Sex estimation based on foramen magnum: a three-dimensional geometric morphometrics approach / Estimación del sexo basado en el foramen magno: un enfoque de morfometría geométrica tridimensional

SUMMARY: The foramen magnum is an important topographic opening which connects cranial cavity and spinal canal. The analysis of the bone material established that there are differences in the shape of the foramen magnum between individuals. The aim of this study was to determine sex based on shape and size of foramen magnum using geometric morphometrics method. A study was performed on three-dimensional models (3D models) of 214 human skulls of known sex and known age (141 male skulls and 73 female skulls). The skulls are located at the museum of Medical Faculty, University of Sarajevo. Skulls belong to Bosnian population from the mid-twentieth century. All examined skulls were scanned with a laser scanner to obtain their 3D models. On 3D models of the examined skulls, four landmarks were marked on foramen magnum. Analysis of sex determination was performed using the MorphoJ program. Results of this study showed that there are sex differences in the shape and size of the foramen magnum. Sex determination based on the shape and size of the foramen magnum was showed 65.25 % accuracy for male and 63.01 % accuracy for female using geometric morphometrics method. Examination of the effect of size of foramen magnum on sexual dimorphism of shape of foramen magnum showed a statistically significant effect. Sex determination based just on the shape of foramen magnum using geometric morphometrics method was possible with 62.41 % accuracy for male and 58.90 % accuracy for female on examined sample. Sex differences on shape and size of foramen magnum were found using geometric morphometrics method on three-dimensional models of the examined skulls. The percentage of accuracy was higher for male based on the shape and size of the foramen magnum than for female.

El foramen magno es una importante abertura topográfica que conecta la cavidad craneal y el canal espinal. El análisis del material óseo estableció que existen diferencias en la forma del foramen magno entre individuos. El objetivo de este estudio fue determinar el sexo en función de la forma y el tamaño del foramen magno utilizando morfometría geométrica. El estudio se realizó en modelos tridimensionales (modelos 3D) de 214 cráneos humanos de sexo y edad conocidos (141 cráneos masculinos y 73 cráneos femeninos). Los cráneos se encuentran en el museo de la Facultad de Medicina de la Universidad de Sarajevo. Los cráneos pertenecen a población bosnia de mediados del siglo XX. Todos los cráneos examinados fueron escaneados con un escáner láser para obtener sus modelos 3D. En los modelos 3D de los cráneos examinados, se marcaron cuatro puntos de referencia en el foramen magno. El análisis de determinación de sexo se realizó utilizando el programa MorphoJ. Los resultados de este estudio mostraron que existen diferencias de sexo en la forma y el tamaño del foramen magno. La determinación del sexo basada en la forma y el tamaño del foramen magno mostró una precisión del 65,25 % para los hombres y del 63,01 % para las mujeres utilizando morfometría geométrica. El examen del efecto del tamaño del foramen magno sobre el dimorfismo sexual de la forma del foramen magno mostró un efecto estadísticamente significativo. La determinación del sexo basada solo en la forma del foramen magno utilizando morfometría geométrica fue posible con una precisión del 62,41 % para los hombres y del 58,90 % para las mujeres en la muestra examinada. Se encontraron diferencias de sexo en la forma y el tamaño del foramen magno utilizando morfometría geométrica en modelos tridimensionales de los cráneos examinados. El porcentaje de precisión fue mayor para los hombres en función de la forma y el tamaño del foramen magno que para las mujeres.

Antenatal Diagnosis of Parapagus Conjoined Twins: 3D Virtual and 3D Physical Models / Diagnóstico antenatal de gêmeos unidos parapagus: Modelos 3D virtuais e físicos

Abstract Conjoined twins (CTs) are a rare complication from monochorionic and monoamniotic twin pregnancies. We describe the use of 3D technologies, including 3D virtual and 3D physical models on prenatal evaluation of one parapagus CT. A 16-year-old G1P0 woman was referred for fetal magnetic resonance imaging (MRI) anatomical evaluation of a CT at 28 weeks of gestation. 3D images of the fetal surface were generated by the software during the examination for spatial comprehension of the relationship between the fetal parts. The pair of CTs died at the 32nd week of gestation, a few hours after cesarean section. 3D technologies are an important tool for parental counseling and preparation of the multidisciplinary care team for delivery and neonatal assistance and possible surgical planning for postnatal separation in CTs cases.

Resumo Gêmeos unidos (GUs) são uma complicação rara de gestações gemelares monocoriônicas e monoamnióticas. Descrevemos o uso de tecnologias 3D, incluindo modelos 3D virtuais e físicos, na avaliação pré-natal de GU parapagus. Mulher de 16 anos, G1P0, foi encaminhada para avaliação anatômica por ressonância magnética (RM) fetal de GU com 28 semanas de gestação. Imagens 3D da superfície fetal foram geradas pelo software durante o exame para compreensão espacial da relação entre as partes fetais. O par de GUs morreu na 32ª semana de gestação, poucas horas após a cesariana. As tecnologias 3D são uma importante ferramenta de aconselhamento dos pais e de preparação da equipe multiprofissional para o parto e a assistência neonatal, além de possível planejamento cirúrgico para separação pós-natal em casos de GUs.

3D Rapid Prototyping Heart Model Validation for Teaching and Training - A Pilot Project in a Teaching Institution

Abstract Introduction: Rapid prototyping is a process by which three-dimensional (3D) computerized surface models are converted into physical models. In this study, a 3D heart bio model was created using the rapid prototyping method and the accuracy of this heart model was assessed by clinicians. Methods: The two-dimensional images of normal heart from gated computed tomography scan datasets were used to create a 3D model of the heart. The slices were then processed using the software BioModroid and printed with the 3D printer. The evaluation of the model was performed by a questionnaire answered by four cardiothoracic surgeons, 12 cardiologists, five radiologists, and nine surgical registrars. Results: Eighty-six percent of the anatomy structures showed in this model scored 100% accuracy. Structures such as circumflex branch of left coronary artery, great cardiac vein, papillary muscle, and coronary sinus were each rated 77%, 70%, 70%, and 57% accurate. Among 30 clinicians, a total of 93% rated the model accuracy as good and above; 64% of the clinicians evaluated this model as an excellent teaching tool for anatomy class. As a visual aid for surgery or interventional procedures, the model was rated excellent (40%), good (50%), average (23%), and poor (3%); 70% of the clinicians scored the model as above average for training purpose. Overall, this 3D rapid prototyping cardiac model was rated as excellent (33%), good (50%), and average (17%). Conclusion: This 3D rapid prototyping heart model will be a valuable source of anatomical education and cardiac interventional management.

Novel condylar repositioning method for 3D-printed models / 대한악안면성형재건외과학회지

BACKGROUND: Along with the advances in technology of three-dimensional (3D) printer, it became a possible to make more precise patient-specific 3D model in the various fields including oral and maxillofacial surgery. When creating 3D models of the mandible and maxilla, it is easier to make a single unit with a fused temporomandibular joint, though this results in poor operability of the model. However, while models created with a separate mandible and maxilla have operability, it can be difficult to fully restore the position of the condylar after simulation. The purpose of this study is to introduce and asses the novel condylar repositioning method in 3D model preoperational simulation. METHODS: Our novel condylar repositioning method is simple to apply two irregularities in 3D models. Three oral surgeons measured and evaluated one linear distance and two angles in 3D models. RESULTS: This study included two patients who underwent sagittal split ramus osteotomy (SSRO) and two benign tumor patients who underwent segmental mandibulectomy and immediate reconstruction. For each SSRO case, the mandibular condyles were designed to be convex and the glenoid cavities were designed to be concave. For the benign tumor cases, the margins on the resection side, including the joint portions, were designed to be convex, and the resection margin was designed to be concave. The distance from the mandibular ramus to the tip of the maxillary canine, the angle created by joining the inferior edge of the orbit to the tip of the maxillary canine and the ramus, the angle created by the lines from the base of the mentum to the endpoint of the condyle, and the angle between the most lateral point of the condyle and the most medial point of the condyle were measured before and after simulations. Near-complete matches were observed for all items measured before and after model simulations of surgery in all jaw deformity and reconstruction cases. CONCLUSIONS: We demonstrated that 3D models manufactured using our method can be applied to simulations and fully restore the position of the condyle without the need for special devices.

Exatidão, precisão e reprodutibilidade de medidas dentárias em modelos de gessso e imagem tridimensional / Analyses and comparison of linear measurements performed on plaster models and three-dimensional images

O presente projeto desenvolvido em dois estudos visa avaliar: 1- a exatidão, precisão e reprodutibilidade de medições obtidas em modelos de gesso utilizando diferentes instrumentos de medidas e 2 ­ avaliar a influência do posicionamento da moldeira durante o tempo de presa do gesso na distorção dos modelos. Trinta modelos de gesso foram selecionados de maneira aleatória, preenchendo os seguintes requisitos de inclusão da amostra: 1)Presença dos incisivos, caninos, pré-molares e os primeiros molares permanentes em ambas as arcadas maxilar e mandibular; 2) Todos os dentes dos modelos terão que exibir morfologia normal; 3)Ausência de irregularidades no gesso proveniente de lesões cariosas e restaurações que possam afetar o diâmetro mésio-distal ou buco-lingual da coroa dentária; 4) Nenhum tratamento ortodôntico prévio. No estudo 1 as medições foram realizadas com três instrumentos: 1- Paquímetro digital da marca Mitutoyo Digimatic®, Mitutoyo (UK) Ltd, com os modelos posicionado sobre uma superfície plana; 2- Sistema MicroScribe 3DX (Immersion, San Jose, Calif): é um scanner 3D que grava a localização do ponto identificado com a extremidade de uma caneta. Colocando essa caneta em vários pontos do objeto a ser medido, o usuário pode coletar as coordenadas destes pontos e criar um modelo tridimensional. A digitalização é realizada com os modelos fixos num dispositivo preso a uma superfície plana. 3- Sistema O3d (widialabs©) no qual os modelos de gesso são escaneados utilizando-se um scanner de varredura produzindo uma imagem tridimensional. Com auxílio do software do programa os pontos a serem medidos são identificados e as medidas automaticamente registradas. As medidas lineares foram: tamanho dos dentes, trespasse horizontal, trespasse vertical, comprimento do arco, largura do arco. Com base nas medidas obtidas a confiabilidade do índice de irregularidade de Little e análise de Bolton foram testados. No segundo estudo as medidas de tamanho de dentes e distâncias inter-dentárias foram obtidas em imagens digitais pelo sistema O3d. Os dados obtidos foram analisados estatisticamente e revelaram que o sistema O3d é confiável para a realização de análise de modelos e que a posição da moldeira durante a presa não produz alterações dimensionais no modelo

The objective of the present work separated in two parts: 1- is to assess accuracy, precision and reproducibility of measurements obtained from plaster models by means of different instruments; 2 ­ evaluate the influence of tray position during the setting time of gypsum at model distortion. Thirty plaster models will be randomly chosen according to the inclusion requirements of the sample as follows: 1) Presence of incisors, canines, pre-molars and the permanent first molars in both maxillary and mandibular arches; 2) Normal morphology on every tooth of the models; 3) Absence of irregularities on the plaster due to carious lesions and restorations which may affect the mesiodistal or buccolingual diameter of the dental crown; 4) No previous orthodontic treatment. Three instruments will be used to make the measurements: 1- Mitutoyo Digimatic® digital pachymeter, Mitutoyo (UK) Ltd: position models on a flat surface and measure them manually; 2- MicroScribe 3DX System (Immersion, San Jose, Calif.) : with MicroScribe , a 3D scanner , register the location of a selected point marked with one end of a pen. By placing the pen on different points of the object to be measured, one can collect the coordinates and make a three dimensional model. Digitizing is performed by fixing the models on a device fixed on a flat surface. 3- O3d System (widialabs©): the plaster models image is scanned by means of a scanning scanner, thus creating a three dimensional image. With the help of the program software the points to be measured are identified and the measurements are automatically recorded. Linear measurements to be assessed are as follows: size of teeth, horizontal overlap, vertical overlap, arch length and arch width. From the collected data, dependability of both Little irregularity index and Bolton analysis will be tested. At the second part of the study the measures of teeth size and inter dental distance was obtained with digital images through the O3d system. The data was statistically analyzed and reveal that the O3d system is trustworthy for model analyzed and the tray positioning during the setting time don't produce dimensions modification in the model

Estudo de neurofisiologia associado com modelos tridimensionais construídos durante o aprendizado / Neurophysiology study Associated with three-dimensionalmodels constructed during the learning

O estudo das vias e estruturas do sistema neural apresenta séria dificuldade para o aprendizado dos discentes da área da saúde, principalmente nos estudos neurofisiológicos e neuroanatômicos. Para minimizar as dificuldades da observação de peças anatômicas, que nem sempre estão à disposição nas várias faculdades e que, quando presentes, seu pequeno tamanho e inadequado preparo impedem uma observação mais acurada foi realizada a construção de modelos neuroanatômicos voltados para o estudo das vias e estruturas de difícil acesso no sistema neural central e periférico pelos discentes do terceiro período do curso de Fisioterapia das Faculdades Integradas Pitágoras de Montes Claros - MG nos dois semestres do ano de 2004. O objetivo foi de propiciar a aquisição de conhecimento através de trabalhos manuais e minimizar os efeitos estressantes de tão somente leitura e observação de aulas expositivas. Visando um custo reduzido os modelos foram confeccionados com madeiras cortadas com uma serra tico-tico, tintas para tecidos, barbantes e arames. Uma vez finalizado o trabalho, realizou-se um seminário para a apresentação dos vários modelos. Os modelos tridimensionais aumentados permitiram melhor estudo das áreas neurais microscópicas e sua confecção facilitou e motivou os discentes no estudo da disciplina de neurofisiologia efetivando uma forma mais ousada de ensino com a colaboração dos discentes no processo de ensino-aprendizado, exercendo um efeito reforçador na melhor preparação do professor para o ensino, além de contribuir para evitar o sacrifício de animais de laboratório.

The study of the ways and structures of the neural system represents serious difficulty to thestudents of the health area, mainly in the neurophysiologic and neuranatomic studies. To minimize the difficulties of the anatomical pieces observation, that nor always are available in some colleges and that, when they are, its small size andinadequated preparation hinder a more accurated observation, it was realized the construction of neuranatomic models directed to the study of the ways and structures of difficult access in the Central and Peripheral Neural System by the students of the third period of the course of Physiotherapy of the Faculdades Integradas Pitágoras de Montes Claros - MG,in the two semesters of 2004,. The objective was to propitiate the acquisition of knowledge through manual works and tominimize the stressing effects of only reading and observation of expositive classes. Aiming at a reduced cost, the modelshad been confectioned with wood cutted with a jig saw, inks for textile, strings and wire. After to finalize the work, it was performed a seminary, for the presentation of the several models. The increased three-dimensional models had allowed a better study of microscopical neural areas and its confection by the students facilitated and motivated them in the Neurophysiology discipline study, effecting a bolder form of teaching with the contribution of the students in the teachlearning process, exerting a stiffener effect in the best preparation of the professor for education, beyond contributing to prevent the sacrifice of laboratory animals.