 normal 18F-FDG PET/CT patients, the CVliver of the relative correction (9.67%(8.00%, 11.00%)) was significantly lower than that of absolute correction (11.00%(9.00%, 12.00%); z=-2.57, P=0.010), indicating the higher image quality of images with relative correction. In abnormal images, the image quality of absolute correction was significantly higher than that of relative correction with fewer and less severe artifacts (dislocation cases: 9/10 vs 4/10; χ2=5.50, P=0.019; surface contamination cases: 9/10 vs 4/10; χ2=5.50, P=0.019). Conclusions:The relative scattering correction is suitable for normal situations in clinical PET acquisition. However, with dislocation or surface contamination, the absolute scattering correction helps to reduce the artifacts and improve the image quality.

Analysis of values and differences of multi-modality registration and normalization methods in 18F-AV45 PET imaging for Alzheimer′s disease / 中华核医学与分子影像杂志

Objective:To explore values and differences of multi-modality image registration and normalization methods in 18F-AV45 PET quantitative analysis of Alzheimer′s disease (AD). Methods:Twenty AD patients (10 males, 10 females; age (77.0±5.8) years) and 20 normal controls (NC; 8 males, 12 females; age (75.2±4.8) years) from the AD neuroimaging initiative (ADNI) open database of the National Institute on Aging were analyzed. β-amyloid (Aβ) deposition (positive/negative) was assessed by visual analysis. The SUV ratio (SUVr) in each brain region and individual average SUVr were calculated using template normalization method (M1), normalization after registration with 18F-FDG PET or MRI image (M2 or M3) respectively with the cerebellum as the reference area. The intra-class correlation coefficient (ICC) was used to complete the reliability between methods, and independent-sample t test and one-way repeated measures analysis of variance were used to compare the differences of quantitative indexes between different groups and different methods. ROC curve analysis was used to compare the diagnostic efficacy in distinguishing AD and NC, Aβ positive and negative cases. Results:There were 15 and 6 patients with positive Aβ deposition in AD group and in NC group respectively by visual analysis. The SUVrs of three methods were with good consistency (ICC=0.82, P<0.001), and the differences among individual average SUVrs (1.29±0.17, 1.36±0.23, 1.45±0.24) were significant ( F=68.78, P<0.001). There were significant differences between AD group (1.39±0.17, 1.48±0.24, 1.58±0.25) and NC group (1.20±0.10, 1.24±0.15, 1.33±0.16; t values: 3.55-4.33, all P<0.05), Aβ positive group (1.39±0.16, 1.50±0.21, 1.59±0.23) and negative group (1.19±0.11, 1.21±0.14, 1.31±0.15; t values: 4.58, 5.11, 4.41, all P<0.001), and the individual average SUVr of M3 was higher (both P<0.001). The AUCs of distinguishing Aβ positive and negative deposition of M1-M3 were 0.86, 0.88, 0.84 and the thresholds of SUVrs were 1.29, 1.37, 1.52, respectively. Conclusion:The three multi-modality registration and normalization methods are reliable methods for quantitation of 18F-AV45 PET imaging with certain differences, and should be selected carefully based on data conditions in practice.