Biomecánica del pilar canino en el cráneo humano basada en la geometría utilizando análisis de elementos finitos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)This study evaluated the stress distribution based on the canine pillar geometry in human skull, using a finite element analysis. Computed tomography of human skull was used to build a finite element model, which was composed by all bony structures of canine pillar: canine eminence, canine fossa, frontal process of maxilla, glabellum and superciliary arch. A support on the bite contact of maxillary canine tooth and a resultant force of the masticatory muscles was applied in the simulation. Equivalent Von-mises and maximum principal stresses were analyzed along the structures that compose the canine pillar geometry. Von-mises stress presented high stress concentrated at the canine fossa and frontal process of maxilla. Maximum principal stress showed compression areas at the canine fossa and part of frontal process and tensile stress at canine eminence and part of the frontal process. In conclusion, the different stress areas means different force concentrations transmitted along the canine pillar geometry during a peak canine bite.This study evaluated the stress distribution based on the canine pillar geometry in human skull, using a finite element analysis. Computed tomography of human skull was used to build a finite element model, which was composed by all bony structures of can321214220CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)sem informaçãoEste estudio evaluó la distribución de la tensión sobre la geometría del pilar canino en el cráneo humano, utilizando análisis de elementos finitos. Se usó la tomografía computarizada de cráneo humano para construir un modelo de elementos finitos compuestBrazil for financial support and the Center for Information Technology “Renato Archer” (Campinas, Brazil) for technical and scientific suppor

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

Porous Titanium implants: in vivo and in vitro preliminary bone ingrowths analysis

Among various metallic biomaterials, titanium and its alloys are the most interesting for orthopaedic implants due to their excellent mechanical properties, biocompatibility and good corrosion resistance. However, a major problem concerning metallic implants in orthopaedic surgery is the mismatch of Young’s modulus between natural bone and bulk metallic biomaterials. Owing to this mechanical mismatch, bone is insufficiently loaded and becomes stress shielded, which can lead to bone density reduction and eventual loosening of the implant. Moreover vascularisation problems could occur due to the implant structure. A suggestion to overcome these drawbacks could be the design of porous materials, characterized by a Young’s modulus close to the natural bone, that could help the vascularisation inside the bone. In this work a preliminary in vitro and in vivo analysis was designed in order to investigate the cell growing on the boundary and on the bulk of new implants characterized by an interconnected porosity. Promising results were achieved for both analysis

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

Bridging Plate Development For Treatment Of Segmental Bone Defects Of The Canine Mandible: Mechanical Tests And Finite Element Method

With regard to the canine mandible, a mistaken concept of application is to assume that systemic plate-bone resistance is provided by the implant so that biomechanical position could be ignored. Because the alveolar border of the mandible is a tensile zone, the plate would ideally be positioned near this area while avoiding important structures. The aim of this study was to develop 2 bridging plates for the treatment of a segmental bone defect of the canine mandible using monocortical screws to avoid damage to the tooth roots and remaining neurovascular structures. Computed tomography images of the heads of 4 dogs (rottweiler, Doberman, boxer, and miniature poodle breeds) were used as models to develop the project. The images were reconstructed in 3-dimensional (3D) format. For each dog breed, 6 mandible prototypes were produced, each with a segmental bone defect in the right mandible. The mandibular reconstruction was performed with pure titanium bridging plate and locking screws. One plate model was developed for medium- and large-breed dogs and another for small-breed dogs. Mechanical testing showed the platemandible system resists the bite forces in all dog breeds. All safety factors were greater than 1 in the platemandible system for medium- and large-breed dogs and greater than 10 in the plate-mandible system for small-breed dogs. Thus, bridging plates designed with differentiated geometry and monocortical locking screws showed mechanical resistance to support simulated induced bone model defects and were able to support at least 5 times the value of bite force for each evaluated dog. © The Author(s) 2016.331182