Dysphagia as a primary manifestation of basilar impression: A case report.

Secondary basilar invagination or basilar impression is an anomaly at the craniovertebral junction where the odontoid process prolapses into the foramen magnum with the risk of compressing adjacent structures and obstructing the proper flow of cerebrospinal fluid (CSF). The incidence is less than 1% in the general population and occurs mainly in the first three decades of life when it is associated with malformations of the neuroaxis. In older age, the main aetiologies are diseases that alter bone mineral density. The clinical course is usually progressive and the most common symptoms are asthenia, cervical pain and restricted movement, but also dysphonia, dyspnoea and dysphagia. It is a progressive disease which, if left untreated, can cause severe neurological damage and death. We report the case of a 79-year-old woman with osteoporosis and progressive dysphagia leading to severe malnutrition, which conditioned the decision not to intervene due to the high perioperative risk.

Revisión sistemática de las aplicaciones y límites de la impresión 3D en la cirugía de raquis / Systematic review of the utility and limits of 3D printing in spine surgery

Objetivo: El objetivo principal de este estudio ha sido demostrar por qué la impresión aditiva permite hacer más visibles y entendibles los procesos patológicos quirúrgicos complejos que afectan al raquis, aumentando la precisión, la seguridad y la fiabilidad del procedimiento quirúrgico.MetodologíaSe realizó una revisión sistemática de los trabajos publicados en los últimos 10 años, sobre la cirugía de raquis asistida por impresión 3D, de acuerdo con la declaración PRISMA 2020. Con las palabras clave «printing 3D» y «spine surgery» se hicieron búsquedas en las bases de datos Pubmed, Embase, Cochrane Database of Systematic Reviews, Google Scholar y Opengrey, que se completó con la búsqueda manual a través de la lista de referencias bibliográficas de los artículos que fueron seleccionados siguiendo los criterios de inclusión y exclusión definidos.ResultadosDel análisis de los 38 estudios seleccionados resultó que la impresión 3D es útil en la planificación quirúrgica, en la enseñanza médica, en la relación médico-paciente, así como en el diseño de plantillas de navegación e implantes de raquis y, en investigación, ofreciendo un magnífico apoyo al proceder quirúrgico.ConclusionesEl uso de biomodelos impresos de forma tridimensional permite: hacer más visibles y entendibles los procesos patológicos quirúrgicos complejos que afectan al raquis; aumentar la exactitud, precisión y seguridad del procedimiento quirúrgico; y abrir la posibilidad de poner en práctica tratamientos personalizados, fundamentalmente en la cirugía tumoral. (AU)

Objective: The main objective of this study has been to demonstrate why additive printing allows to make complex surgical pathological processes that affect the spine more visible and understandable, increasing precision, safety and reliability of the surgical procedure.MethodsA systematic review of the articles published in the last 10 years on 3D printing-assisted spinal surgery was carried out, in accordance with PRISMA 2020 declaration. Keywords «3D printing» and «spine surgery» were searched in Pubmed, Embase, Cochrane Database of Systematic Reviews, Google Scholar and Opengrey databases, which was completed with a manual search through the list of bibliographic references of the articles that were selected following the defined inclusion and exclusion criteria.ResultsFrom the analysis of the 38 selected studies, it results that 3D printing is useful in surgical planning, medical teaching, doctor–patient relationship, design of navigation templates and spinal implants, and research, optimizing the surgical process by focusing on the patient, offering magnificent support during the surgical procedure.ConclusionsThe use of three-dimensional printing biomodels allows: making complex surgical pathological processes that affect the spine more visible and understandable; increase the accuracy, precision and safety of the surgical procedure, and open up the possibility of implementing personalized treatments, mainly in tumor surgery. (AU)

C1–C2 intraarticular distraction with anterior cervical cages for basilar invagination realignment: Operative technique nuances and review of literature

Neurosurgical management of basilar invagination (BI) has traditionally been aimed at direct cervicomedullary decompression through transoral dens resection or suboccipital decompression with supplemental instrumented fixation. Dr. Goel introduced chronic atlantoaxial dislocation (AAD) as the etiology in most cases of BI and described a technique for distracting the C1–C2 joint with interfacet spacers to achieve reduction and anatomic realignment. We present our modification to Goel’s surgical technique, in which we utilize anterior cervical discectomy (ACD) cages as C1–C2 interfacet implants. A young adult male presented to our institution with BI, cervicomedullary compression, occipitalization of C1, and Chiari 1 malformation. There was AAD of C1 over the C2 lateral masses. This reduced some with preoperative traction. He underwent successful C1–C2 interfacet joint reduction and arthrodesis with anterior cervical discectomy (ACD) cages and concomittant occiput to C2 instrumented fusion. BI can be effectively treated through reduction of AAD and by utilizing ACD cages as interfacet spacers. (AU)

El tratamiento neuroquirúrgico tradicional para la impresión basilar es principalmente a través de un abordaje trans-oral para la resección del proceso odontoide, seguido de una descompresión suboccipital con instrumentación posterior cervical. Dr. Goel presenta la dislocación atlanto-axial (AA) como una de las etiologías principales en los casos de impresión basilar. A su vez, describió la técnica quirúrgica que incluye la distracción de la articulación AA con cajas para fusión permitiendo la reducción y reajuste anatómico cervical. En este artículo presentamos una variación a la técnica quirúrgica del Dr. Goel en el cual utilizamos implantes utilizados en la discectomía y fusión cervical anterior (DFCA) para la articulación facetaria de C1–C2. Presentamos un paciente adulto masculino que evaluamos en nuestra institución con impresión basilar, compresión cérvico-medular, fusión occipital con el atlas y malformación de Chiari tipo 1. En adición, el paciente tenía evidencia radiográfica de dislocación AA. Se logro obtener reducción mínima de la impresión basilar con tracción cervical pre-operatoria. Luego, se sometió al tratamiento quirúrgico que consistió en el uso de implantes cervicales para la reducción y fusión de la articulación facetaria de C1–C2 complementado por instrumentación y fusión craneocervical. Esta técnica presentada sugiere que la reducción y reajuste anatómico cervical de la dislocación AA con implantes utilizados para DFCA puede ser efectivo para el tratamiento de impresión basilar. (AU)

[Translated article] Mechanical resistance of polylactic acid bone matrices developed by 3D printing for the reconstruction of bone defects.

INTRODUCTION: Bone defects are one of the main limitations in orthopaedic surgery and traumatology. For this reason, multiple bone replacement systems have been developed, either by prosthetic implant or by substitution with osteoforming substances, whose limitations are their survival and lack of structurality, respectively. The objective of this work is the generation of a new material for the creation of biologically active structures that have sufficient tensile strength to maintain the structure during remodelling. MATERIAL AND METHODS: A new filament based on the fusion of natural polylactide acid (PLA) powder was designed for the generation of pieces by means of fused deposition modelling (FDM) on which to carry out tensile mechanical tests of osteosynthesis material. A total of 13 groups with different cortical thickness, filling and layer height were carried out, with 10 tensile tests in each group, defining the tensile breaking limit for each group. The regression lines for each group and their mechanical resistance to traction on the filament used were determined. RESULTS: The filament ratio per contact surface unit with the osteosynthesis used was the main determinant of the mechanical resistance to traction, either at the expense of the increase in cortical thickness or by the increase in the percentage of cancellous bone filling. Layer height had a minor effect on tensile strength. The regression value was high for cortical thickness and cancellous filling, being elements with a predictable biomechanical behaviour. CONCLUSIONS: The new methodology allows the creation of personalised neutral and implantable PLA bone matrices for the reconstruction of large bone defects by means of 3D printing by FDM with a mechanical resistance to traction greater than that of current biological support structures.

C1-C2 intraarticular distraction with anterior cervical cages for basilar invagination realignment: Operative technique nuances and review of literature.

Neurosurgical management of basilar invagination (BI) has traditionally been aimed at direct cervicomedullary decompression through transoral dens resection or suboccipital decompression with supplemental instrumented fixation. Dr. Goel introduced chronic atlantoaxial dislocation (AAD) as the etiology in most cases of BI and described a technique for distracting the C1-C2 joint with interfacet spacers to achieve reduction and anatomic realignment. We present our modification to Goel's surgical technique, in which we utilize anterior cervical discectomy (ACD) cages as C1-C2 interfacet implants. A young adult male presented to our institution with BI, cervicomedullary compression, occipitalization of C1, and Chiari 1 malformation. There was AAD of C1 over the C2 lateral masses. This reduced some with preoperative traction. He underwent successful C1-C2 interfacet joint reduction and arthrodesis with anterior cervical discectomy (ACD) cages and concomittant occiput to C2 instrumented fusion. BI can be effectively treated through reduction of AAD and by utilizing ACD cages as interfacet spacers.

Systematic review of the utility and limits of 3D printing in spine surgery.

OBJECTIVE: The main objective of this study has been to demonstrate why additive printing allows to make complex surgical pathological processes that affect the spine more visible and understandable, increasing precision, safety and reliability of the surgical procedure. METHODS: A systematic review of the articles published in the last 10 years on 3D printing-assisted spinal surgery was carried out, in accordance with PRISMA 2020 declaration. Keywords "3D printing" and "spine surgery" were searched in Pubmed, Embase, Cochrane Database of Systematic Reviews, Google Scholar and Opengrey databases, which was completed with a manual search through the list of bibliographic references of the articles that were selected following the defined inclusion and exclusion criteria. RESULTS: From the analysis of the 38 selected studies, it results that 3D printing is useful in surgical planning, medical teaching, doctor-patient relationship, design of navigation templates and spinal implants, and research, optimizing the surgical process by focusing on the patient, offering magnificent support during the surgical procedure. CONCLUSIONS: The use of three-dimensional printing biomodels allows: making complex surgical pathological processes that affect the spine more visible and understandable; increase the accuracy, precision and safety of the surgical procedure, and open up the possibility of implementing personalized treatments, mainly in tumor surgery.

Solutions based on three-dimensional technologies for the practice and teaching of biomedical sciences

Introduction: Three-dimensional printing is one of the technologies that promote change at an economic and social level, and one of the fundamental elements of industry 4.0. It has enormous potential for the future of medicine, establishing itself as a new paradigm. Despite its advantages, its use in our environment is incipient. Objective: To design and develop solutions based on three-dimensional technologies for the teaching and practice of biomedical sciences. Materials and methods: A technological development investigation was carried out between the Center for Assisted and Sustainable Manufacturing of the University of Matanzas and Matanzas University of Medical Sciences, between September 2019 and July 2022. The designs and fabrications were made from the acquisition of computed tomography images, or from a surface scanner, which were then processed, converted into Standard Tessellation Language format, printed, and post-processed. Virtual designs were developed using computer-aided design software. Results: Various solutions were developed including prototypes: biomodels for craniosynostosis repair and anatomical figures, custom cranial prosthesis mold, hand prosthesis, O2 line splitters, tissue scaffolds, syringe gun, face shields, breast prosthesis; autologous restoration mold and tissue expander. Conclusions: In all areas of application of this technology in medicine―except the printing of medicines, in the current context―, it is feasible to obtain solutions in the territory of Matanzas. It is therefore imperative that managers and the medical community in general, begin to acquire awareness, knowledge, and experience to ensure the optimal use of this technology.

Introducción: La impresión tridimensional es una de las tecnologías que promueve el cambio a nivel económico y social, y uno de los elementos fundamentales de la industria 4.0. Asimismo, constituye un enorme potencial para el futuro de la medicina, estableciéndose como un nuevo paradigma. A pesar de sus ventajas, su explotación en nuestro medio es incipiente. Objetivos: Diseñar y desarrollar soluciones basadas en tecnologías tridimensionales para la enseñanza y la práctica de las ciencias biomédicas. Materiales y métodos: Se realizó una investigación colaborativa, de desarrollo tecnológico entre el Centro de Fabricación Asistida y Sostenible de la Universidad de Matanzas y la Universidad de Ciencias Médicas de Matanzas, entre septiembre de 2019 y julio de 2022. Los diseños y fabricaciones se realizaron a partir de la adquisición de imágenes de tomografía computarizada, o desde un escáner de superficie, las que luego se procesaron, se convirtieron en formato Standard Tessellation Language, se imprimieron y posprocesaron. Los diseños virtuales se desarrollaron empleando un software de diseño asistido por computadora. Resultados: Se desarrollaron varias soluciones que incluyen varios prototipos: biomodelos para reparación de craneosinostosis y figuras anatómicas, molde de prótesis craneal personalizada, prótesis de mano, divisores de líneas de O2, andamios tisulares, pistola portajeringas, protectores faciales, prótesis de mama, molde para restauración autóloga y expansor tisular. Conclusiones: En todas las áreas de aplicación de esta tecnología en medicina―salvo en la impresión de medicamentos, en el contexto actual―, es factible obtener soluciones en el territorio de Matanzas. Es un imperativo, pues, que directivos y la comunidad médica en general, comiencen a adquirir conciencia, conocimientos y experiencias para garantizar la utilización óptima de esta tecnología.

Microtensile bond strength of resin cements to 3-D printed and milled temporary restorative resins / Resistencia de unión en microtracción de cementos resinosos a resinas para provisionales impresas y fresadas

Abstract To evaluate the microtensile bond strength (µTBS) of two resin cements to 3D printed and milled CAD/CAM resins used for provisional fixed partial dentures. Blocks (5 x 5 x 5 mm) of three 3D-printed resins (Cosmos3DTemp / Yller; Resilab3D Temp / Wilcos and SmartPrint BioTemp, / MMTech) were printed (Photon, Anycubic Technology Co.). A milled material (VitaCAD-Temp, VITA) was used as control. Half the specimens were sandblasted and the rest were untreated. Two blocks were bonded with the corresponding resin cement: PanaviaV5 (Kuraray Noritake) and RelyX Ultimate (3M Oral Care). After 24 hours, the bonded blocks were sectioned into 1 x 1 mm side sticks. Half the beams were tested for µTBS and the other half was thermocycled (5000 cycles, 30s dwell-time, 5s transfer time) before µTBS testing. A four way Generalized Linear Model (material*sandblasting*cement*aging) analysis was applied. VITA exhibited the lowest µTBS, regardless of the cement, sandblasting and thermocycling. Sandblasting significantly improved the µTBS of VIT, especially after aging, but did not improve the µTBS of 3D printed resins. Sandblasting was not beneficial for 3D printed resins, although is crucial for adhesive cementation of milled temporary resins. Airborne particle abrasion affects the integrity of 3D-printed resins, without producing a benefit on the microtensile bond strength of these materials. However, sandblasting is crucial to achieve a high bond strength on milled temporary resins.

Resumen Evaluar la resistencia adhesiva en microtracción (µTBS) de dos cementos resinosos a resinas CAD/CAM impresas y fresadas indicadas para restauraciones provisionales. Bloques (5 x 5 x 5mm) de tres resinas impresas (Cosmos3DTemp / Yller; Resilab3D Temp / Wilcos and SmartPrint BioTemp, / MMTech) y una resina fresada (VitaCAD-Temp, VITA) fueron fabricados. La mitad de los especímenes fueron arenados y el resto no recibió tratamiento mecánico. Dos bloques con condiciones de tratamiento iguales fueron cementados con cemento resinoso (PanaviaV5 / Kuraray Noritake y RelyX Ultimate / 3M Oral Care). Después de 24 horas los bloques fueron seccionados en palitos de 1 mm² de área. En la mitad de los especímenes se midió la TBS inmediatamente y el resto fue termociclado (5000 ciclos, 30s remojo, 5s transferencia) antes de la prueba de TBS. Se aplica un análisis estadístico por Modelo Linear General con 4 factores (material*arenado*cemento*termociclado). La resina VITA presentó la menor µTBS, independientemente del cemento usado, el arenado y el termociclado. Sin embargo, el arenado aumentó la µTBS de VIT, especialmente después del termociclado. Por otro lado, el arenado no resultó en un aumento significativo de la µTBS de las resinas impresas. El arenado no fue beneficiosos para las resinas impresas, aunque es un paso crucial para la cementación adhesive de las resinas fresadas. El arenado afecta la integridad de las capas de las resinas impresas, sin generar un beneficio en la TBS.

Desafíos en el empleo de los medicamentos huérfanos

Las enfermedades raras son aquellas que tienen baja prevalencia y que, por lo tanto, el desarrollo de medicamentos para tratarlas no es rentable para las empresas farmacéuticas debido a la baja demanda. A pesar de que ya se cuenta con diferentes políticas públicas alrededor del mundo para incentivar a las industrias farmacéuticas a investigar estos medicamentos, conocidos como medicamentos huérfanos, su desarrollo conlleva muchas dificultades en las evaluaciones clínicas y el precio final para el público es muy elevado. Si bien en años recientes se ha planteado el uso de tecnología de impresión en 3D para producir estos medicamentos o incluso recurrir a otros medicamentos previamente aprobados para tratar enfermedades raras, existe un historial de mal uso de las legislaciones por parte de las empresas con el fin de generar beneficios comerciales, por lo que estas políticas deben reforzarse para que cumplan su propósito; ayudar a una población muy vulnerable. El objetivo del presente texto es exponer los resultados de una revisión documental sobre el panorama científico y sociopolítico en el que se encuentra el problema de las enfermedades raras y los medicamentos huérfanos, así como las posibles soluciones que se están desplegando para abordarlo. Deriva de un estudio que se desarrolla en el momento actual en la Universidad Autónoma Metropolitana, de Ciudad de México.

The strange illnesses are those that have low prevalence and that, therefore, the development of medications to treat them is not profitable for the pharmaceutical companies due to the drop demands. Although it is already counted with different political public around the world to motivate to the pharmaceutical industries to investigate these medications, well-known as orphan medications, their development bears many difficulties in the clinical evaluations and the final price for the public it is very high. Although in recent years he/she has thought about the use of impression technology in 3D to produce these medications or even to appeal to other medications previously approved to treat strange illnesses, a record of wrong use of the legislations exists on the part of the companies with the purpose of generating commercial benefits, for what these politicians should be reinforced so that they complete its purpose; to help a very vulnerable population. The objective of the present text is to expose the results of a documental revision on the scientific and sociopolitical panorama in which is the problem of the strange illnesses and the orphan medications, as well as the possible solutions that they are spreading to approach it. It derives of a study that is developed in the current moment in the Metropolitan Autonomous University, of Mexico City.

Anatomía de la cámara pulpar y sistema de conductos radiculares: Estrategias pedagógicas unarevisión de literatura / Anatomy of the pulp chamber and the root canal system: Pedagogical strategiesAliterature review

Antecedentes: El conocimiento anatómico de la cámara pulpar y del sistema de conductos radiculareses fundamental para el correcto diagnóstico y planificación del tratamiento en endodoncia. Las herramientas pedagógicasdirigidasa los estudiantes de odontologíacomo apoyo en los procesos formativosde la asignatura de endodoncia favorecen la apropiación del conocimiento e identificación de las variantes morfológicas del sistema de conductos radiculares, que permiten al estudiantela integración del conocimiento. Objetivo:Identificar mediante una revisión de la literatura las estrategias pedagógicas que se utilizan para la enseñanza de morfología del sistema de conductos radiculares en endodoncia. Materiales y métodos: Se realizó una búsqueda bibliográfica de estudios originales en las bases de datos Medline (Pubmed), SciELO, Lilacs, Medline (Ovid), Web of science, Scopus, Embase, Google académico, eligiendo estudios publicadosa partir del año 2010 al 2022, para la selección de los artículos definitivos se seleccionaron estudios concernientes a procesos pedagógicos en endodoncia, excluyendo así otros tipos de enfoques en el área de odontología. Resultados: Se identificaron un total de 63 referencias, los cuales fueron analizados y seleccionados16, siendo excluidos 47 por no cumplir los criterios de inclusión. Conclusión: El uso de herramientas pedagógicas virtuales, didácticas y tecnológicas propician un efecto positivo en el estudiante de pregrado de odontología durante el aprendizaje de anatomía de sistemas de conductos radiculares que aumentan la confianza y seguridad al momento de realizar un tratamiento endodóntico en pacientes

Background: Anatomical knowledge of the pulp chamber and the root canal system is essential for correct diagnosis and treatment planning in endodontics. The pedagogical tools aimed at dental students as support in the training processes of the endodontics subject favor the appropriation of knowledge and identification of the morphological variants of the root canal system, which allow the student the integration of knowledge. Objective: To identify, through a review of the literature, the pedagogical strategies used to teach morphology of the root canal system in endodontics. Materials and methods: A bibliographic search of original studies was carried out in the Medline (Pubmed), SciELO, Lilacs, Medline (Ovid), Web of Science, Scopus, Embase, and Google academic databases, choosing studies published from 2010 to 2022. , for the selection of the definitive articles, studies concerning pedagogical processes in endodontics were selected, thus excluding other types of approaches in the area of dentistry. Results: A total of 63 references were identified, 16 of which were analyzed and selected, 47 being excluded for not meeting the inclusion criteria. Conclusion: The use of virtual, didactic and technological pedagogical tools favor a positive effect on the dentistry undergraduate student while learning the anatomy of root canal systems that increase confidence and security when performing endodontic treatment in patients.

3D Printing characteristics and mechanical properties of a bio scaffold obtained from a Micro-CT Scan, using the fused deposition modeling technique

The objective is to determine which biopolymer has the best 3D printing characteristics and mechanical properties for the manufacture of a bioscaffold, using the fused deposition printing technique, with models generated from an STL file obtained from a Micro-CT scan taken from a bovine iliac crest bone structure. Through an experimental exploratory study, three study groups of the analyzed biopolymers were carried out with thirteen printed structures of each one. The first is made of 100% PLA. The second, 90B, we added 1g of diatom extract, and the third, 88C, differs from the previous one in that it also contains 1g of calcium phosphate. The 39 printed structures underwent a visual inspection test, which required the fabrication of a gold standard scaffold in resin, with greater detail and similarity to the scanned bone structure. Finally, the structures were subjected to a compressive force (N) to obtain the modulus of elasticity (MPa) and compressive strength (MPa) of each one of them. A statistically significant difference (p=0.001) was obtained in the printing properties of the biomaterial 88C, compared to 90B and pure PLA and the 88C presented the best 3D printing characteristics. In addition, it also presented the best mechanical properties compared to the other groups of materials. Although the difference between these was not statistically significant (p=0.388), in the structures of the 88C biomaterial, values of compressive strength (8,84692 MPa) and modulus of elasticity (43,23615 MPa) were similar to those of cancellous bone in the jaws could be observed. Because of this result, the 88C biomaterial has the potential to be used in the manufacture of bioscaffolds in tissue engineering.

El objetivo es determinar cuál biopolímero presenta las mejores características de impresión 3D y propiedades mecánicas para la fabricación de un bioandamiaje, utilizando la técnica de impresión por deposición fundida, con modelos generados a partir de un archivo en formato STL que se obtuvo de un Micro-CT Scan de una estructura osea de cresta iliaca bovina. Mediante un estudio exploratorio, se realizaron 3 grupos de estudio con trece estructuras impresas de cada uno. El primero, se compone 100% de PLA. El segundo, 90B, se le agrega 1g de extracto de diatomea, y el tercero, 88C, se diferencia del anterior ya que contiene además, 1g de fosfato de calcio. A las 39 estructuras impresas se les realizó una prueba de inspección visual, por lo que se requirió la confección de un patrón de oro en resina, con mayor detalle y similitud a la estructura ósea escaneada. Finalmente, las estructuras fueron sometidas a una fuerza compresiva (N) para la obtención del módulo de elasticidad (MPa) y de la resistencia compresiva (MPa) de cada una de ellas. Se obtuvo una diferencia estadísticamente significativa (p=0,001) en las propiedades de impresión del biomaterial 88C, con respecto al 90B y al PLA puro, presentando las mejores características de impresión 3D. Además, obtuvo las mejores propiedades mecánicas en comparación con los otros grupos de materiales. Aunque la diferencia entre estos no fue estadísticamente significativa (p=0,388), en las estructuras del biomaterial 88C, se pudieron observar valores de resistencia compresiva (8,84692 MPa) y módulo de elasticidad (43,23615 MPa) que son semejantes a los del hueso esponjoso de los maxilares. A razón de este resultado, el biomaterial 88C cuenta con el potencial para ser utilizado en la fabricación de bioandamiajes en la ingeniería tisular.

Randomized clinical trial on the usefulness of 3D printing in intra-articular fractures of the distal radius. / Ensayo clínico aleatorizado sobre la utilidad de la impresión 3D en las fracturas intraarticulares de radio distal.

OBJECTIVES: We evaluated the utility of 3D printing technology for preoperative planning in the treatment of intra-articular fractures of the distal radius in relation to the improvement of surgical technique, radiological and clinical results. MATERIAL AND METHODS: A total of 30 patients with 2B and C fractures of the AO classification were operated on by a single surgeon with a volar plate, randomly divided into two groups, 15 of them with conventional planning (Rx and CT) and 15 adding a 3D model of the fracture and the previous simulation of the intervention. Simulation time, surgical time in minutes, radioscopy time in minutes, loss of material expressed in lost screws were recorded. Clinical evaluation based PRWE questionnaire and full radiographic analysis was done for all patients with a mean follow-up of 6 months by an independent, blinded observed. RESULTS: No statistically significant differences were observed in the PRWE questionnaire (p=0.22), nor were we observed differences in the radiological values, except in relation to the articular step (p=0.028), which represents statistical significance, but in both groups the median was of 0.0 (0.0-0.0). We also did not see statistically significant differences in surgical times (p=0.745), radioscopy (p=0.819) or in the loss of synthesis material (p=0.779). CONCLUSIONS: 3D printing has not improved the parameters studied in relation to routinely operated patients.

Nuevos Recursos Digitales y 3D en la Enseñanza de Anatomía. Experiencia Internacional Reportada en el "Sectra Users Meeting 2019", Karolinska Institutet, Suecia, antes de la Pandemia de COVID-19 / New Digital and 3D Resources in the Teaching of Anatomy. International Experience Reported in the "Sectra Users Meeting 2019", Karolinska Institutet, Sweden, Before the Pandemic COVID-19

El uso de nuevos recursos tecnológicos en la enseñanza de anatomía ha impulsado la necesidad de adaptar el modelo educativo haciéndolo más centrado en el estudiante, dinámico y participativo mediante herramientas digitales y 3D; orientando los conocimientos hacia su aplicación clínica, pero bajo un ajuste curricular que tiende a cursar menos horas presenciales en aula o laboratorio. Este trabajo describe la experiencia local de una nueva Escuela de Medicina en Chile, reportada el año 2018, además y otros trabajos de centros formadores presentados en el "SECTRA Users Meeting 2019 Estocolmo", Karolinska Institutet, Suecia. Este trabajo describe los reportes orales sobre la aplicación de nuevos recursos digitales como; la mesa de disección digital táctil SECTRA® y modelos anatómicos cadavéricos impresos en 3D Erler-Zimmer®, bases de datos sobre anatomía digital, además, su impacto en el desempeño académico, reportado por usuarios de diferentes países, tales como: Australia, Canadá, Chile, China, Colombia, Estados Unidos de Norteamérica (EUA) y Suecia. Los datos fueron recopilados y analizados a partir de la información reportada en las presentaciones orales y resúmenes entregados por los expositores. La gran mayoría de los países expositores declararon el uso combinado de recursos digitales y 3D sumados a los tradicionales para la enseñanza de anatomía. Sólo el representante de EUA declaró usar exclusivamente recursos digitales (en laboratorio y en línea), experiencia correspondiente a una joven e innovadora escuela de medicina. La mayoría de los centros docentes declaró utilizar la mesa de disección digital en una amplia proporción de sus contenidos curriculares, en asociación a plataformas tipo RIS/PACS como IDS7 portal de SECTRA o las utilizadas por el centro formador. El uso de nuevas tecnologías digitales y 3D ha ganado un importante espacio en el currículum de la enseñanza de anatomía, complementando el uso de los recursos tradicionales.

SUMMARY: The use of new technological resources in the teaching of anatomy has promoted the need to adapt the educational model, making it more student-centered, dynamic, and participatory through digital and 3D tools, directing the knowledge towards its clinical application, but under a curricular adjustment that tends to take fewer contact hours in the classroom or laboratory. This work describes the local experience of a new School of Medicine in Chile, reported in 2018, and other work from training centers presented at the "SECTRA Users Meeting 2019 Stockholm", Karolinska Institutet, Sweden. This work describes the oral reports on the application of new digital resources such as; the SECTRA® digital tactile dissection table and Erler- Zimmer® 3D printed cadaveric anatomical models, databases on digital anatomy, in addition, its impact on academic performance, reported by users from different countries, such as Australia, Canada, Chile, China, Colombia, United States of America (USA) and Sweden. The data was collected and analyzed from the information reported in the oral presentations and summaries delivered by the speakers.The vast majority of the exhibiting countries declared the combined use of digital and 3D resources added to the traditional ones for teaching anatomy. Only the representative from the USA stated that they exclusively used digital resources (in the laboratory and online), an experience corresponding to a young and innovative medical school. Most of the educational centers stated that they used the digital dissection table in a large proportion of their curricular contents, in association with RIS/PACS-type platforms such as the IDS7 SECTRA portal or those used by the training center. The use of new digital and 3D technologies has gained an important space in the anatomy teaching curriculum, complementing the use of traditional resources.

Desenvolvimento de dentes decíduos artificiais para práticas laboratoriais em Odontopediatria / Desarrollo de dientes temporales artificiales para prácticas de laboratorio en Odontopediatría / Development of artificial primary teeth for laboratory practices in Pediatric Dentistry

Na formação em Odontologia os acadêmicos realizam treinos pré-clínicos para aperfeiçoar suas técnicas. O objetivo deste estudo é relatar a experiência de produção de dentes decíduos artificiais por impressão tridimensional (3D), com baixo custo, para práticas laboratoriais acadêmicas em Odontopediatria. Partiu-se de uma pesquisa laboratorial e experimental, tendo sido realizada uma revisão bibliográfica para obtenção dos dados. A obtenção das imagens 3D se deu a partir da biblioteca gratuita de dentes permanentes Brenner e edição no programa Meshmixer para incorporação das características de dentes decíduos, seguida de impressão 3D utilizando estereolitografia. Posteriormente, foram preenchidos os condutos radiculares com cera 7 e poliacetato de vinila (PVA)vermelha. Foi realizada também a pintura do cemento e da coroa, com tinta de esmalte marrom e branca, respectivamente. As duas resinas exibiram fidelidade anatômica externa, entretanto, para viabilidade do uso na Endodontia, foi analisada a anatomia interna, imagem radiográfica, tempo de impressão, custo de produção e custo/benefício. A combinação de resina Anycubic para a representação dos tecidos mineralizados com cera 7 para simulação da polpa possibilitou a adequada reprodução da anatomia interna de dentes decíduos (AU).

En la formación en Odontología, los alumnos realizan una formación preclínica para mejorar sus técnicas. El objetivo de este estudio es relatar la experiencia de producción de dientes temporales artificiales por impresión tridimensional (3D), a bajo costo,para prácticas académicas de laboratorio en Odontopediatría. Se inició con una investigación de laboratorio y experimental, habiéndose realizado una revisión bibliográfica para la obtención de los datos. Las imágenes 3D se obtuvieran de la biblioteca gratuita de dientes permanentes de Brenner y se editó en el programa Meshmixer para incorporar las características de los dientes temporales, seguida de una impresión 3D mediante estereolitografía. Posteriormente se obturaron los conductos radiculares con cera7 y acetato de polivinilo rojo (PVA). El cemento y la corona también se pintaron con pintura de esmalte marrón y blanco, respectivamente. Las dos resinas exhibieron fidelidad anatómica externa, sin embargo, para la factibilidad de uso en Endodoncia se analizó la anatomía interna, imagen radiográfica, tiempo de impresión, costo de producción y costo/beneficio. La combinación de la resina Anycubic para la representación de tejidos mineralizados con la cera 7 para la simulación de la pulpa permitió reproduciradecuadamente la anatomía interna de los dientes temporales (AU).

During Dentistry training, students undertake pre-clinical training to improve their techniques. The objective of this study is to report the experience of producing artificial deciduous teeth using three-dimensional (3D) printing, at low cost, for academic laboratory practices in Pediatric Dentistry. The starting point was laboratory and experimental research, and a bibliographic review was carried out to obtain data. The 3D images were obtained from the free Brenner permanent teeth library and edited in the Meshmixer program to incorporate the characteristics of deciduous teeth, followed by 3D printing using stereolithography. Subsequently, the root canals were filled with wax 7 and red polyvinyl acetate (PVA). The cementum and crown were also painted with brown and white enamel paint, respectively. The two resins exhibited external anatomical fidelity, however, for feasibility of use in Endodontics, the internal anatomy, radiographic image, printing time, production cost and cost/benefit were analyzed. The combination of Anycubic resin to represent mineralized tissues with wax 7 to simulate the pulp made it possible to adequately reproduce the internal anatomy of deciduous teeth (AU).

Biomateriales y tecnologías de impresión 3D en entrenamiento quirúrgico en otorrinolaringología: una revisión

La tecnología de fabricación aditiva o impresión 3D se ha posicionado como una herramienta transversal y de uso creciente en el mundo productivo y científico que ha otorgado la posibilidad de diseñar y crear elementos y modelos de diversa complejidad. En el área biomédica ha presentado un aumento significativo de sus aplicaciones a través del tiempo, actualmente teniendo relevancia en ámbitos como el planeamiento quirúrgico, la creación de prótesis, modelos anatómicos para educación y entrenamiento quirúrgico. Actualmente existen diversas dificultades que limitan la formación quirúrgica, especialmente en ciertas áreas de la otorrinolaringología como la cirugía de oído. El objetivo de la presente revisión narrativa fue actualizar los usos de la tecnología de impresión 3D para la creación de modelos para entrenamiento quirúrgico en otorrinolaringología, destacando sus potenciales usos en otología, rinología, cirugía de base de cráneo y vía aérea.

Additive manufacturing technology or 3D printing has positioned itself as a cross-cutting tool of increasing use in the productive and scientific world that has given the possibility of designing and creating different elements and models of varying complexity. In the biomedical area, it has presented a significant increase in its applications over time, currently having relevance in areas such as surgical planning, the creation of prostheses, anatomical models for education and surgical training. Currently there are various difficulties that limit surgical training, especially in certain areas of otorhinolaryngology such as ear surgery. The objective of this narrative review was to update the uses of 3D printing technology for the creation of models for surgical training in otorhinolaryngology, highlighting its potential uses in otology, rhinology, skull base and airway surgery.

Mechanical resistance of polylactic acid bone matrices developed by 3D printing for the reconstruction of bone defects. / Resistencia mecánica de matrices óseas de ácido poliláctico desarrolladas por impresión 3D para la reconstrucción de defectos óseos.

INTRODUCTION: Bone defects are one of the main limitations in orthopedic surgery and traumatology. For this reason, multiple bone replacement systems have been developed, either by prosthetic implant or by substitution with osteoforming substances, whose limitations are their survival and lack of structurality, respectively. The objective of this work is the generation of a new material for the creation of biologically active structures that have sufficient tensile strength to maintain the structure during remodeling. MATERIAL AND METHODS: A new filament based on the fusion of natural polylactide acid (PLA) powder was designed for the generation of pieces by means of fused deposition modeling (FDM) on which to carry out tensile mechanical tests of osteosynthesis material. A total of 13 groups with different cortical thickness, filling and layer height were carried out, with 10 tensile tests in each group, defining the tensile breaking limit for each group. The regression lines for each group and their mechanical resistance to traction on the filament used were determined. RESULTS: The filament ratio per contact surface unit with the osteosynthesis used was the main determinant of the mechanical resistance to traction, either at the expense of the increase in cortical thickness or by the increase in the percentage of cancellous bone filling. Layer height had a minor effect on tensile strength. The regression value was high for cortical thickness and cancellous filling, being elements with a predictable biomechanical behavior. CONCLUSIONS: The new methodology allows the creation of personalized neutral and implantable PLA bone matrices for the reconstruction of large bone defects by means of 3D printing by FDM with a mechanical resistance to traction greater than that of current biological support structures.

Prototyping and 3D printing of computed tomography images with an emphasis on soft tissues, especially muscles, for teaching human anatomy / Prototipado e impresión 3D de imágenes de tomografía computarizada con énfasis en los tejidos blandos, especialmente músculos, para la enseñanza de la anatomía humana

SUMMARY: The study on cadavers, although considered fundamental in the teaching of human anatomy, is limited in several universities, mainly due to the acquisition and manipulation of cadaveric material. Throughout history, several artificial anatomical models have been used to complement the real anatomical pieces. The present study offers a new alternative: the making of three-dimensional models from Computed Tomography (3D-CT) patient image acquisition. CT images from the USP University Hospital database were used. Patients underwent examinations for reasons other than the present study and were anonymized to maintain confidentiality. The CT slices obtained in thin cross-sections (approximately 1.0 mm thick) were converted into three-dimensional images by a technique named Volume Rendering for visualization of soft tissue and bone. The reconstructions were then converted to an STL (Standard Triangle Language) model and printed through two printers (LONGER LK4 Pro® and Sethi S3®), using PLA and ABS filaments. The 3D impressions of the thigh and leg muscles obtained better visual quality, being able to readily identify the local musculature. The images of the face, heart, and head bones, although easily identifiable, although seemed to present lower quality aesthetic results. This pilot study may be one of the first to perform 3D impressions of images from CT to visualize the musculature in Brazil and may become an additional tool for teaching.

El estudio en cadáveres, a pesar de considerarse un aspecto fundamental en la enseñanza de la anatomía humana, se encuentra limitado en varias universidades, principalmente por la adquisición y manipulación de material cadavérico. A lo largo de la historia se han utilizado varios modelos anatómicos artificiales para complementar las piezas anatómicas reales. El presente estudio ofrece una nueva alternativa: la elaboración de modelos tridimensionales a partir de la adquisición de imágenes de pacientes por Tomografía Computarizada (3D-CT). Se utilizaron imágenes de TC de la base de datos del Hospital Universitario de la USP. Los pacientes se sometieron a exámenes por razones distintas al presente estudio y fueron anonimizados para mantener la confidencialidad. Los cortes de TC obtenidos en secciones transversales delgadas (aproximadamente 1,0 mm de grosor) se convirtieron en imágenes tridimensionales mediante una técnica denominada Volume Rendering para la visualización de tejido blando y hueso. Luego, las reconstrucciones se convirtieron a un modelo STL (Standard Triangle Language) y se imprimieron a través de dos impresoras (LONGER LK4 Pro® y Sethi S3®), utilizando filamentos PLA y ABS. Se obtuvo una mejor calidad visual de las impresiones 3D de los músculos del muslo y la pierna, pudiendo identificar fácilmente la musculatura local. Las imágenes de la cara, el corazón y los huesos de la cabeza, aunque fácilmente identificables, parecían presentar resultados estéticos de menor calidad. Este estudio piloto puede ser uno de los primeros en realizar impresiones 3D de imágenes de TC para visualizar la musculatura y podría ser en una herramienta adicional para la enseñanza.

Prototyping and 3D printing of computed tomography images with an emphasis on soft tissues, especially muscles, for teaching human anatomy / Prototipado e impresión 3D de imágenes de tomografía computarizada con énfasis en los tejidos blandos, especialmente músculos, para la enseñanza de la anatomía humana

The study on cadavers, although considered fundamental in the teaching of human anatomy, is limited in several universities, mainly due to the acquisition and manipulation of cadaveric material. Throughout history, several artificial anatomical models have been used to complement the real anatomical pieces. The present study offers a new alternative: the making of three-dimensional models from Computed Tomography (3D-CT) patient image acquisition. CT images from the USP University Hospital database were used. Patients underwent examinations for reasons other than the present study and were anonymized to maintain confidentiality. The CT slices obtained in thin cross-sections (approximately 1.0 mm thick) were converted into three-dimensional images by a technique named Volume Rendering for visualization of soft tissue and bone. The reconstructions were then converted to an STL (Standard Triangle Language) model and printed through two printers (LONGER LK4 Pro® and Sethi S3®), using PLA and ABS filaments. The 3D impressions of the thigh and leg muscles obtained better visual quality, being able to readily identify the local musculature. The images of the face, heart, and head bones, although easily identifiable, although seemed to present lower quality aesthetic results. This pilot study may be one of the first to perform 3D impressions of images from CT to visualize the musculature in Brazil and may become an additional tool for teaching.

Uso de biomodelos impresos en 3D para la planificación preoperatoria de artroplastia total de cadera luego de fractura acetabular: reporte de un caso / 3D printed biomodels for preoperative planning of total hip arthroplasty following an acetabular fracture: a case report

Introducción. Las fracturas de acetábulo constituyen un reto para los ortopedistas por la dificultad de su tratamiento y las complicaciones asociadas.Presentación del caso. Hombre de 53 años que ingresó al servicio de urgencias de un hospital del tercer nivel de atención por policontusión en tórax y pelvis causada por un accidente de tránsito. Presentó dolor en tórax y cadera, y no se identificó lesión ósea, por lo que se dio el alta a las 48 horas. Siete días después, el paciente asistió al servicio de urgencias por dolor en la cadera izquierda y limitación para caminar. En los exámenes imagenológicos, se evidenció fractura de acetábulo izquierdo, pero fue operado luego de dos meses debido a dificultades económicas y del aseguramiento en salud. Se realizó reducción abierta más fijación interna y relleno con injerto de cresta ilíaca, y artroplastia total de cadera (ATC). A los seis meses, el paciente presentó capacidad de ambulación limitada y dolor en la cadera izquierda. Luego de los exámenes físico e imagenológico, se diagnosticó deformación severa del acetábulo izquierdo con migración posterosuperior de la cabeza femoral, necrosis de la cabeza femoral completa y defecto óseo posterosuperior de acetábulo (tipo IIIB según clasificación de Paprosky), por lo que se realizó ATC asistida por biomodelos 3D. El paciente presentó una recuperación óptima. Conclusión. Utilizar biomodelos 3D impresos optimiza la planificación preoperatoria, ya que permite reconocer la lesión, plantear el abordaje más adecuado, elegir los mejores implantes y disminuir el tiempo de operación, el sangrado y las complicaciones

Introduction: Acetabulum fractures are a challenge for orthopedic surgeons due to the difficulty of their treatment and associated complications. Case presentation: A 53-year-old man was admitted to the emergency department of a tertiary care hospital due to multiple trauma to the chest and pelvis following a traffic accident. He presented with chest and hip pain, but no bone lesion was identified, so he was discharged after 48 hours. Seven days later, the patient attended the emergency department again due to pain in the left hip and limited walking. Imaging tests showed a fracture of the left acetabulum, but he was operated on only after two months owing to economic and health insurance difficulties. Open reduction internal fixation and filling with iliac crest graft and total hip arthroplasty (THA) were performed. After six months, the patient presented limited ambulation capacity and pain in the left hip. Upon physical and imaging examinations, severe deformity of the left acetabulum with posterosuperior migration of the femoral head, necrosis of the entire femoral head, and posterosuperior bone defect of the acetabulum (type IIIB according to Paprosky's classification) were diagnosed, so 3D biomodel-assisted THA was performed. The patient had an optimal recovery.Conclusion: The use of 3D printed biomodels optimizes preoperative planning, as it allows identifying the lesion, planning the most appropriate approach, choosing the best implants, and reducing operating time, bleeding and complications

Impresión 3D de medicamentos / 3D Printing of medicines

La industria farmacéutica está en continua búsqueda de nuevas tecnologías que permitan mejorar las formas de dosificación de las que se dispone, siendo uno de los objetivos el aumento de la adherencia a los tratamientos por parte de los pacientes. En este sentido, la impresión en 3 dimensiones (3DP) es una emergente técnica de fabricación aditiva que ha comenzado a abarcar muchos sectores industriales e influir directa e indirectamente en la calidad de vida de los individuos. Tanto es así, que la 3DP se postula como una de las técnicas que podría contribuir a que se produzca un gran cambio en el sector farmacéutico, permitiendo la personalización de los tratamientos de los pacientes, mejorando la biodisponibilidad de fármacos que presentan problemas de disolución o combinando toda la medicación de un paciente en una sola forma farmacéutica de toma diaria (polypill), entre otros. Esta nueva técnica de producción va a diferir enormemente de las clásicas formas de fabricación farmacéuticas y, en los próximos años puede suponer una transformación revolucionaria en la práctica farmacéutica. (AU)

The pharmaceutical industry is continually searching for new technologies to improve the characteristics of current medicines. One of the objectives is the increase of adherence to the treatments by patients. Simultaneously, 3-dimensional printing (3DP) is an emerging additive technique that is reaching many sectors of industry and influencing directly and indirectly the quality of life of patients. In this sense, 3DP postulates to be one of the technologies that contribute to the pharmaceutical development, allowing the personalized medicine in patients, improving the bioavailability of drugs with dissolution problems or combining all the medication of the patients in a single tablet (polypill), among others. This new technique will differ greatly from the traditional pharmaceutical manufacturing and in the coming years it may involve a revolutionary transformation in pharmaceutical practice. (AU)