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.

Protocolo para la medición de espacios vacíos dentro de la obturación endodóntica con microtomografía / A protocol for the measurement of voids within the endodontic filling with microtomography

La microtomografía es un estudio que utiliza la ra-diación X para obtener imágenes de tamaños de mi-lésimas de milímetros y de alta resolución. Las imá-genes 2D son procesadas por diferentes softwares para lograr obtener volúmenes capaces de ser ana-lizados tridimensionalmente. La microtomografía es el estudio de elección a la hora de evaluar caracte-rísticas muy pequeñas con gran precisión. La obtu-ración endodóntica buscar lograr un sellado que no tenga espacios vacíos dentro de la masa de obtura-ción. Esto es importante debido a que los poros pue-den permitir, si están en contacto con la pared den-tinaria, la entrada de microorganismos al conducto radicular. El objetivo de este trabajo fue describir el procedimiento para el análisis y visualización de los espacios vacíos dentro de la obturación endodónti-ca, utilizando la microtomografía de rayos x, y esta-blecer un protocolo para ser utilizado por cualquier investigador(AU)

Microtomography is a study that uses X-radiation to obtain high-resolution images of sizes of thousandths of millimeters. The 2D images are processed by different software to obtain volumes capable of being analyzed three-dimensionally. Microtomography is the study of choice when evaluating very small features with great precision. Endodontic filling seeks to achieve a seal that does not have voids within the filling obturation. This is important because the voids can allow, if they are in contact with the dentin wall, the entry of microorganisms into the root canal. The objective of this work was to describe the procedure for the analysis and visualization of voids within the endodontic filling using microtomography and to establish the protocol to be used by any researcher (AU)

Non-invasive imaging of pathological scars using a portable handheld two-photon microscope / 中华医学杂志(英文版)

BACKGROUND@#Pathological scars are a disorder that can lead to various cosmetic, psychological, and functional problems, and no effective assessment methods are currently available. Assessment and treatment of pathological scars are based on cutaneous manifestations. A two-photon microscope (TPM) with the potential for real-time non-invasive assessment may help determine the under-surface pathophysiological conditions in vivo . This study used a portable handheld TPM to image epidermal cells and dermal collagen structures in pathological scars and normal skin in vivo to evaluate the effectiveness of treatment in scar patients.@*METHODS@#Fifteen patients with pathological scars and three healthy controls were recruited. Imaging was performed using a portable handheld TPM. Five indexes were extracted from two dimensional (2D) and three dimensional (3D) perspectives, including collagen depth, dermo-epidermal junction (DEJ) contour ratio, thickness, orientation, and occupation (proportion of collagen fibers in the field of view) of collagen. Two depth-dependent indexes were computed through the 3D second harmonic generation image and three morphology-related indexes from the 2D images. We assessed index differences between scar and normal skin and changes before and after treatment.@*RESULTS@#Pathological scars and normal skin differed markedly regarding the epidermal morphological structure and the spectral characteristics of collagen fibers. Five indexes were employed to distinguish between normal skin and scar tissue. Statistically significant differences were found in average depth ( t = 9.917, P <0.001), thickness ( t = 4.037, P <0.001), occupation ( t = 2.169, P <0.050), orientation of collagen ( t = 3.669, P <0.001), and the DEJ contour ratio ( t = 5.105, P <0.001).@*CONCLUSIONS@#Use of portable handheld TPM can distinguish collagen from skin tissues; thus, it is more suitable for scar imaging than reflectance confocal microscopy. Thus, a TPM may be an auxiliary tool for scar treatment selection and assessing treatment efficacy.

O-arm navigation versus C-arm navigation for guiding percutaneous long sacroiliac screws placement in treatment of Denis type Ⅱ sacral fractures / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness of O-arm navigation and C-arm navigation for guiding percutaneous long sacroiliac screws in treatment of Denis type Ⅱ sacral fractures.@*METHODS@#A retrospective study was conducted on clinical data of the 46 patients with Denis type Ⅱ sacral fractures between April 2021 and October 2022. Among them, 19 patients underwent O-arm navigation assisted percutaneous long sacroiliac screw fixation (O-arm navigation group), and 27 patients underwent C-arm navigation assisted percutaneous long sacroiliac screw fixation (C-arm navigation group). There was no significant difference in gender, age, causes of injuries, Tile classification of pelvic fractures, combined injury, the interval from injury to operation between the two groups ( P>0.05). The intraoperative preparation time, the placement time of each screw, the fluoroscopy time of each screw during placement, screw position accuracy, the quality of fracture reduction, and fracture healing time were recorded and compared, postoperative complications were observed. Pelvic function was evaluated by Majeed score at last follow-up.@*RESULTS@#All operations were completed successfully, and all incisions healed by first intention. Compared to the C-arm navigation group, the O-arm navigation group had shorter intraoperative preparation time, placement time of each screw, and fluoroscopy time, with significant differences ( P<0.05). There was no significant difference in screw position accuracy and the quality of fracture reduction ( P>0.05). There was no nerve or vascular injury during screw placed in the two groups. All patients in both groups were followed up, with the follow-up time of 6-21 months (mean, 12.0 months). Imaging re-examination showed that both groups achieved bony healing, and there was no significant difference in fracture healing time between the two groups ( P>0.05). During follow-up, there was no postoperative complications, such as screw loosening and breaking or loss of fracture reduction. At last follow-up, there was no significant difference in pelvic function between the two groups ( P>0.05).@*CONCLUSION@#Compared with the C-arm navigation, the O-arm navigation assisted percutaneous long sacroiliac screws for the treatment of Denis typeⅡsacral fractures can significantly shorten the intraoperative preparation time, screw placement time, and fluoroscopy time, improve the accuracy of screw placement, and obtain clearer navigation images.

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.

3D Bitemark Analysis in Forensic Odontology Utilizing a Smartphone Camera and Open-Source Monoscopic Photogrammetry Surface Scanning

Abstract Bitemark analysis is a challenging procedure in the field of criminal case investigation. The unique characteristics of dentition are used to find the best match between the existing patterned injury and the suspected perpetrator in bitemark identification. Bitemark analysis accuracy can be influenced by various factors, including biting pressure, tooth morphology, skin elasticity, dental cast duplication, timing, and image quality. This review article discusses the potential of a smartphone camera as an alternative method for 3D bitemark analysis. Bitemark evidence on human skin and food should be immediately recorded or duplicated to retrieve long-lasting proof, allowing for a sufficient examination period. Various studies utilizing two-dimensional (2D) and three-dimensional (3D) technologies have been developed to obtain an adequate bitemark analysis. 3D imaging technology provides accurate and precise analysis. However, the currently available method using an intraoral scanner (IOS) requires high-cost specialized equipment and a well-trained operator. The numerous advantages of monoscopic photogrammetry may lead to a novel method of 3D bitemark analysis in forensic odontology. Smartphone cameras and monoscopic photogrammetry methodology could lead to a novel method of 3D bitemark analysis with an efficient cost and readily available equipment.

Simultaneous implantation and tooth preparation technology guided by 3D-printed guide / 华西口腔医学杂志

Using digital technologies in concurrently performing missing tooth implantation and preparation of remaining teeth is a solution to reduce the number of visits and improve efficiency. This paper proposes a digital process for simultaneously implanting and preparing teeth. It integrates implant surgical guide and 3D-printed tooth preparation guide into a single guide and completes guided implant placement and precise tooth preparation. Based on "repair-oriented" virtual implant planning, the implant surgical guide can improve the efficiency and predictability of implant placement, and its linear accuracy is about 1 mm. The tooth preparation guide precisely guides tooth preparation and restoration space visualization, ensuring the quality of the tooth preparation. The two guides have different design accuracy requirements, and thus their combination improves the overall guiding accuracy requirements. The concurrent application of the two guides minimizes the clinical operation time, number of visits, and economic burden of patients.

Three-dimensional reconstruction reveals the correlation between the extent of alveolar clefts and secondary nasal deformity in adults / 华西口腔医学杂志

OBJECTIVES@#This study aimed to explore the relationship between alveolar cleft and secondary nasal deformity post unilateral cleft lip repair in adults.@*METHODS@#A total of 27 patients aged 16-30 years old with unilateral secondary nasal deformity and alveolar cleft were included, 13 of whom underwent bone grafting. Spiral CT data of all preoperative and postoperative patients who had alveolar bone grafting were collected. Then, Mimics software was used for three-dimensional reconstruction to evaluate the correlation between the width, height, and volume of the alveolar cleft and those of the nasal deformity. The difference in nasal deformity before and after alveolar bone grafting was also explored.@*RESULTS@#The width of the alveolar cleft was positively correlated with the difference in bilateral nostril floor width (P<0.05). As the effective depth of the alveolar cleft increased, the sub-alare inclination angle largened (P<0.05). However, no significant difference was found in the nasal deformity between before and after alveolar bone grafting.@*CONCLUSIONS@#Alveolar cleft is closely related to secondary nasal deformities post unilateral cleft lip repair, especially nasal floor deformities. Alveolar bone grafting benefits adult patients for the improvement of secondary nasal deformities post unilateral cleft lip repair.

Comparison of screw placement guided by O-arm navigation and ultrasound volume navigation in minimally invasive transforaminal lumbar interbody fusion / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness of O-arm navigation and ultrasound volume navigation (UVN) in guiding screw placement during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery.@*METHODS@#Sixty patients who underwent MIS-TLIF surgery for lumbar disc herniation between June 2022 and June 2023 and met the selection criteria were included in the study. They were randomly assigned to group A (screw placement guided by UVN during MIS-TLIF) or group B (screw placement guided by O-arm navigation during MIS-TLIF), with 30 cases in each group. There was no significant difference in baseline data, including gender, age, body mass index, and surgical segment, between the two groups ( P>0.05). Intraoperative data, including average single screw placement time, total radiation dose, and average single screw effective radiation dose, were recorded and calculated. Postoperatively, X-ray film and CT scans were performed at 10 days to evaluate screw placement accuracy and assess facet joint violation. Pearson correlation and Spearman correlation analyses were used to observe the relationship between the studied parameters (average single screw placement time and screw placement accuracy grading) and BMI.@*RESULTS@#The average single screw placement time in group B was significantly shorter than that in group A, and the total radiation dose of single segment and multi-segment and the average single screw effective radiation dose in group B were significantly higher than those in group A ( P<0.05). There was no significant difference in the total radiation dose between single segment and multiple segments in group B ( P>0.05), while the total radiation dose of multiple segments was significantly higher than that of single segment in group A ( P<0.05). No significant difference was found in the accuracy of screw implantation between the two groups ( P>0.05). In both groups, the grade 1 and grade 2 screws broke through the outer wall of the pedicle, and no screw broke through the inner wall of the pedicle. There was no significant difference in the rate of facet joint violation between the two groups ( P>0.05). In group A, both the average single screw placement time and screw placement accuracy grading were positively correlated with BMI ( r=0.677, P<0.001; r=0.222, P=0.012), while in group B, neither of them was correlated with BMI ( r=0.224, P=0.233; r=0.034, P=0.697).@*CONCLUSION@#UVN-guided screw placement in MIS-TLIF surgery demonstrates comparable efficiency, visualization, and accuracy to O-arm navigation, while significantly reducing radiation exposure. However, it may be influenced by factors such as obesity, which poses certain limitations.

Three-dimensional reconstruction of femur based on Laplace operator and statistical shape model / 生物医学工程学杂志

Reconstructing three-dimensional (3D) models from two-dimensional (2D) images is necessary for preoperative planning and the customization of joint prostheses. However, the traditional statistical modeling reconstruction shows a low accuracy due to limited 3D characteristics and information loss. In this study, we proposed a new method to reconstruct the 3D models of femoral images by combining a statistical shape model with Laplacian surface deformation, which greatly improved the accuracy of the reconstruction. In this method, a Laplace operator was introduced to represent the 3D model derived from the statistical shape model. By coordinate transformations in the Laplacian system, novel skeletal features were established and the model was accurately aligned with its 2D image. Finally, 50 femoral models were utilized to verify the effectiveness of this method. The results indicated that the precision of the method was improved by 16.8%-25.9% compared with the traditional statistical shape model reconstruction. Therefore, the method we proposed allows a more accurate 3D bone reconstruction, which facilitates the development of personalized prosthesis design, precise positioning, and quick biomechanical analysis.

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.