Finite element analysis of a customized implant in PMMA coupled with the cranial bone.

This computational study investigates the effect of the Von Misses stresses and deformations distribution generated by coupling a customized cranial implant with its fixation system for anchoring in the cranial bone of a specific patient. Three simulations were carried out under static loads, in different areas of the implant and during the rest-activity; and another three simulations were considered preset maximum intracranial pressures. Anatomical models were obtained by computed tomography. The design of the device to be implanted was carried out by applying reverse engineering processes, from the corresponding computer-aided design (CAD) model of the bone structure of interest. Likewise, the anchoring system was modeled in detail. Loads were applied at three points on the custom implant. The stress distribution on the artificial plate and the implant-natural bone interface was analyzed. The distribution of the stresses caused by the internal load states on the plate and the anchoring system was also studied. The neurocranial reconstruction with the customized polymethylmethacrylate (PMMA)-based implant and the finite element analysis demonstrated that the fixation and coupling system of the bone-implant interface guarantees adequate protection for the internal structures of the restored area. In addition, the custom-designed and placed implant will not cause non-physiological harm to the patient. Nor will failures occur in the anchoring system.

Micro-computed tomographic evaluation of root canal morphology in mandibular first premolars from a Colombian population.

Dental anatomy can vary significantly between different populations from different countries. Dental anatomical variations are of great interest to the dental professional, especially to endodontists, since they can influence the outcome of endodontic treatment. The purpose of the present study was to describe the anatomical variations of the root canal in mandibular first premolars in a population from Colombia, using micro-computed tomography. Fifty mandibular first premolars were scanned on a SkyScan 1174 and the microcomputed tomographic images were reconstructed. Anatomy was assessed using three-dimensional models. The parameters used were: Vertucci's classification, area and volume, perimeter, circularity, and major and minor diameter at 1, 2 and 3 mm from the apical foramen. According to the Vertucci's classification, teeth were classified as: types I (40%), V (24%), VII (4%) and III (4%), with 28% not classifiable. C-shaped canals were found in 1.8% of the sample. Mean evaluations at 1, 2, 3 mm of the foramen were as follows, respectively: perimeter 1.07 ± 0.57, 1.27 ± 0.78 and 1.57 ± 0.84 mm; circularity 0.59 ± 0.19, 0.57 ± 0.20 and 0.56 ± 0.22; maximum diameter 0.41 ± 0.23, 0.48 ± 0.33 and 0.60 ± 0.37 mm; minimum diameter 0.24 ± 0.10, 0.26 0.11 and 0.21 ± 0.13 mm. Mean total area and volume were 61.27 ± 16.47 mm2 and 12.47 ± 4.95 mm3, respectively. There was wide anatomical variation in mandibular first premolars from Colombian individuals, reinforcing the need for proper anatomical knowledge to establish more effective strategies for endodontic treatment.

A anatomia dentária pode variar significativamente entre diferentes populações, de diferentes países. As variações anatômicas dentais são de grande interesse para o profissional da odontologia, principalmente para os endodontistas, pois podem influenciar no resultado do tratamento endodôntico. Descrever as variações anatômicas do canal radicular dos primeiros prémolares inferiores em uma população da Colômbia, usando a micro tomografia computadorizada. Cinquenta primeiros prémolares inferiores foram digitalizados em um SkyScan 1174 e as imagens tomográficas foram reconstruídas e a anatomia foi avaliada por meio de modelos tridimensionais. Os parâmetros utilizados foram: classificação de Vertucci, área e volume, perímetro, circularidade e diâmetros maior e menor a 1, 2 e 3 mm do forame apical. De acordo com a classificação de Vertucci, os dentes foram classificados em: tipos I (40%), V (24%), VII (4%) e III (4%), sendo 28% não classificáveis. Canais em forma de C foram encontrados em 1,8% da amostra. As avaliações médias em 1, 2, 3 mm do forame foram as seguintes, respectivamente: perímetro 1,07 ± 0,57, 1,27 ± 0,78 e 1,57 ± 0,84 mm; circularidade 0,59 ± 0,19, 0,57 ± 0,20 e 0,56 ± 0,22; diâmetro maior 0,41 ± 0,23, 0,48 ± 0,33 e 0,60 ± 0,37 mm; diâmetro menor 0,24 ± 0,10, 0,26 ± 0,11 e 0,21 ± 0,13 mm. A média da área total e do volume foram 61,27 ± 16,47 mm2 e 12,47 ± 4,95 mm3, respectivamente. Houve uma grande variação anatômica nos primeiros pré-molares inferiores de colombianos, reforçando a necessidade de conhecimento anatômico adequado para estabelecer estratégias mais eficazes para o tratamento endodôntico.

Micro-computed tomographic evaluation of root canal morphology in mandibular first premolars from a Colombian population / Avaliaçao microromográfica da morfologia interna de canais de primeiros pré-molares de uma populaçao colombiana

ABSTRACT Dental anatomy can vary significantly between different populations from different countries. Dental anatomical variations are of great interest to the dental professional, especially to endodontists, since they can influence the outcome of endodontic treatment. The purpose of the present study was to describe the anatomical variations of the root canal in mandibular first premolars in a populationfrom Colombia, using micro-computed tomography. Fifty mandibular first premolars were scanned on a SkyScan 1174 and the microcomputed tomographic images were reconstructed. Anatomy was assessed using three-dimensional models. The parameters used were: Vertucci's classification, area and volume, perimeter, circularity, and major and minor diameter at 1, 2 and 3 mm from the apical foramen. According to the Vertucci's classification, teeth were classified as: types I (40%), V (24%), VII (4%) and III (4%), with 28% not classifiable. C-shaped canals were found in 1.8% of the sample. Mean evaluations at 1, 2, 3 mm of the foramen were as follows, respectively: perimeter 1.07 ± 0.57, 1.27 ± 0.78 and 1.57 ± 0.84 mm; circularity 0.59 ± 0.19, 0.57 ± 0.20 and 0.56 ± 0.22; maximum diameter 0.41 ± 0.23, 0.48 ± 0.33 and 0.60 ± 0.37 mm; minimum diameter 0.24 ± 0.10, 0.26 ± 0.11 and 0.21 ± 0.13 mm. Mean total area and volume were 61.27 ± 16.47 mm2 and 12.47 ± 4.95 mm3, respectively. There was wide anatomical variation in mandibular first premolars from Colombian individuals, reinforcing the need for proper anatomical knowledge to establish more effective strategies for endodontic treatment.

RESUMO A anatomia dentària pode variar significativamente entre diferentes populagoes, de diferentes países. As variagoes anatómicas dentais sao de grande interesse para o profissionai da odontologia, principalmente para os endodontistas, pois podem influenciar no resultado do tratamento endodóntico. Descrever as variagoes anatómicas do canal radicular dos primeiros pré-molares inferiores em uma populagao da Colómbia, usando a micro tomografia computadorizada. Cinquenta primeiros pré-molares inferiores foram digitalizados em um SkyScan 1174 e as imagens tomográficas foram reconstruidas e a anatomia foi avaliada por meio de modelos tridimensionais. Os parámetros utilizados foram: classificagao de Vertucci, área e volume, perímetro, circularidade e diámetros maior e menor a 1, 2 e 3 mm do forame apical. De acordo com a classificagao de Vertucci, os dentes foram classificados em: tipos I (40%), V (24%), VII (4%) e III (4%), sendo 28% nao classificáveis. Canais em forma de C foram encontrados em 1,8% da amostra. As avaliaçoes médias em 1, 2, 3 mm do forame foram as seguintes, respectivamente: perímetro 1,07 ± 0,57, 1,27 ± 0,78 e 1,57 ± 0,84 mm; circularidade 0,59 ± 0,19, 0,57 ± 0,20 e 0,56 ± 0,22; diámetro maior 0,41 ± 0,23, 0,48 ± 0,33 e 0,60 ± 0,37 mm; diámetro menor 0,24 ± 0,10, 0,26 ± 0,11 e 0,21 ± 0,13 mm. A média da área total e do volume foram 61,27 ± 16,47 mm2 e 12,47 ± 4,95 mm3, respectivamente. Houve uma grande variaçâo anatómica nos primeiros pré-molares inferiores de colombianos, reforçando a necessidade de conhecimento anatómico adequado para estabelecer estratégias mais eficazes para o tratamento endodóntico.

Evaluation of a 3D printed female anatomical model for the hands on training of trans-obturator tape (TOT) and tension free vaginal tape (TVT) sling procedures / Evaluación de un modelo anatómico femenino impreso en 3D para el entrenamiento práctico de los procedimientos de cinta trans-obturadora (TOT) y cinta vaginal sin tensión (TVT)

Trans-obturator tape (TOT) and tension free vaginal tape (TVT) procedures are efficient treatment options, which reduce the surgical complications and provide adequate support to urethra in case of increased abdominal pressure to prevent stress urinary incontinence (SUI). The aim of this study is to evaluate the effect and efficacy of 3D printed female anatomical model on the training of TOT and TVT procedures. A 3D printed female anatomical model was produced for MedTRain3DModSim, Erasmus+ European Union project led by Turkey with the participation of Greece, Italy, Czech Republic and South Korea. Face and content validities of the model evaluated by the participants and the experts respectively. During two learning & teaching & training activities and a multiplier event of the project between 2016 and 2018; 41 medical students, 30 residents and 19 specialists of urology and gynecology were educated and performed TOT and TVT procedures with this model under the mentorship of 3 experts. All participants were assessed and scored for their achievement on both procedures with model according to 7 parameters by the experts. There was no statistical difference between the students and residents for each parameter. All the parameters of the students and specialists were statistically different. 3D anatomical models produced from real data and mimicking different types of tissues are suitable for basic anatomy education of students and residents, hands on training for junior surgeons before cadaveric courses in hybrid education system, surgical planning of the surgeons and informing the patients before the operation.

Los procedimientos de cinta transobturadora (TOT) y cinta vaginal sin tensión (TVT) son opciones de tratamiento eficientes, que reducen las complicaciones quirúrgicas y proporcionan un soporte adecuado a la uretra en caso de aumento de la presión abdominal para prevenir la incontinencia urinaria de esfuerzo (IUE). El objetivo de este estudio fue evaluar el efecto y la eficacia del modelo anatómico femenino impreso en 3D en el entrenamiento de los procedimientos TOT y TVT. Se produjo un modelo anatómico femenino impreso en 3D para MedTRain3DModSim, proyecto Erasmus + de la Unión Europea dirigido por Turquía con la participación de Grecia, Italia, la República Checa y Corea del Sur. Validez facial y de contenido del modelo fueron evaluados por los participantes y los expertos respectivamente. Durante dos actividades de aprendizaje, enseñanza y capacitación y un evento multiplicador del proyecto entre 2016 y 2018; 41 estudiantes de medicina, 30 residentes y 19 especialistas en urología y ginecología fueron capacitados y realizaron procedimientos TOT y TVT de este modelo bajo la tutoría de 3 expertos. Todos los participantes fueron evaluados y calificados por los expertos, por su logro en ambos procedimientos con el modelo de acuerdo con 7 parámetros. No hubo diferencia estadística entre los estudiantes y los residentes para cada parámetro. Todos los parámetros de los estudiantes y especialistas fueron estadísticamente diferentes. Los modelos anatómicos en 3D producidos a partir de datos reales e imitando diferentes tipos de tejidos son adecuados para la educación básica de anatomía de estudiantes y residentes. Además de ofrecer una capacitación práctica para los cirujanos antes de los cursos cadavéricos en el sistema educativo, y una planificación quirúrgica de los cirujanos e información para los pacientes antes de la cirugía.

Uso de nuevos recursos tecnológicos en la docencia de un curso de anatomía con orientación clínica para estudiantes de medicina / Use of new technological resources in the teaching of a clinical anatomy course for medicine students

El uso de recursos tecnológicos como material de apoyo en la docencia de anatomía humana tiene antecedentes históricos en Chile desde el siglo 19, con la llegada del primer modelo anatómico artificial. En conjunto con las tradicionales clases magistrales y lectura de los textos clásicos sobre la materia, durante los trabajos prácticos se presentaba al estudiante una serie de contenidos estrictamente anatómicos que posteriormente serían evaluados. Esta metodología de enseñanza se mantuvo hasta muy avanzado el siglo 20. Posteriormente con los avances en tecnología médica de las últimas décadas incorporados a la práctica clínica habitual, también debieron integrarse conocimientos sobre las estructuras anatómicas, en cuanto a su representación en los exámenes obtenidos mediante técnicas de imágenes médicas. Por esta razón para la formación de las nuevas generaciones de médicos, se han debido actualizar paulatinamente; la literatura básica integrando a ella contenidos clínicos, la metodología docente haciéndola participativa hacia el estudiante y en el último tiempo los materiales para trabajos prácticos, de manera que se logre un aprendizaje duradero, cuyos contenidos sean utilizados posteriormente en otras asignaturas básicas y clínicas. Previo a iniciar las actividades docentes en el laboratorio de anatomía de la nueva Escuela de Medicina de la Universidad de Tarapacá, Chile, la institución adquirió material de apoyo docente de última generación para complementar la enseñanza en los trabajos prácticos de anatomía. En este artículo se describirá la implementación de los nuevos recursos tecnológicos de apoyo docente en anatomía para nuestra escuela de medicina, entre los cuales se encuentran: modelos anatómicos impresos en tres dimensiones (3D) Erler-Zimmer®, cadáver humano sintético Syndaver®, mesa de disección digital 3D SECTRA® y su estación de trabajo complementaria. Todos estos materiales se unieron al uso de otros recursos tradicionales en la enseñanza de esta disciplina, para entregar los contenidos de la anatomía con un enfoque combinado.

The use of technological resources as assisting material in the teaching of human anatomy has been referenced in Chile since the 19th century with the first artificial anatomical model. In conjunction with traditional lectures and classical texts on the subject during practical work, the student was presented with a series of strictly anatomical contents that would later be evaluated. This teaching methodology was maintained until well into the 20th century. Subsequently, medical technology progress and innovation was integrated in clinical practice over the last decades. Further, knowledge of anatomical structures, in terms of their representation in exams obtained through medical imaging techniques was also consolidated. For this reason for the education of the new generations of medical doctors, a gradual update was required. These included basic clinical content literature, a teaching methodology with student participation, and use of materials for practical work to achieve learning techniques that would be useful in later courses. Prior to the beginning of the school year, the School of Medicine of the Universidad de Tarapacá acquired state of the art material to complement teaching in practical anatomy work for its anatomy laboratory. This article describes implementation of the new technological resources for educational support in anatomy for our school of medicine, among these are: anatomical models printed in three dimensions (3D) Erler-Zimmer®, synthetic human cadaver Syndaver®, SECTRA® 3D digital dissection table and complementary workstation. All of this material will be used in conjunction with other traditional resources when teaching anatomy, so as to provide an overall view of the contents in this subject area.

La estatua anatómica del Dr. Auzoux: primer modelo anatómico de uso docente en Chile / The anatomical statue of Dr. Auzoux: first anatomical model of teaching purposes in Chile

Llegada a Chile en 1846, la estatua anatómica del Dr. Auzoux fue comprada por el gobierno de la época para el museo de Historia Natural. En 1864, fue donada a la Escuela de Medicina, donde sirve a varias generaciones de estudiantes; es dada por perdida en 1923. Desde entonces fue utilizada despreocupadamente por los estudiantes y docentes, sin saber de su origen, hasta que se inicia su búsqueda, hallándose el año 2005 en regular estado de conservación. Para su restauración, se limpió y eliminó toda sustancia ajena al modelo. Luego, se realizó el registro visual de la "estatua" en conjunto y por separado,desarmándose por regiones para identificar cada una de sus partes, analizándose calidad de conservación del material utilizado, tipo de material, inscripciones y elementos de sujeción utilizadas en su elaboración. Todo el proceso fue respaldado con la toma de imágenes. La estatua correspondió a una figura humana de tamaño natural que representa a un hombre adulto de pie, sin su piel, construido de papel maché (cartón piedra). Su hemicuerpo derecho esta construido en bloque, apoyado desde su pie derecho en un vástago de fierro que termina en una base de tres puntas. Su hemicuerpo izquierdo presenta distintas partes articuladas entre sí por sistemas de ganchos de bronce y ajuste por argollas que permiten encajar sus piezas. Se compone de 26 piezas desmontables que tienen 92 partes en total desarmables y 2000 detalles, cada una identificada con un número En general, las piezas presentan desgaste en las zonas de unión o anclajes, con claro deterioro de su pintura, siendo las zonas más afectadas las que se encuentran expuestas más superficialmente en el modelo. Siendo esta estatua la pieza anatómica documentada más antigua del país y considerando el estado de deterioro de la misma, era imperioso iniciar el proceso de restauración para poder preservarla a las generaciones futuras de anatomistas.

Arrival in Chile in 1846, the anatomical statue of Dr. Auzoux is purchased by the government for the Museum of Natural History. In 1864, it was donated to the School of Medicine, serving several generations of students, and given up for lost in 1923. Since then was casually used by students and teachers, unaware of their origin, until it begins its search, being in 2005, in a regular condition. For restoration, it was cleaned every substance outside the model. Then, we carried out a visual record of the "statue" jointly and separately, disarming by regions to identify each of its parts, analyzing the conservation quality of the material used, type of material, inscriptions and fasteners used in its preparation. The whole process was supported by digital images. The statue corresponded to a life-size human figure representing an adult man standing without his skin, constructed of papier mache. The right hemisphere is built block, leaning from his right foot on a iron rod ending in a three-point basis. The left side of the body has different hinged together by systems bronze hooks and eyelets that allow adjustment parts fit parts. It consists of 26 removable parts with 92 parts total separable and 2000 details, each identified by a number. In general, the parts for wear in the joint areas or anchors, with clear deterioration of his painting, being more exposed surface areas in the model the most affected. Since this statue is the oldest documented anatomical object of the country and considering the state of disrepair of it, it was imperative to start the restoration process to preserve it for future generations of anatomists.

Modelo pélvico sintético como uma ferramenta didática efetiva comparada à pelve cadavérica / A synthetic three-dimensional pelvic model as an effective didactic tool compared to cadaveric pelvis

A anatomia é considerada matéria essencial à educação médica. Aulas práticas com uso de componentes anatômicos manipuláveis são fundamentais ao ensino e à aprendizagem. O objetivo deste estudo foi avaliar o Modelo Sintético de Pelve (Masp) como ferramenta didática, comparada à pelve cadavérica (PC) tradicionalmente utilizada, bem como a satisfação dos estudantes em relação a ambos os métodos. Sessenta e sete estudantes receberam aula teórica após teste teórico preliminar (TTP). Foram randomizados em três grupos: G1 teve aula prática tradicional (APT); G2, aula prática com Masp (APM); e G3 não teve aula prática. Um teste final (TTF) foi aplicado a todos os grupos. G1 e G2 submeteram-se à avaliação do método (AM). A análise estatística foi realizada utilizando-se Anova (Análise de Variância) e teste não paramétrico Mann-Whitney. No TTF, G3 apresentou escores mais baixos do que G1 (p = 0,041) e G2 (p = 0,000). Não foi encontrada diferença estatisticamente significante entre G1 e G2 (p >0,05). G2 apresentou maior satisfação com o método (p = 0,001). Concluiu-se que PC e Masp provaram ser ferramentas didáticas efetivas e que G2 mostrou maior satisfação.

Anatomy is considered a fundamental subject of medical education. Practical classes which involve the use of manipulable anatomic components are essential to teaching and learning. The aim of this study was to evaluate the synthetic pelvic model (SPM) as a didactic tool, compared to the traditionally- -used cadaveric pelvis (CP), as well as student satisfaction in relation to both methods. Sixty-seven students were given a theory class following the preliminary theoretical test (PTT). The study sample was randomized in three groups: G1 had a traditional practical class (TPC); G2 had a practical class with SPM (PCS); and G3 had no practical class. A final test (FTT) was applied to all the groups. G1 and G2 were subjected to method evaluation (ME). Statistical analysis was conducted using analysis of variance (ANOVA) and the Mann-Whitney U test. In the FTT, G3 presented scores lower than G1 (p = 0.041) and G2 (p = 0.000). No statistically significant difference was found between G1 and G2 (p >0.05). G2 presented greater satisfaction with the method (p = 0.001). In conclusion, both CP and SPM proved to be effective didactic tools and student satisfaction was greater with G2.

Estudio de la anatomía en cadáver y modelos anatómicos: impresión de los estudiantes / Study of anatomy in cadavers and anatomical models: impression of students

En la enseñanza de la anatomía humana diversos autores señalan que la base del conocimiento del cuerpo humano es el cadáver. Aprender anatomía con el recurso, cadáver, contribuye en gran medida a la comprensión de la forma, ubicación, relaciones, espacio y distancia de los diferentes órganos y estructuras del cuerpo humano. Los estudiantes de la Facultad de Medicina de la Universidad de La Frontera Temuco, Chile, tienen la posibilidad de trabajar en laboratorio con cadáveres y modelos anatómicos. Con el propósito de identificar la representación que tienen los estudiantes al trabajar con ambos recursos, realizamos un estudio cualitativo, utilizando la técnica de Redes Semánticas Naturales. La muestra estuvo constituida por 66 alumnos de la carrera de Medicina y 40 de Nutrición y Dietética, Se realizaron dos sesiones con los grupos de cada una de las carreras, en la primera se les entregó una hoja encuesta con la palabra estímulo "Anatomía-Cadáver" y en la otra sesión la palabra estímulo "Anatomía-Modelo Anatómico". En el análisis de los datos se obtuvieron los valores de la técnica: J, M, conjunto SAM y FMG. Para ambos grupos de estudiantes el poder trabajar con el recurso cadáver significó: estudio, cuerpo, aprendizaje y conocimiento, además para el grupo de Medicina se agrega el significado de respeto, ciencia y realizar disección. En relación con el recurso modelo anatómico significó: estudio, irreal, falso, invariable, fácil. Podemos señalar que ambos recursos cumplen con el objetivo de ser un instrumento que les permite estudiar, sin embargo existen diferencias conceptuales relevantes de ambos recursos.

In the teaching of human anatomy various authors have stated that the base knowledge of the human body is the cadaver. Learning anatomy through manipulation of the body contributes greatly to understanding shape, location, relationship, space and distance of various organs and structures of the human body. Faculty of Medicine students of the Universidad de La Frontera in Temuco, Chile have the opportunity to work with cadavers and anatomical models in the laboratory. In order to identify the representation students have while working with both resources, we conducted a qualitative study based on the Natural Semantic Networks technique. The sample consisted of 66 medical degree students, and 40 nutrition and diet degree students. Two sessions were conducted with students of each career. During the first survey they were given a survey form with the stimulus word "Anatomy ­Cadaver", and in the other session the stimulus word "Anatomy-Model". In the analysis data technique values were obtained: J, M, SAM and FMG set. For both groups of students the ability to work with the cadaver resource meant: study, body learning and knowledge; furthermore for the group of medical students the meaning of respect, science and dissection work were noted. In reference to the anatomical model resource it also meant: study, surreal, false, invariable and easier. We noted that both resources met the goal of being a tool which allows the students to study, however, with important conceptual differences of both resources.