Validación de un modelo simulado inanimado basado en impresión 3D de ureterorrenoscopía flexible / Validation of an inanimate simulated model based on flexible ureterorenoscopy 3D printing

Resumen Objetivo: Establecer validez aparente, de contenido y constructo, de un programa de simulación de ureterorrenoscopía flexible. Materiales y Método: Se desarrolló un modelo de simulación de silicona para ureterorrenoscopía flexible, en el cual se establecieron 8 marcas de colores en los distintos cálices. Para la validación, se reclutaron urólogos expertos y residentes de urología con experiencia variable en este procedimiento. Se separaron en 3 grupos: G1 para residentes sin experiencia en ureteroscopía, G2 para residentes con experiencia variable y G3 para urólogos expertos. Se les solicitó realizar una navegación completa del modelo, en un tiempo máximo de 600 segundos. Al finalizar, cada participante contestó una encuesta respecto a la utilidad y realismo del modelo. Además, se midió tiempo total, número de puntos encontrados y cantidad de veces de reingreso a los cálices para validación de constructo. Resultados: 15 personas participaron en la evaluación. Se obtuvo una mediana de 8,6 puntos para la utilidad del modelo y 6,75 puntos para el realismo de este. Los tiempos totales de navegación fueron 504, 293 y 133 segundos para G1, G2 y G3 respectivamente (p = 0,02). De las 8 marcas, se encontraron en promedio 5,1, 6,6 y 7,3 (p = 0,18), presentando un promedio de 9,5, 3,8 y 1,3 reintentos de exploración de los cálices en los respectivos grupos (p = 0,11). Conclusiones: Se establece validez aparente y contenido para un modelo de ureterorrenoscopía flexible. El programa de simulación de ureterorrenoscopía flexible establecido, permite diferenciar novatos de expertos en cuanto a reducción en los tiempos de navegación.

Aim: To establish the face, content, and construction validity of a flexible ureterorenoscopy simulation program. Materials and Method: A simulation model for flexible ureterorenoscopy was developed using silicone on which eight colored marks were marked on the calyxes. For validation, expert urologists and residents with varying amounts of experience in this procedure were recruited. They were separated into three groups: 1) G1 for residents without experience in ureteroscopy; 2) G2 for residents with variable experience; and 3) G3 for expert urologists. They were asked to perform a full navigation of the model in a maximum time of 600 sec. At the end, each participant answered a survey regarding the usefulness and realistic nature of the model. In addition, total time, number of marks found, and times of re-entry to the calyxes were measured. Results: A median of 8.6 points was obtained for the utility of the model and 6.75 points for its realistic nature. The total navigation times were 504, 293, and 133 seconds for G1, G2, and G3, respectively (p = 0.02). Of the eight marks, an average of 5.1, 6.6, and 7.3, (p = 0.18) were found with an average of 9.5, 3.8, and 1.3 exploration reattempts at the chalices in the corresponding groups (p = 0.11). Conclusions: Face and content validity was established for this simulation model of flexible ureterorenoscopy. This flexible ureterorenoscopy simulation program allowed us to differentiate the level of expertise in terms of reduction in navigation time.

Accuracy of dental models fabricated by CAD/CAM milling method and 3D printing method

The purpose of this study was to evaluate the accuracy of a dental model fabricated using the CAD/CAM milling method and the 3D printing method. materials and method: this study was conducted in sequence of the digitization of the master model using an intraoral scanner, the manufacturing of working models (milling model, Multi-jet printing model and color-jet printing model) by using the scan data of the master model, the digitization of the working model by using a laboratory scanner, the superimposition of the digital data of the master model and working models using inspection software, and 3-dimensional analysis. ten measurements per group were done by one practitioner. one-way ANOVA and Tukey's post-hoc test were performed to compare the difference between the three groups. results: the overall difference in models caused by the manufacturing method was measured as 73.05µm±9.64µm, 84.52µm±4.78µm, and 96.05µm±5.43µm in the milling group, multi-jet printing group and color-jet printing group, respectively. the difference according to the shape of the teeth, the abutment teeth among the three parts was recorded with the lowest values as 19.18±2.08µm, 77.10±7.48µm, and 56.63±4.58µm. conclusions: dental models manufactured by the CAD/CAM milling method presented superior accuracy over the models manufactured by the 3D printing method. therefore, the use of optimized CAD software and appropriate materials is crucial for the fabrication accuracy of dental models.

Caso Clínico: Uso de Biomodelos Tridimensionales para la Planificación Preoperatoria de Tumores Craneales Fronto - orbitarios / Case Report: Use of Tridimensional Biomodels for Surgical Planning in Fronto-orbital Bone Tumors

INTRODUCCIÓN: La impresión tridimensional de biomodelos ha demostrado en los últimos años ser de gran utilidad para el diagnóstico, tratamiento y planificación preoperatoria en prácticamente todas las especialidades quirúrgicas. En este reporte se presenta la experiencia inicial con el empleo de biomodelos tridimensionales, para la planificación pre quirúrgica de un paciente con displasia fibrosa fronto-orbitaria operado en Cuenca, Ecuador. CASO CLÍNICO: Paciente de sexo masculino de 11 años de edad que desde hace 4 años presentó una¿ masa frontal derecha dura, inmóvil, no dolorosa, de crecimiento progresivo, que produjo deformidad orbitaria con exoftalmia e hipotropia. La tomografía craneal demostró una lesión ósea de núcleo hipodenso, de 5 cm de diámetro mayor, con compromiso del techo de la órbita, porción lateral del seno paranasal frontal y extensión intracraneal extradural. EVOLUCIÓN: Para planificar la cirugía se elaboró un modelo óseo tridimensional que se usó para explicar al paciente y sus padres el objetivo del procedimiento y como se realizaría. El día de la intervención, se dibujaron las osteotomías y craneotomía en el modelo anatómico, plan que se aplicó exactamente en el paciente. El postoperatorio transcurrió sin novedades, la tomografía computarizada de control evidenció una resección completa de la lesión y una adecuada reconstrucción orbitaria. El paciente y sus familiares se mostraron muy satisfechos con las explicaciones dadas. CONCLUSIONES: La impresión 3D es una herramienta que cada vez gana más espacio en la docencia y también en la planificación quirúrgica pues permite disponer de modelos anatómicos muy precisos y simular el procedimiento operatorio, antes de realizar el procedimiento en el paciente real. (AU)

BACKGROUND: 3Dprinting of biomodels has shown in recent years to be very useful for diagnosis,treatmentandpreoperativeplanninginpracticallyall surgical specialties. Inthis reportispresentedthe initial experiencewiththeuseoftridimensionalbiomodels,forpre-surgicalplanninginapatientwithfronto-orbital fibrous dysplasia operated in Cuenca, Ecuador. CASE REPORT: An 11 years old boy presented with a 4-year history of a slow-growing, hard, non-mobile, painless rightfrontalmass which caused orbital deformity, proptosis, and hypotropia. Cranial Computer Tomography showed a 5 cm bone tumor with hypodense center compromising the orbital roof and the lateral aspect ofthe frontal paranasal sinus with intracranial extradural expansion. EVOLUTION: To design the surgery, a tridimensional bone model was elaborated and used to explain the patient and his parents the aim of the procedure and how it will be performed. The day of the intervention, the osteotomies and craniotomy were drawn on the anatomical model, plan that was exactly applied to the patient. The postoperative period was uneventful, control CT scan showed a complete resection of the lesion and an adequate orbital reconstruction. The patient and his relatives were very satisfied with the explanations given. CONCLUSIONS: 3D printing is a very useful surgical tool with wide applications in planning and education that allows simulate in very accurate biomodels an operative procedure before it was done in the actual patient(AU)

Bioimpressão e produção de mini-órgãos com células tronco / Bioprinting with stem cells and production of mini-organs

A bioimpressão é considerada uma fonte promissora no desenvolvimento celular, e na produção de mini-órgãos, válulas, cartilagens que futuramente poderão ser utilizados na terapia para transplantes em animais e humanos. Assim, essa técnica poderá ser utilizada como uma terapia eletiva, no tratamento de injúrias e principalmente no tratamento de doenças crônico-degenerativas. Em humanos essa terapia está sendo pesquisada a fim de auxiliar a medicina no tratamento e regeneração de tecidos impressos a partir de arcabouços de células desenvolvidas a partir de células-tronco, biomateriais e impressões em 3D. O uso dessa tecnologia é também um auxiliar nas pesquisas oncológicas com o intuito de projetar e avaliar a proliferação celular de tumores, bem como a ação de novos medicamentos quimioterápicos. No entanto, a maior limitação para o uso da terapia utilizando-se a impressora de células, órgãos e tecidos em 3D é a falta de protocolos unificados com metodologias reprodutíveis e detalhadas; com o objetivo de viabilizar a utilização da impressora e a impressão de células, órgãos e tecidos em 3D. Dessa forma, esta revisão busca reunir as publicações mais atuais na área, as quais destacam os avanços no uso de bioimpressão com células-tronco, a fim de descrever as principais técnicas e os potenciais de utilização como alternativa terapêutica na medicina humana e veterinária.(AU)

The bioprinting is considered a promising source in cell development, and production of mini-organs, valves, cartilage that may eventually be used in therapy for transplantation in animals and humans. It can also be used as an elective therapy in the treatment of injuries and treatment of chronic degenerative diseases. In humans, this therapy is been studied mainly in the treatment and regeneration of tissues printed from scaffold cells developed from stem cells, biomaterials and impressions in 3D. This technology is also an aid for the study of the formation of tumors, in order to design and evaluate the cellular proliferation of the tumors and the action of new chemotherapy drugs. However, the main drawback to this therapy is the lack of standardized protocols with reproducible and detailed methodologies with the aim of enabling the use of bioprinting and printing cells, tissues and organs in 3D. Thus, this review seeks to bring together the most current publications of the bioprinting area in order to describe the technique and its potential use as a therapeutic alternative.(AU)

Aplicações da impressão 3D na Ortodontia e Cirurgia bucomaxilofacial / Applications of 3D printing technology in Orthodontics and Oral and Maxillofacial Surgery

Ao longo da última década, avanços na prototipagem rápida vêm acontecendo, resultando no desenvolvimento de novas técnicas e abordagens. É o resultado de tecnologias de fabricação em 3D, como a estereolitografia (SLA), modelagem fundida (FDM) e, mais recentemente, a sinterização seletiva a laser (SLS). Entre suas aplicações, os guias cirúrgicos são gerados via computador e posteriormente fabricados por uma impressora 3D, sendo utilizado durante a cirurgia, possibilitando assim, posicionar de forma precisa os segmentos ósseos. A prototipagem também pode ser usada associada à tecnologia CAD/CAM (desenho assistido por computador) na Ortodontia, para personalizar a posição de braquetes e preparar guias personalizados para colagem ortodôntica indireta. Também, pode ser aplicada na customização e fabricação da aparatologia ortodôntica, através da fusão de imagens de modelos 3D. É notório que cada vez mais a prototipagem rápida vai se tornar uma rotina no dia a dia do ortodontista e do cirurgião, pois facilitam sobremaneira os procedimentos clínicos e possibilitam ao profissional ter maior previsibilidade dos seus resultados.

During the last decade, advances in rapid prototyping have resulted in the development of new techniques and approaches including 3D manufacturing technologies such as stereolithography (SLA), molten modeling (FDM), and more recently, selective laser sintering (SLS). Among its applications, the surgical guides are computer-generated, and then manufactured by a 3D printer for use during surgery, thus enabling precisely positioning of bone segments. Prototyping can be also used with CAD/CAM technology (computer aided design) in orthodontic brackets to customize its position and prepare customized guides for indirect orthodontic bonding. It’s also applied for customization and manufacturing of orthodontic appliance by the 3D model image fusion. It is clear that rapid prototyping will become a routine for the orthodontist and surgeon. It will facilitate the clinical procedures in such a way that professionals with have more predictable outcomes.