19 research outputs found
Simulação Em 3d Da Redução Da Fossa Posterior No Chiari Do Tipo I
We proposed a 3D model to evaluate the role of platybasia and clivus length in the development of Chiari I (CI). Using a computer aided design software, two DICOM files of a normal CT scan and MR were used to simulate different clivus lengths (CL) and also different basal angles (BA). The final posterior fossa volume (PFV) was obtained for each variation and the percentage of the volumetric change was acquired with the same method. The initial normal values of CL and BA were 35.65 mm and 112.66° respectively, with a total PFV of 209 ml. Ranging the CL from 34.65 to 29.65-24.65-19.65, there was a PFV decrease of 0.47%-1.12%-1.69%, respectively. Ranging the BA from 122.66° to 127.66°-142.66°, the PFV decreased 0.69%-3.23%, respectively. Our model highlights the importance of the basal angle and clivus length to the development of CI. © 2016, Associacao Arquivos de Neuro-Psiquiatria. All rights reserved.74540540
Multi-layered Scaffolds Production via Fused Deposition Modeling (FDM) Using an Open Source 3D Printer: Process Parameters Optimization for Dimensional Accuracy and Design Reproducibility
Abstract One of the most applied strategies in tissue engineering consists in the development of 3D porous scaffolds with similar composition to the specific tissue. In fact, the microstructure of the scaffolds influences the final structure of the in growing tissue. In this study, multi-layered PCL scaffolds were produced with modified Fab@home FDM printer in order to analyze the influence of the extrusion technology (filament or powder extrusion head) and of the process parameters on the deposited material. In particular, dimensions and uniformity of both deposited filament and grid of the scaffolds were analyzed to understand the influence of the process parameters so as to optimize the FDM production technology
Evaluation Of Degradation Of Bioabsorbable Polycaprolactone Used In Rapid Prototyping For Medical Application
Tissue engineering is an emerging field on regenerative medicine to try to solve the end-stage of organ and tissue failure. This kind of method was developed as an alternative therapy for the treatment of tissue loss or organ failure resolving the shortage on transplantation therapy. Bone and cartilage tissue are under extensive investigation in tissue engineering research. A significant progress has been done on the recent years, although one major obstacle is to maintain the constructed tissue alive in vitro as well as in vivo. For this kind of problem a large number of bioresorbable materials and scaffolds design have been developed. They must have some especial characteristics such as three-dimensional features and highly porous structure with interconnection, biocompatibility and degradation control. Additionally, they shall present suitable surface for attachment of cells, growth and differentiation. Trying to enhance these properties it was used a bioabsorbable polymer approved by the FDA, polycaprolactone. Selective Laser Sintering (SLS) was used with a deflected laser beam selectively to scan over the powder surface following the cross-sequential profiles carried by the slice data. The interaction of the laser beam with the powder elevates the powder temperature to reach the glass-transition temperature, causing surfaces in contact to deform and fuse together. CAD models of different scaffolds were made to evaluate the most commons problems such shrinkage and distortion. In this case we observed oversize of the scaffold walls, reducing the pores size. To evaluate the material degradation rate it was used the SBF solution on 37°C on different times of immersion. After that the samples were weighted and observed on the SEM. We could see a reduction of mass percentage and it was visible bulk degradation of the material on the microscope observation. This study allows some properties of bioabsorbable polymer used in rapid prototyping (SLS), but it must be done citotoxicity tests to evaluate the biocompatibility. © 2008 Taylor & Francis Group.101105Berry, E., Preliminary experience with medical applications of rapid prototyping by selective laser sintering (1997) Med Eng Phys, 19 (1), pp. 90-96Bezwada, R.S., Monocryl suture, a new ultrapliable absorbable monofilament suture (1995) Biomaterials, 16, pp. 1141-1148(2007) InVesalius software, , http://www.cenpra.gov.br, CenPRA , Available atChen, D.R., Polycaprolactone microparticles and their biodegradation (2000) Polymer Degradation and Stability, 67, pp. 455-459Chen, J.H., (1995) Polym Mater Sci Eng, 11, p. 79Darney, P.D., Clinical evaluation of the Capronor contraceptive implant: Preliminary report (1989) Am J Obstet Gynecol, 160, pp. 1292-1295Das, S., Freeform fabrication of nylon-6 tissue engineering scaffolds (2003) Rapid Prototyping J, 9 (1), pp. 43-49Deckard, C.R., (1986) Generation by Layerwise Selective Sintering, , MS thesis, Department of Mechanical Engineering, University of Texas at AustinDeckard, C.R., (1988) Selective Laser Sintering, , PhD dissertation, Department of Mechanical Engineering, University of Texas at AustinDeshpande, A.A., Bioerodible polymers for ocular drug delivery (1998) Crit Rev Therapeutic Drug Carrier Systems, 15 (4), pp. 381-420Engelberg, I., Kohn, J., Physicomechanical properties of degradable polymers used in medical applications:a comparative study (1991) Biomaterials, 12 (3), pp. 292-304Li, Y., Effects of filtration seeding on cell density, spatial distribution and proliferation in nonwoven fibrous matrices (2001) Biotechnol. Prog, 17, pp. 935-944Pitt, C.G., Schindler, A., Biodegradation of polymers (1983) Controlled drug delivery, pp. 55-80. , Bruck SD, editor, Boca Raton, FL: CRC Press. pSanchlos, E., Czernuzka, J.T., Making Tissue Engineering Scaffolds Work: Review on the Application of Solid Free-form Fabrication Technology to the Production of Tissue Engineering Scaffolds (2003) European Cells and Materials, 5, pp. 29-40Shishkovsky, I.V., The synthesis of a biocomposite based on nickel titanium and hydroxyapatite under selective laser sintering conditions (2001) Techn Phys Lett, 27 (3), pp. 211-213Suggs, L.J., Mikos, A.G., Synthetic biodegradable polymers for medical applications (1996) Physical properties of polymers handbook, pp. 615-624. , Mark JE, editor, New York: American Institute of Physics. pTan, K.H., Scaffold development using selective laser sintering of polyetheretherketone-hydroxyapatite biocomposite blends (2003) Biomaterials, 24 (18), pp. 3115-3123Vail, N.K., Materials for biomedical applications (1999) Mater Design, 20 (2-3), pp. 123-132Willians, J.M., Bone tissue engineering using polycaprolactone scaffolds fabricated via selective laser sintering (2005) Biomaterials, 26, pp. 4817-4827Wiria, F.E., (2007) Poly-e-caprolactone/hydroxyapatite for tissue engineering scaffold fabrication via selective laser sintering Acta Biomaterialia, 3, pp. 1-12Yeong, W.Y., Rapid prototyping in tissue engineering: Challenges and potential (2004) Trends in Biotechnology, 22 (12), pp. 643-652Zein, I., Fused deposition modeling of novel scaffold architectures for tissue engineering applications (2002) Biomaterials, 23, pp. 1169-118
FEM analysis on forming, springback and residual stress of titanium plates for mandible reconstruction-Case study
Use Of Rapid Prototype Techniques For Large Prosthetic Cranioplasty
This work describes a set of procedures for the creation of a prosthetic 3D geometry based on virtual modeling from medical images. This technique uses engineeringCADtools and rapid prototype systemsto create the best shape structure for filling a bone gap - cranioplasty - in a patient involved in a car accident.This application shows an engineering solution to create a prosthetic cranioplastic device according to the following procedures: creation of a virtual model using CAD systems; creation of physical model for the surgical planning using rapid prototype techniques; creation of moulds for the end model using rapid prototype techniques; and, finally, the creation of a prosthetic device using the appropriate biomaterial. © 2012 Taylor & Francis Group, London.767769Cabraja, M., Klein, M., Lehmann, T.N., Longterm results following titanium cranioplasty of large skull defects (2009) Neurosurg Focus, 26 (6), pp. E10. , 2009Jagannathan, J., David, O., Okonkwo, D.O., Dumont, A.S., Ahmed, H., Bahari, A., Prevedello, D.M., Jane Jr., J.A., Outcome following decompressive craniectomy in children with severe traumatic brain injury: A 10-year single-center experience with long-term follow up (2007) J Neurosurg, 106 (4 SUPPL.), pp. 268-275. , 2007Salmi, M., (2009) Design and Rapid Manufacturing of Patient-Specific Implants, , Master's Thesis, Helsinki University of Technology, Faculty of Engineerin
Comparison Of Five Rapid Prototype Techniques (sls/fdm/dlp/3dp/polyjet)
The rapid prototyping technology is an effective tool in making models for use in medical applications. This paper proposes the study of rapid prototyping processes through the analysis of the technical features measuring a standard model. The processes evaluated are SLS (Selective Laser Sintering), FDM (Fused Deposition Modeling), DLP (Digital Light Processor), PolyJet and 3DP (Tridimensional Printer). This article aims to describe the characteristics of materials used in these processes, such as roughness, hardness, surface finish and dimensional analysis (using scanning inspection). This study also brings a brief description of the concepts involved in each process and what parameters should be observed during processing. © 2012 Taylor & Francis Group, London.573580Chua, K., Leong, K.F., Lim, C.S., (2010) Rapid Prototyping: Principles and Applications, p. 512. , 3rd Edition. Singapore: World Scientific Publishing Co. Pte. Ltd., 2010Souza, A.F., Ulbrich, C.B.L., (2009) Engenharia Integrada Por Computador e Sistemas CAD/CAM/CNC - Princípios e Aplicações, p. 332. , São Paulo: EditoraArtliber Ltda, 2009Volpato, N., (2007) Prototipagem Rapida: Tecnologias e Aplicações, p. 244. , São Paulo: Edgard Blucher, 2007Wohlers, T., (2008) Wohlers Report 2008, , State of the Industry, AnnualWorldwide Progress Repor
The Virtual Biomodel As A Complementary Resource For The Diagnosis Of Mandibular Ankylosis
Ankylosis of the mandibular joint is one of many pathologies that affect the temporomanbibular joint. It comprises the mandible condyle, the base of the skull bone and the joint itself, inducing changes in the skull bone and face complex, affecting their growth to different degrees, which can cause morphofunctional alterations. The objective of this paper is to show the gains of using a virtual biomodel as an additional resource in the diagnosis of mandibular joint ankylosis, besides the analysis of multiplanar slices.24225228Casanova, M.S., Tuji, F.M., Ortega, A.I., Yoo, H.J., Haiter-Neto, F., Computed tomographyof the TMJ in diagnosis of ankylosis: Two case reports (2006) Oral Med. Pathol, E4, pp. 13-16Cevidanes, L.H.S., Styner, M.A., Proffit, W.R., Image analysis and superimposition of 3-dimensional cone-beam computed tomography models (2006) American Journal of Orthodontics and Dentofacial Orthopedics, 129 (5), pp. 611-618Güven, O., A clinical study on temporomandibular joint ankylosis (2000) Auris Nasus Larynx Int. J. ORL & HNS, 27, pp. 27-33Jureyda, S., Shucard, D.W., Obstructive sleep apnea, an overview of the disorder and its consequences (2004) Seminars in Orthodontics, 10 (1), pp. 63-72Ko, E.W.-C., Huang, C.-S., Chen, Y.-R., Temporomandibular joint reconstruction in children using costochondral grafts (1999) J. Oral Maxilofac. Surg, 57, pp. 789-798Manganello-Souza, L.C., Mariani, P.B., Temporomandibular joint ankylosis: Report of 14 cases (2003) Int. J. Oral Maxillofac. Surg, 32, pp. 24-29Martins, T.A.C.P., Santa Bárbara, A., Silva, G.B., Faria, T.V., Cassaro, B., Silva, J.V.L., InVesalius: Three-dimensional medical reconstruction software (2008) Proceedings of the 3rd International Conference on Advanced Research in Virtual and Rapid Prototyping, pp. 135-141Oliveira Jr, P.A., Pires, L.F.S., Oliveira, G.S., Faber, P.A., Temporomandibular joint ankylosis after condylar fracture with penetration of the condyle in the medium cranial fossa (2005) Journal of Oral and Maxillofacial Surgery, 63 (12), pp. 1778-1781Preston, C.B., Lampasso, J.D., Tobias, P.V., Cephalometric evaluation and measurement of the upper airway (2004) Seminars in Orthodontics, 10 (1), pp. 3-15Preston, C.B., Tobias, P.V., Salem, O.H., Skeletal age and growth of the nasopharynx in the sagital plane: A cephalometric study (2004) Seminars in Orthodontics, 10 (1), pp. 16-38Sales, M.A.O., Oliveira, J.X., Cavalcanti, M.G.P., Computed tomography imaging findings of simultaneous bifid mandibular condyle and temporomandibular joint ankylosis: Case report (2007) Brazilan Dental Journal, 18 (1), pp. 74-77Singh, D.J., Bartlett, S.P., Congenital mandibular hypplasia: Analysis and classification (2003) J Craniofacial Surg, 16 (2), pp. 291-30
Phb Obtained By Selective Laser Sintering For Bone Tissue Engineering
[No abstract available]31556Shishatskaya, E.I., (2004) J Mater Sci Mater Med, 15, p. 719Volova, T., (2003) Biochemical Eng J, 16, p. 125Lucchesi, C., (2007) J Mater Sci Mater Med, p. 10Davies, J.E., (1999) Bone Engineering: Based on the Proceeding of the Bone Engineering Workshop Held in Toronto, , Hong Kong, Rainbow Graphic and Printin