Precisão dos escaneamentos intraorais e modelos 3D, com diferentes escâneres e softwares: revisão sistemática / Accuracy of intraoral scanning and 3D models, with different scanners and software: systematic review

Objetivo: Esta revisão sistemática investigou se a precisão dos escaneamentos intraorais e modelos 3D com diferentes escâneres e softwares, é suficiente para os clínicos aceitarem e implementarem as novas tecnologias como critério de diagnóstico e planejamentos dos tratamentos. Material e métodos: Protocolo PROSPERO número CRD42020218151. Duas revisoras realizaram uma pesquisa avançada de banco de dados eletrônico, sem restrição de idioma ou data, no MEDLINE/PubMed; Embase; BVS/LILACS; Scopus; Cochrane Library; Google Scholar e Web of Science até janeiro de 2021. Os estudos foram escolhidos por título e resumo para triagem, de acordo com os seguintes critérios de inclusão: Estudos Clínicos in vivo e in vitro (pacientes, modelos de gesso de pacientes e manequins simulando bocas humanas) com os diferentes softwares e técnicas de escaneamento intraoral comparando a acurácia, fidelidade e/ou precisão como desfecho dos escaneamentos intraorais, dos modelos virtuais em 3D com modelos de gesso; com um mínimo de 5 pacientes escaneados sem limite de idade ou gênero; texto completo acessível; nos estudos de coorte, transversais e caso-controle. Após a leitura do texto completo os artigos foram excluídos de acordo com os seguintes critérios: 1) estudos com menos de 5 pacientes; 2) estudos em animais; 3) revisão sistemática, descrição de técnica, intervenções, protocolos; 4) escaneamentos por Ressonância Magnética ou Tomografia computadorizada; 5) estudos em que não foram utilizados scanners intraorais. Resultados. Dos 4410 estudos inicialmente identificados, 16 preencheram os critérios de inclusão. O guia PRISMA foi utilizado para redação da revisão e a ferramenta ROBINS-1 da Cochrane foi utilizada para análise de viés. Os estudos incluídos na sua maioria mostraram diferenças estatisticamente significativas entre os resultados das moldagens convencionais e digitais, porém também demonstraram que as diferenças não têm significância clínica. Conclusões: Esta revisão sistemática permitiu levantar dados que demonstraram que os escaneamentos intraorais não são superiores às moldagens convencionais, mas de acurácia equivalente com confiabilidade para o uso das imagens digitais conseguidas por escaneamento intraoral e dos modelos digitais provenientes destes escaneamentos.

Determinação do sexo a partir da morfometria geométrica e mensurações em imagens tridimensionais de dentes caninos / Sex determination from geometric morphometry and measurements in three-dimensional images of canine teeth

O presente estudo teve como objetivo avaliar a determinação do sexo por meio da análise geométrica e de mensurações a partir de imagens tridimensionais de dentes caninos, advindas de escaneamento intraoral, no Autodesk MeshMixer, bem como elaborar um roteiro prático para servir de guia na manipulação e coleta de dados nesse software. Trata-se de um estudo do tipo cego e transversal, dividido em duas etapas. Inicialmente, foram selecionadas imagens de 127 caninos (65 femininos e 63 masculinos) para a análise morfométrica geométrica, utilizando a marcação de 50 pontos, distribuídos em 27 pontos para contorno e 23 pontos para delimitação da forma das superfícies vestibular e lingual. Cada ponto de referência recebeu um valor para as coordenadas x, y e z, representando a sua posição. Na análise estatística dos dados foi utilizado um software específico para análise morfométrica geométrica, o MorphoJ, no qual foram importados os dados e submetidos à Análise Ajustada de Procrustes, Análise Discriminante e Análise da Variação Canônica. Não foram exibidas diferenças significativas para distribuição do sexo nas analises anteriores. Ainda, os dados relativos ao tamanho do centroide gerado no MorphoJ foram importados para o IBM SPSS Statistics 22.0 e submetidos ao teste t student, resultando em uma diferença estatística para o sexo. Para a aplicabilidade das mensurações digitais, foram utilizadas imagens de 345 caninos (191 femininos e 154 masculinos). Foram realizadas medidas das distâncias mesiodistais, vestibulolinguais, cervicoincisais (altura) e distâncias intercaninas de 5 pontos estabelecidos em cada canino (cúspide, cervical por vestibular e lingual, ponto máximo mesial e lingual). Todas as médias foram maiores para o sexo masculino e, com exceção da altura do elemento 33, apresentaram diferenças significativas para o sexo (p<0,05). As mensurações mesiodistais, vestibulolinguais e intercaninas (com exceção do ponto cervical por lingual), apresentaram uma boa acurácia, representadas por valores de áreas sobre a curva ROC maiores do que 0,7. O Autodesk MeshMixer apresentou-se como um ótimo auxiliar e de grande contribuição para análises dentro da Antropologia Forense. Apesar dos caninos serem elementos altamente dimórficos, para a análise morfométrica, não foram exibidas diferenças estatísticas na análise discriminante. Porém, o tamanho do centroide apresentou diferenças estatísticas e com médias maiores para o sexo masculino. As medidas realizadas nos dentes caninos apresentaram diferenças estatísticas para o sexo, com boas classificações na análise discriminante e com boas predições sexuais de acordo com os valores de especificidade e sensibilidade. A aplicabilidade de técnicas digitais de mensuração exibiu bons resultados, concordando esses dados obtidos com estudos que utilizaram as técnicas manuais de medida.

Necesidad de aprendizaje del médico general sobre Imagenología durante la COVID-19 para su formación laboral / The General Practitioner's Need for Learning Imaginology during COVID-19

Para afrontar la reciente emergencia global por COVID-19, la comunidad científica y los profesionales de la salud en Cuba trabajan constantemente en el desarrollo de nuevos tratamientos y tecnologías que posibiliten el diagnóstico precoz de esta enfermedad, todo ello para facilitar el manejo general de esta pandemia.1) De ahí que se requiere el perfeccionamiento continuo de este proceso en correspondencia con los principios de la medicina, con una formación humanista, científica y con una visión integral de los problemas de salud como elemento esencial que caracteriza la formación de profesionales de la salud en territorio cubano donde la especialidad de Medicina General Integral constituye la principal disciplina integradora de contenidos, para ofrecer una atención preventiva, sistemática y continua al paciente a lo largo del tiempo, donde el médico en formación sea expresión de sus cualidades humanas. Coherente con esto, en 1984 se inició en Cuba la formación de especialistas en Medicina General Integral (MGI). Esta especialidad no tenía antecedentes en el país, por lo cual su propuesta constituye el perfeccionamiento del enfoque social de la medicina, que desde su implantación es la premisa básica del sistema de salud cubano. La formación de estos profesionales ocurre en la propia comunidad, con una alta calidad en los servicios que se brindan a la población.2 Para cumplir con esta función...(AU)

Explaining Skeletal System Anatomy with Classical Method, Video Assisted Method and 3D Imaging Techniques and Comparison of Learning Levels Between Methods

SUMMARY: The aim of this research is to introduce the ideal lecture technique to the literature by explaining the anatomy of the skeletal system using the classical method, video-assisted method and 3D imaging techniques. The research was carried out with 180 students. The number of samples was determined by power analysis (a=0.05,b=0.20, effect size=0.25). Participants were pre-screened and divided into 4 groups with the closest group mean (group 1: control group: the group that did not take anatomy lessons, group 2: video-assisted anatomy education, group 3: 3D anatomy course, group 4: classical anatomy education group). The courses in the training groups were organised as 4 hours/day, 2 days/week for 5 weeks. At the end of the course, the students were re-examined and scaled to determine the difference in scores and self-efficacy between the groups. A one-way ANOVA test was performed because the data were normally distributed when comparing between groups. The mean scores were calculated as group 1=30.22±6.24, group 2=39.02±9.15, group 3=49.77±9.20 and group 4=59.28±8.95. In the post hoc comparison, in pairwise comparisons between all groups, the differences were highly significant (pgroup 3>group 2>group 1 (p<0.001). According to the results of this study, the laboratory method in skeletal anatomy teaching is the best alternative to 3D anatomy teaching.

El objetivo de esta investigación es introducir la técnica de lectura ideal en la literatura, explicando la anatomía del sistema esquelético, utilizando el método clásico, el método asistido por video y las técnicas de imágenes en 3D. La investigación se llevó a cabo con 180 estudiantes. El número de muestras se determinó mediante análisis de potencia (a=0,05, b=0,20, tamaño del efecto=0,25). Los participantes fueron preseleccionados y divididos en 4 grupos con la media de grupo más cercana (grupo 1: grupo de control: el grupo que no tomó lecciones de anatomía, grupo 2: educación de anatomía asistida por video, grupo 3: curso de anatomía 3D, grupo 4: grupo de educación en anatomía clásica). Los cursos en los grupos de formación se organizaron con 4 horas/día, 2 días/semana durante 5 semanas. Al final del curso, los estudiantes fueron reexaminados y escalados para determinar la diferencia en puntajes y autoeficacia entre los grupos. Se realizó una prueba de ANOVA de una vía debido a que los datos se distribuyeron normalmente al comparar entre grupos. Las puntuaciones medias se calcularon como grupo 1=30,22±6,24, grupo 2=39,02±9,15, grupo 3=49,77±9,20 y grupo 4=59,28±8,95. En la comparación post hoc, en comparaciones por pares entre todos los grupos, las diferencias fueron altamente significativas (pgrupo 3>grupo 2>grupo 1 (p<0,001). Según los resultados de este estudio, el método de laboratorio en la enseñanza de la anatomía esquelética es la mejor alternativa a la enseñanza de la anatomía en 3D.

Benefícios do planejamento digital para cirurgias periodontais estéticas: relato de caso / Benefits of digital planning for esthetic periodontal surgeries: case report

Sorriso gengival é comumente conhecido pela exposição excessiva das gengivas ao sorrir, acarretando assim na diminuição das coroas dos elementos. No que tange a etiologia dessa condição, ela se apresenta de maneiras diversas e sua identificação é fundamental para o desenvolvimento de um plano de tratamento eficaz. O planejamento clínico pode ser feito usando uma abordagem dinâmica e digital do sorriso, como softwares, exames de imagem, modelos virtuais 3D e guias cirúrgicos, melhorando a qualidade e precisão do tratamento, oferecendo diversos benefícios aos pacientes. Sendo assim esse estudo teve como objetivo demonstrar a importância dos processos digitais no planejamento e correção do sorriso gengival. Paciente queixou-se da desproporção do sorriso, caracterizado por coroas curtas nas regiões de pré-molares e incisivos ligadamente com a exposição excessiva da gengiva ao sorrir. Após estudos clínicos e de imagem, a etiologia foi diagnosticada como erupção passiva alterada, tipo I (fenótipo espesso). O tratamento de escolha foi o remodelamento gengival associado à osteotomia e osteoplastia obtendo assim uma maior precisão no tratamento, sendo confeccionado um guia cirúrgico duplo. Sendo assim, é possível contemplar que o planejamento digital permite uma maior previsibilidade da execução, compatibilidade em relação a expectativa do paciente e profissional, além da total individualização do caso, tornando os resultados mais favoráveis e exatos e minimizando as chances de iatrogenias(AU)

Gummy smile is commonly known for exposing the gums to the smile, thereby increasing the crowns elevation of the elements. Regarding a condition, it presents itself in different ways and its identification is fundamental for the development of a treatment plan. The clinician can be done using a dynamic and digital approach to image treatment, such as software, imaging exams, various 3D virtual models and elaborate guides, improving the quality and precision of treatment, offering benefits to patients. Therefore, this study aimed to demonstrate the importance of digital processes in planning and correcting the gummy smile. Patient complained of disproportion of the smile, facing the regions of premolar crowns and incisors of the smile, facing the exposure of the gingiva when smiling. After clinical and imaging exams, the diagnostic studies were diagnosed as passive eruption, type I (phenotype and specific). The choice of choice was remodeling associated with surgery treatment and surgery treatment, thus providing a greater precision in the treatment, being a double guide elaborated. Therefore, it is possible that the digital is possible a predictability of execution, compatibility in relation to patient and professional care, in addition to the greater possibility of individualization planning than it allows, making the results more planned as possibilities and exactly the iatrogenic(AU)

The Automation of Breast Ultrasonography and the Medical Time Dedicated to the Method / A automatização da ultrassonografia mamária e o tempo médico dedicado ao método

Abstract In this integrative review, we aimed to describe the records of time devoted by physicians to breast ultrasound in a review of articles in the literature, in order to observe whether the automation of the method enabled a reduction in these values. We selected articles from the Latin American and Caribbean Literature in Health Sciences (LILACS) and MEDLINE databases, through Virtual Health Library (BVS), SciELO (Scientific Electronic Library Online), PubMed, and Scopus. We obtained 561 articles, and, after excluding duplicates and screening procedures, 9 were selected, whose main information related to the guiding question of the research was synthesized and analyzed. It was concluded that the automation of breast ultrasound represents a possible strategy for optimization of the medical time dedicated to the method, but this needs to be better evaluated in comparative studies between both methods (traditional and automated), with methodology directed to the specific investigation of this potentiality.

Resumo Na presente revisão integrativa, objetivamos descrever os registros de tempo dedicado pelos médicos à ultrassonografia mamária em revisão de artigos da literatura, visando observar se a automação do método possibilitou redução destes valores. Selecionamos artigos nas bases de dados Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e MEDLINE, através da Biblioteca Virtual em Saúde (BVS), Scientific Electronic Library Online (SciELO), PubMed e Scopus. Obtivemos 561 artigos e, após a exclusão de artigos duplicados e procedimentos de triagem, foram selecionados 9 artigos, cujas informações principais relativas à pergunta norteadora da pesquisa foram sintetizadas e analisadas. Foi concluído que a automação da ultrassonografia mamária representa uma possível estratégia de otimização do tempo médico dedicado ao método; porém, essa conclusão necessita ser melhor avaliada em estudos comparativos entre ambos os métodos (tradicional e automatizado), com metodologia direcionada à investigação específica desta potencialidade.

A Morphometric Study of Head in the Population of Young Chinese Adults / Estudio Morfométrico de la Cabeza en la Población de Adultos Jóvenes Chinos

SUMMARY: Due to the complexity of head shape, limited 1D or 2D head anthropometry fail to fully capture its shape characteristics. Currently, there is limited research on clustering analysis of head shape from a shape difference perspective, especially for the head shape of Chinese people. Head shape is influenced by factors such as race, sex, and age, making it imperative to create a head shape database for Chinese individuals. In this study, three-dimensional head data of 339 Chinese young adult were collected, and the head shapes were clustered into 7 clusters using an improved k-medoids algorithm. The differences between clusters and the average head shape were further analyzed. It can be foreseen that the head shape database for Chinese young adult constructed in this study has important reference value for the ergonomic design of head-related products and head morphology research, among other fields.

Debido a la complejidad de la forma de la cabeza, la antropometría limitada de ésta, en 1D o 2D, no logra capturar completamente sus características de forma. Actualmente, existen estudios limitados sobre el análisis de agrupamiento de la forma de la cabeza, desde una perspectiva de diferencia de forma, especialmente en el caso de la población china. La forma de la cabeza está influenciada por factores como la raza, el sexo y la edad, por lo que resulta imperativo crear una base de datos sobre la forma de la cabeza de los individuos chinos. En este estudio, se recopilaron datos tridimensionales de la cabeza de 339 adultos jóvenes chinos, y las formas de la cabeza se agruparon en 7 grupos utilizando un algoritmo k-medoids mejorado. Las diferencias entre los grupos y la forma promedio de la cabeza se analizaron a profundidad. Se puede prever que la base de datos sobre la forma de la cabeza de adultos jóvenes chinos construida en este estudio, tiene un valor de referencia importante para el diseño ergonómico de productos relacionados con la morfología de la cabeza, entre otros campos.

Radiological morphometric study of the hyoid bone using three-dimensional computed tomography (3D-CT) scans / Estudio morfométrico radiológico del hueso hioides mediante tomografía computarizada tridimensional (3D-CT)

SUMMARY: Hyoid bone measurements have been proposed to vary between different genders and age groups. The aim of the study is to study hyoid morphometrics among Jordanian patients. 3D-CT scans of 637 patients were analyzed. Ten parameters of hyoid bone were measures, including the anteroposterior length, length of greater horns (right and left), height of greater horns (right and left), width of hyoid body, height of hyoid body, the distance between the midpoints of the posterior ends of the greater horns of the hyoid bone, the angle between right and left greater horns, and the distance of the hyoid bone to the vertebral column. Also, vertebral level, fusion rank, morphology of hyoid body lingula, and shape of hyoid bone were documented. All hyoid dimensions were longer in males, but greater horns angle was wider in females. In patients younger than 30 years, the parameters are the smallest with the widest angle. The distance from hyoid to vertebral column is higher in males (30-49) years of age. No fusion between hyoid body and greater horns was observed in patients younger than 10 years, but fusion (unilateral or bilateral) was found in only 73.2 % of patients ≥ 70 years. The hyoid was mostly at vertebra C3 level and "U" shaped. The lingula shape was mostly "Scar" in males (especially ≥ 50 years) and "Nothing" in females (especially < 50 years). The maximum growth of hyoid dimensions is before age of 30 years. Fusion between hyoid body and greater horns was not seen in patients younger than 10 years. Otherwise, the hyoid features failed to predict age or gender in our sample. Furthermore, 3D-CT scan is an excellent tool to assess the anatomy of head and neck region.

Se ha propuesto que las medidas del hueso hioides varían entre los diferentes sexos y grupos de edad. El objetivo del estudio fur estudiar la morfometría del hueso hioides en pacientes jordanos. Se analizaron tomografías computarizadas en 3D de 637 pacientes. Se midieron diez parámetros del hueso hioides, incluyendo la longitud anteroposterior, la longitud de los cuernos mayores (derecho e izquierdo), la altura de los cuernos mayores (derecho e izquierdo), el ancho del cuerpo hioides, la altura del cuerpo hioides, la distancia entre los puntos medios de los extremos posteriores de los cuernos mayores del hueso hioides, el ángulo entre los cuernos mayores derecho e izquierdo, y la distancia del hueso hioides a la columna vertebral. Además, se documentaron el nivel vertebral, el rango de fusión, la morfología de la língula del cuerpo hioides y la forma del hueso hioides. Todas las dimensiones del hioides fueron más largas en los hombres, pero el mayor ángulo de los cuernos fue más ancho en las mujeres. En pacientes menores de 30 años, los parámetros son los más pequeños con el ángulo más amplio. La distancia del hioides a la columna vertebral es mayor en el sexo masculino (30-49) años. No se observó fusión entre el cuerpo hioides y los cuernos mayores en pacientes menores de 10 años, pero se encontró fusión (unilateral o bilateral) en solo el 73,2 % de los pacientes ≥ 70 años. El hioides estaba mayormente al nivel de la vértebra C3 y en forma de "U". La forma de la língula era mayoritariamente "Cicatriz" en los hombres (especialmente ≥ 50 años) y "Nada" en las mujeres (especialmente < 50 años). El máximo crecimiento de las dimensiones del hioides es antes de los 30 años. La fusión entre el cuerpo hioides y los cuernos mayores no se observó en pacientes menores de 10 años. No obstante, las características del hueso hioides no pudieron predecir la edad o el sexo en nuestra muestra. Además, la tomografía computarizada 3D es una herramienta excelente para evaluar la anatomía de la región de la cabeza y el cuello.

Sex Estimation of Han Adults in Western China Based on Three-Dimensional Cranial CT Reconstruction / 法医学杂志

OBJECTIVES@#To examine the reliability and accuracy of Walker's model for estimating the sex of Han adults in western China by using cranium three-dimensional (3D) CT reconstruction, and to study the suitable cranial sex estimation model for Han people in western China.@*METHODS@#A total of 576 cranial CT 3D reconstructed images from Hanzhong Hospital in Shaanxi Province from 2017 to 2021 were collected. These images were divided into the experimental group with 486 samples and the validation group with 90 samples. Walker's model was used by observer 1 to estimate the sex of experimental group samples. The logistic function applicable to Han people in western China was corrected by observer 1. The 90 samples in the validation group were scored and substituted into the modified logistic function to complete the back substitution test by observer 1, 2 and 3.@*RESULTS@#The accuracy of sex estimation of Han adults in western China was 63.2%-77.2% by applying Walker's model. The accuracy of modified logistic function was 82.9%. The accuracy of sex estimation through back substitution test by 3 observers was 75.6%-91.1%, with a Kappa value of 0.689 (P<0.05) for inter-observer consistency and 0.874 (P<0.05) for intra-observer consistency.@*CONCLUSIONS@#There are great differences in bone characteristics among people from different regions. The modified logistic function can achieve higher accuracy in Han adults in western China.

Preliminary evaluation of the trueness of 5 chairside 3D facial scanning techniques / 北京大学学报(医学版)

OBJECTIVE@#To quantitatively evaluate the trueness of five chairside three-dimensional facial scanning techniques, and to provide reference for the application of oral clinical diagnosis and treatment.@*METHODS@#The three-dimensional facial data of the subjects were collected by the traditional professional three-dimensional facial scanner Face Scan, which was used as the reference data of this study. Four kinds of portable three-dimensional facial scanners (including Space Spider, LEO, EVA and DS-FScan) and iPhone Ⅹ mobile phone (Bellus3D facial scanning APP) were used to collect three-dimensional facial data from the subjects. In Geomagic Studio 2013 software, through data registration, deviation analysis and other functions, the overall three-dimensional deviation and facial partition three-dimensional deviation of the above five chairside three-dimensional facial scanning technologies were calculated, and their trueness performance evaluated. Scanning time was recorded during the scanning process, and the subject's comfort was scored by visual analogue scale(VAS). The scanning efficiency and patient acceptance of the five three-dimensional facial scanning techniques were evaluated.@*RESULTS@#DS-FScan had the smallest mean overall and mean partition three-dimensional deviation between the test data and the reference data, which were 0.334 mm and 0.329 mm, respectively. The iPhone Ⅹ mobile phone had the largest mean overall and mean partition three-dimensional deviation between the test data and the reference data, which were 0.483 mm and 0.497 mm, respectively. The detailed features of the three-dimensional facial data obtained by Space Spider were the best. The iPhone Ⅹ mobile phone had the highest scanning efficiency and the highest acceptance by the subject. The average scanning time of the iPhone Ⅹ mobile phone was 14 s, and the VAS score of the subjects' scanning comfort was 9 points.@*CONCLUSION@#Among the five chairside three-dimensional face scanning technologies, the trueness of the scan data of the four portable devices had no significant difference, and they were all better than the iPhone Ⅹ mobile phone scan. The subject with the iPhone Ⅹ scanning technology had the best expe-rience.

Current application and limitations of augmented reality in the stomatology / 中华口腔医学杂志

Computer-assisted technology are gradually integrated into dental education and clinical treatment. As a cutting-edge technology in computer-aided medicine, augmented reality can not only be used as an aid to dental education by presenting three-dimensional scenes for teaching demonstration and experimental skills training, but also can superimpose virtual image information of patients onto real lesion areas for real-time feedback and intraoperative navigation. This review explores the current applications and limitations of augmented reality in dentistry to provide a reference for future research.

Study on the method of automatically determining maxillary complex landmarks based on non-rigid registration algorithms / 中华口腔医学杂志

Objective: To explore an automatic landmarking method for anatomical landmarks in the three-dimensional (3D) data of the maxillary complex and preliminarily evaluate its reproducibility and accuracy. Methods: From June 2021 to December 2022, spiral CT data of 31 patients with relatively normal craniofacial morphology were selected from those who visited the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology. The sample included 15 males and 16 females, with the age of (33.3±8.3) years. The maxillary complex was reconstructed in 3D using Mimics software, and the resulting 3D data of the maxillary complex was mesh-refined using Geomagic software. Two attending physicians and one associate chief physician manually landmarked the 31 maxillary complex datasets, determining 24 anatomical landmarks. The average values of the three expert landmarking results were used as the expert-defined landmarks. One case that conformed to the average 3D morphological characteristics of healthy individuals' craniofacial bones was selected as the template data, while the remaining 30 cases were used as target data. The open-source MeshMonk program (a non-rigid registration algorithm) was used to perform an initial alignment of the template and target data based on 4 landmarks (nasion, left and right zygomatic arch prominence, and anterior nasal spine). The template data was then deformed to the shape of the target data using a non-rigid registration algorithm, resulting in the deformed template data. Based on the unchanged index property of homonymous landmarks before and after deformation of the template data, the coordinates of each landmark in the deformed template data were automatically retrieved as the automatic landmarking coordinates of the homonymous landmarks in the target data, thus completing the automatic landmarking process. The automatic landmarking process for the 30 target data was repeated three times. The root-mean-square distance (RMSD) of the dense corresponding point pairs (approximately 25 000 pairs) between the deformed template data and the target data was calculated as the deformation error of the non-rigid registration algorithm, and the intra-class correlation coefficient (ICC) of the deformation error in the three repetitions was analyzed. The linear distances between the automatic landmarking results and the expert-defined landmarks for the 24 anatomical landmarks were calculated as the automatic landmarking errors, and the ICC values of the 3D coordinates in the three automatic landmarking repetitions were analyzed. Results: The average three-dimensional deviation (RMSD) between the deformed template data and the corresponding target data for the 30 cases was (0.70±0.09) mm, with an ICC value of 1.00 for the deformation error in the three repetitions of the non-rigid registration algorithm. The average automatic landmarking error for the 24 anatomical landmarks was (1.86±0.30) mm, with the smallest error at the anterior nasal spine (0.65±0.24) mm and the largest error at the left oribital (3.27±2.28) mm. The ICC values for the 3D coordinates in the three automatic landmarking repetitions were all 1.00. Conclusions: This study established an automatic landmarking method for three-dimensional data of the maxillary complex based on a non-rigid registration algorithm. The accuracy and repeatability of this method for landmarking normal maxillary complex 3D data were relatively good.

Advances in algorithms for three-dimensional craniomaxillofacial features construction based on point clouds / 中华口腔医学杂志

In light of the increasing digitalization of dentistry, the automatic determination of three-dimensional (3D) craniomaxillofacial features has become a development trend. 3D craniomaxillofacial landmarks and symmetry reference plane determination algorithm based on point clouds has attracted a lot of attention, for point clouds are the basis for virtual surgery design and facial asymmetry analysis, which play a key role in craniomaxillofacial surgery and orthodontic treatment design. Based on the studies of our team and national and international literatures, this article presented the deep geometry learning algorithm to determine landmarks and symmetry reference plane based on 3D craniomaxillofacial point clouds. In order to provide reference for future clinical application, we describe the development and latest research in this field, and analyze and discuss the advantages and limitations of various methods.

Automatic determination of mandibular landmarks based on three-dimensional mandibular average model / 北京大学学报(医学版)

OBJECTIVE@#To explore an efficient and automatic method for determining the anatomical landmarks of three-dimensional(3D) mandibular data, and to preliminarily evaluate the performance of the method.@*METHODS@#The CT data of 40 patients with normal craniofacial morphology were collected (among them, 30 cases were used to establish the 3D mandibular average model, and 10 cases were used as test datasets to validate the performance of this method in determining the mandibular landmarks), and the 3D mandibular data were reconstructed in Mimics software. Among the 40 cases of mandibular data after the 3D reconstruction, 30 cases that were more similar to the mean value of Chinese mandibular features were selected, and the size of the mandibular data of 30 cases was normalized based on the Procrustes analysis algorithm in MATLAB software. Then, in the Geomagic Wrap software, the 3D mandibular average shape model of the above 30 mandibular data was constructed. Through symmetry processing, curvature sampling, index marking and other processing procedures, a 3D mandible structured template with 18 996 semi-landmarks and 19 indexed mandibular anatomical landmarks were constructed. The open source non-rigid registration algorithm program Meshmonk was used to match the 3D mandible template constructed above with the tested patient's 3D mandible data through non-rigid deformation, and 19 anatomical landmark positions of the patient's 3D mandible data were obtained. The accuracy of the research method was evaluated by comparing the distance error of the landmarks manually marked by stomatological experts with the landmarks marked by the method of this research.@*RESULTS@#The method of this study was applied to the data of 10 patients with normal mandibular morphology. The average distance error of 19 landmarks was 1.42 mm, of which the minimum errors were the apex of the coracoid process [right: (1.01±0.44) mm; left: (0.56±0.14) mm] and maximum errors were the anterior edge of the lowest point of anterior ramus [right: (2.52±0.95) mm; left: (2.57±1.10) mm], the average distance error of the midline landmarks was (1.15±0.60) mm, and the average distance error of the bilateral landmarks was (1.51±0.67) mm.@*CONCLUSION@#The automatic determination method of 3D mandibular anatomical landmarks based on 3D mandibular average shape model and non-rigid registration algorithm established in this study can effectively improve the efficiency of automatic labeling of 3D mandibular data features. The automatic determination of anatomical landmarks can basically meet the needs of oral clinical applications, and the labeling effect of deformed mandible data needs to be further tested.

Radiographic diagnosis of distal fibula avulsion fractures: Comparison of ankle X-ray and three-dimensional reconstruction of CT / 北京大学学报(医学版)

OBJECTIVE@#To investigate the difference in sensitivity between X-ray and three-dimensional reconstruction of computed tomography (3D-CT) for the diagnosis of distal fibular avulsion fracture, and the radiographic presentation of the ossicle.@*METHODS@#From January to October 2018, 92 patients with distal fibular avulsion fracture were visited for surgical treatment in Department of Sports Medicine, Peking University Third Hospital, and 60 cases were finally enrolled according to the inclusion and exclusion criteria. Intraoperative detection was regarded as the gold standard, and the diagnostic sensitivity of preoperative ankle X-ray and 3D-CT for the distal fibular avulsion fractures was statistically determined. The ossicle maximum diameter as well as the degree of its displacement were also measured. On 3D-CT, the distance from the ossicle center point to the anterior fibular tuberosity (a), the distance to the fibular tip (b), and the a/b value was used to present the ossicle displacement.@*RESULTS@#Among the 60 patients, 36 and the 52 patients were correctly detected by X-ray and 3D-CT, respectively, and the sensitivities was 60.0% and 86.7%, respectively (P=0.004). The mean diameter of the ossicle on X-ray and 3D-CT was (9.2±3.9) mm and (10.5±3.2) mm, respectively. The mean distance from the ossicle center to the anterior fibular tuberosity (a) was (17.5±3.6) mm and the mean distance to the fibular tip (b) was (17.4±4.8) mm, with mean a/b values of 1.1±0.7. The intraclass correlation coefficients (ICC) for each measurement ranged from 0.891-0.998 with a high degree of consistency.@*CONCLUSION@#Compared with X-ray, 3D-CT has higher sensitivity in diagnosing distal fibular avulsion fractures, can help clinicians evaluate ossicle's location and choose surgical methods, and is recommended to be performed in patients with suspected distal fibula avulsion fractures in clinical practice.

A prevalence survey of cone-beam computed tomography use among endodontic practitioners / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinical application of cone-beam computed tomography (CBCT) among endodontic practitioners, and to analyze the indications and reasonability of CBCT in the diagnosis and treatment of pulpal and periapical diseases.@*METHODS@#The clinical data were collected from patients who visited the Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology and underwent CBCT examination from January to December, 2021. The data with their complete clinical information (including clinical records, radiology request forms/reports, two-dimensional and three-dimensional imaging data) were included. Those who underwent CBCT examination for orthodontic or prosthodontics were excluded. The experience and training background of the endodontic specialists, the number of patients treated in the whole year, the objective and region of interest (ROI) of CBCT examination, technical parameters, such as machine type, field of view (FoV) and radiographic reports were collected and analyzed to evaluate the impact on diagnosis. Wilcoxon and Mann-Whitney tests were used to compare the distribution of CBCT ROI. Chi-squared test and pairwise comparison were used to compare the application of CBCT by endodontic specialists with different clinical experience (senior, middle and junior).@*RESULTS@#In 2021, a total of 3 308 CBCT scans were prescribed by 61 endodontic specialists who treated 34 952 patients throughout the year. 3 218 patients (male ∶female about 1 ∶2) amounting for 10% of the patients treated in the whole year who received CBCT scans with an median age of 35 years (28, 49). Around 98% CBCT examinations were performed after clinical examination and two-dimensional periapical radiographs were taken. The FoV of CBCT scanning less than 10 cm×10 cm accounted for 96% of the total number of the images. Among the 3 308 CBCT scans, 83% of the ROI were in posterior teeth, with a higher number of anterior teeth (Z=-2.278, P < 0.05). Maxillary and mandibular first molars accounted for 35% of the examined teeth. The objectives of CBCT scanning included three aspects: clarifying clinical diagnosis, guiding surgical and non-surgical endodontic treatment (including management of endodontic complications), and outcome assessment, accounting for 1 111 (34%), 1 745 (54%), 311 (10%), respectively. and the others 2%. In the diagnosis process, CBCT was mainly used for the diagnosis of chronic periapical periodontitis, root fracture, root resorption and dental trauma. In the study, 353 CBCT were used in the diagnosis of root fracture, with a positive diagnosis rate of 35% (125/353). 846 CBCT used to reveal the anatomy of the root canal system, of which 297 cases were used to find missed/extra canals after treatment failure, and 58% (171/297) were used to confirm the missed/extra canals. In the management of complications or errors, CBCT was mainly used to assist the diagnosis of perforation and to locate the separated instruments. In the study, 311 CBCT scans were used for outcome assessment, including 240 cases related to non-surgical treatment and 71 cases related to surgical endodontic treatment for follow-up or presence of clinical symptoms, and persistent lesions on 2D films. Among the 61 endodontic specialists who used CBCT, 23 (45%) were with senior experience, 15 (30%) with middle experience, and 23 (25%) with junior experience. The proportion of senior or junior experience prescribing CBCT examination was 10%, higher than that of middle experience (8%, χ12=39.4, χ22=29.1, P < 0.001). The application rate of chief endodontists was 18%, which was higher than that of associate chief endodontists (9%, χ12=139.4, P < 0.001). 31% (1 109/3 308) cases of diagnosis or treatment plans were changed after CBCT was taken.@*CONCLUSION@#Use of CBCT in endodontic practice could provide more clinical information, which is helpful for diagnosis, accurate treatment and prognosis evaluation.

Changing scanning angles on improving finish line trueness of the full crown preparation / 中华口腔医学杂志

Objective: To explore the effect of scanning methods on finish line trueness of the full crown preparation. Methods: The standard full crown preparation model of the right maxillary first molars was prepared by using the maxillary standard resin dentition model. The standard preparation was scanned by imetric scanner and data were used as the true value. CEREC Omnicam and 3Shape TRIOS were used to scan the standard preparation. According to the scanning methods, they were divided into parallel scanning group, occlusal wave scanning group and buccolingual wave scanning group. Each group was scanned repeatedly 6 times. The data were imported into Geomagic Studio 2013 software, and the local finish line image data of the mesial, distal, buccal and lingual regions of the full crown preparation were extracted respectively. Three-dimensional deviation analysis was performed with the reference true value, and the root- mean-square error (RMSE) was the evaluation index of scanning trueness. The statistical method was one-way ANOVA. Results: Parallel scanning group: in general, the RMSE value of complete finish lines of scanner B [(35±6) μm] was significantly lower than that of scanner A [(44±7) μm](P<0.05). After scanner A occlusal wave scanning, the RMSE values of the mesial and distal finish lines [(33±5) and (50±12) μm] were significantly lower than those of parallel scanning group (P<0.05). After buccal and lingual wave scanning, the RMSE values of local finish lines in the mesial, distal, buccal and lingual regions [(37±3), (50±6), (28±6) and (29±8) μm] were significantly lower than those in parallel scanning group [(45±9), (63±7), (38±3) and (40±3) μm] (P<0.05). No significant difference was found in the RMSE values of the mesial, distal, buccal and lingual regions of scanner B between parallel scanning group, occlusal wave scanning group and buccolingual scanning group (P>0.05). Conclusions: The scanning trueness of the full crown preparation finish line obtained by the active triangulation scanning equipment can be improved by changing the scanning method to wave scanning.

Effect analysis of myectomy guided by personalized three-dimensional reconstruction and printing in the treatment of obstructive hypertrophic cardiomyopathy / 中华外科杂志

Objective: To examine the clinical efficacy of myectomy guided by personalized three-dimensional reconstruction and printing for patients with obstructive hypertrophic cardiomyopathy. Methods: The clinical data of 28 patients with obstructive hypertrophic cardiomyopathy, who underwent septal myectomy guided by personalized three-dimensional reconstruction and printing in the Department of Cardiaovascular Surgery, Guangdong Provincial People's Hospital from May 2020 to December 2021, were retrospectively analyzed. There were 14 males and 14 females, aging (51.1±14.0) years (range: 18 to 72 years). Enhanced cardiac computed tomography images were imported into Mimics software for preoperative three-dimensional reconstruction. The direction of the short axial plane of each segment was marked perpendicularly to the interventricular septum on the long axial plane of the digital cardiac model, then the thickness was measured on each short axial plane. A figurative digital model was used to determine the extent of resection and to visualize mitral valve and papillary muscle abnormalities. Correlation between the length, width, thickness, and volume of the predicted resected myocardium and those of the surgically resected myocardium was assessed by Pearson correlation analysis or Spearman correlation analysis. The accuracy of detecting mitral valve and papillary muscle abnormalities of transthoracic echocardiography and three-dimensional reconstruction was also compared. Results: There was no death or serious complications like permanent pacemaker implantation, re-sternotomy for bleeding, low cardiac output syndrome, stroke, or multiple organ dysfunction syndromes in the whole group. Namely, the obstruction of the left ventricular outflow tract was effectively relieved. The systolic anterior motion of the anterior mitral valve leaflet was absent in all patients after myectomy. The length, width, and thickness of the predicted resected myocardium by three-dimensional reconstruction were significantly positively correlated with the length (R=0.65, 95%CI: 0.37 to 0.82, P<0.01), width (R=0.39, 95%CI: 0.02 to 0.67, P<0.01), and thickness (R=0.82, 95%CI: 0.65 to 0.92, P<0.01) of the surgically resected myocardium, while the relation of the volume of the predicted resected myocardium and the volume of the surgically resected myocardium was a strong positive correlation (R=0.88, 95%CI: 0.76 to 0.94, P<0.01). Importantly, the interventricular septal myocardial thickness measured by preoperative transthoracic echocardiography showed a moderate positive correlation with the volume of surgically resected myocardium (R=0.52, 95%CI: 0.19 to 0.75, P<0.01). During a follow-up of (14.4±6.8) months (range: 3 to 22 months), no death occurred, and 1 patient was readmitted for endocardial radiofrequency ablation due to atrial fibrillation. Conclusion: Personalized three-dimensional reconstruction and printing can not only visualize the intracardiac structure but also guide septal myectomy by predicting the thickness, volume, and extent of resected myocardium to achieve ideal resection.

Growth Regularity of Pulmonary Ground Glass Nodules Based on 3D Reconstruction Technology / 中国肺癌杂志

BACKGROUND@#Since the popularization of computed tomography (CT) technology, the detection rate of pulmonary ground glass nodules (GGNs) with imaging follow-up as the main management method has increased significantly. The purpose of this study is to quantitatively analyze the changes of pulmonary GGNs during the follow-up process with three-dimensional reconstruction technology, explore the natural progression of pulmonary GGNs, and provide effective basis for clinical guidance for patients to conduct reasonable management of nodules.@*METHODS@#A total of 115 cases of pulmonary GGNs with regular follow-up in the Combined Outpatient Department of Zhoushan Hospital from March 2015 to November 2022 were enrolled. Quantitative imaging features of nodules were extracted by semi-automatic segmentation of 3D Slicer software to evaluate the growth of nodules and clinical intervention during follow-up.@*RESULTS@#The average baseline age of the patients was (56.9±10.1) yr. The mean follow-up time was (48.8±18.9) months. The two-dimensional diameter of baseline CT scan was (7.9±2.9) mm, and the maximum three-dimensional diameter was (10.1±3.4) mm. The two-dimensional diameter of the last CT scan was (9.9±4.7) mm, and the maximum three-dimensional diameter was (11.4±5.1) mm. A total of 27 cases (23.5%) showed an increase during follow-up, with a median volume doubling time of 822 days and a median mass doubling time of 1,007 days. 32 cases were surgically resected, including 6 cases of invasive adenocarcinoma (IAC), 16 cases of minimally invasive adenocarcinoma (MIA), 8 cases of adenocarcinoma in situ (AIS) and 2 cases of atypical adenomatous hyperplasia (AAH). Five nodules underwent surgical intervention due to the progression of two-dimensional diameter, which was pathologically confirmed as pre-invasive lesions, but their three-dimensional maximum diameter showed no significant change. Nodular morphology, lobulated sign, spiculated sign and vacuole signs all promoted the growth of nodules in univariate analysis. There were significant differences in age, baseline diameter, mean CT value, median CT value, 10% and 90% percentile CT number between the growth group and the stable group (P<0.05). Multivariate Logistic regression analysis showed that age and average CT value were risk factors for nodule growth (P<0.05). Receiver-operating characteristic (ROC) curve analysis results indicated that the age ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU were more likely to accelerate the growth of GGNs. The maximum three-dimensional diameter ≥14.4 mm and the average CT value ≥-495.7 HU may be a higher malignant probability.@*CONCLUSIONS@#GGNs show an inert growth process, and the use of three-dimensional measurements during follow-up is of greater significance. For persistent glass grinding nodules ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU are more likely to increase. However, most nodules still have good prognosis after progression, and long-term follow-up is safe.

Sex Estimation of Medial Aspect of the Ischiopubic Ramus in Adults Based on Deep Learning / 法医学杂志

OBJECTIVES@#To investigate the reliability and accuracy of deep learning technology in automatic sex estimation using the 3D reconstructed images of the computed tomography (CT) from the Chinese Han population.@*METHODS@#The pelvic CT images of 700 individuals (350 males and 350 females) of the Chinese Han population aged 20 to 85 years were collected and reconstructed into 3D virtual skeletal models. The feature region images of the medial aspect of the ischiopubic ramus (MIPR) were intercepted. The Inception v4 was adopted as the image recognition model, and two methods of initial learning and transfer learning were used for training. Eighty percent of the individuals' images were randomly selected as the training and validation dataset, and the remaining were used as the test dataset. The left and right sides of the MIPR images were trained separately and combinedly. Subsequently, the models' performance was evaluated by overall accuracy, female accuracy, male accuracy, etc.@*RESULTS@#When both sides of the MIPR images were trained separately with initial learning, the overall accuracy of the right model was 95.7%, the female accuracy and male accuracy were both 95.7%; the overall accuracy of the left model was 92.1%, the female accuracy was 88.6% and the male accuracy was 95.7%. When the left and right MIPR images were combined to train with initial learning, the overall accuracy of the model was 94.6%, the female accuracy was 92.1% and the male accuracy was 97.1%. When the left and right MIPR images were combined to train with transfer learning, the model achieved an overall accuracy of 95.7%, and the female and male accuracies were both 95.7%.@*CONCLUSIONS@#The use of deep learning model of Inception v4 and transfer learning algorithm to construct a sex estimation model for pelvic MIPR images of Chinese Han population has high accuracy and well generalizability in human remains, which can effectively estimate the sex in adults.