|
|
Research study of mandible fracture reconstructions from a biomechanical standpoint
Semerák, Jaroslav ; Florian, Zdeněk (referee) ; Marcián, Petr (advisor)
This thesis deals with the treatment of mandibular fractures using splints and fixators. The topic was the development of a detailed research study based on available literature. The work also indicates basic anatomy of the surveyed area and nowadays the most commonly used materials. Then, the stress-strain analysis of the system broken mandible with angular stable fixation was performed. Stress-strain analysis solution was realized by computational modeling, in use of the finite element method in Ansys Workbench 16.2. The work is described in detail the creation of computational model system and its subsequent solutions.
|
|
|
Stress - strain analysis of jaw with decrease bone tissue
Krpalek, David ; Fuis, Vladimír (referee) ; Florian, Zdeněk (advisor)
This diploma thesis deals with stress - strain analysis of jaw with decrease of bone tis-sue. At first was created a model of geometry using graphic program Rhinoceros 4.0 upon acquisition by the 3D scanner. That was converted to the computational system ANSYS Workbench 11 which uses for solving the finite element method (FEM). Solving was executed with homogenous, linear and isotropic material model of bone with different characteristics for compact and cancellous bone. Forces of the three working muscles, which participate on chewing, were given on the basis of the force and moment balance mandible. Solving was executed for 12 variant simulating occlusion in places, where was earlier found teeth.
|
|
|
Stress-strain analysis of mandible with applied fixator due to the missing bone tissue
Fňukal, Jan ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This thesis deals with the fixation of lower jaw with bone tissue defect using commercially produced fixator. Large defects of bone tissue are mainly caused due to the removal of bone tissue affected by tumor. These topics have been researched on the basis of the literature. Subsequently, stress strain analysis of the lower jaw with the applied fixation plate was performed. This analysis was solved by using computational modeling with variational approach, ie the finite element method. The work also describes in detail the procedure of creating model of geometry, model of material, model of boundary conditions and loads with subsequent solution of several computational models. The stress strain analysis was done for lower jaw with varying size of the removed bone tissue with applied reconstruction plate made of CP-Ti Grade 4 and for the lower jaw with the plate, which is made of -Ti-Mo. Finally, the influence of the mechanical properties of the callus during formation of new bone tissue (callus healing) on the stress and deformation of the solved system was evaluated.
|
|
|
Biomechanical Studies of Facial Bone
Valášek, Jiří ; Janíček, Přemysl (referee) ; Horyl, Petr (referee) ; Florian, Zdeněk (advisor)
Presented work deals with Biomechanical study of the facial skeleton. This work is focused on the fixation of the mandible after removal of a tumor from affected bone tissue. The aim of the work is to perform biomechanical study of the facial skeleton with subsequent detailed stress strain analysis of two mandible implants designed and manufactured for specific patients. The geometry model of mandible used for design of mandible implants and used for computational modelling has been obtained on the basis of CT data of two patients. A Theoretical-Clinical sub-study that deals with the comparison the CT data processing which is necessary for creating the model of geometry is a part of the thesis. Two models of mandible with applied mandible implant have been created for two specific patients with tumorous mandible bone tissue. Stress strain analysis has been performed for these two models. Results of the stress strain analysis of two models of mandibles with mandible implants are presented in the final chapters of the thesis. Findings of the biomechanical study have been published and applied in clinical practice.
|
|
|
Research study of total endoprosthesis of temporomandibular joint
Horňas, Jan ; Borák, Libor (referee) ; Marcián, Petr (advisor)
This bachelor’s thesis deals with total joint replacements (TJR) applied for replacement of temporomandibular joint (TMJ). In the thesis, research study of solutions system is done for anatomy of TMJ, mandible and masticatory muscles. Main producers and ma-terials for manufacturing TJR is mentioned furthermore. Finally, stress strain analysis for TJR is done by computing modeling using finite element method on the basis of re-search study.
|
|
|
Biomechanical Study of Tooth Implants for Low Density Bone
Marcián, Petr ; Janíček, Přemysl (referee) ; Horyl, Petr (referee) ; Florian, Zdeněk (advisor)
This work deals with problem of dental implant area, where there are many problems at the dental implants application. The essential issue is the bone tissue quality at implant application, which sig-nificantly influences its deformation, tension and the possibility of subsequent implant failure. The knowledge of bone tissue mechanical properties of mandible and mandible with applied implant can significantly affect prediction of dental implant failure. The mechanical interaction can be described by variable determining deformation and tension of solved system. For this reason the computational modeling by using Finite Element Method was used for solving given problem. The computational model creation of solved system on the high resolution level is necessary for biomechanical assessment of implant failure, including bone tissue quality. For this purpose the biomechanical study was performed, which significantly spreads range of solved problem in this work afterwards. In this work the methodology, which describes assessment of bone tissue quality where the implant should be applied as well as mutual interaction, is presented. The results confirm necessity of bone tissue computational models creation on high resolution level including complex trabecular architecture. In this work the creation of trabecular structure computational model from data gained on micro-CT device is described. Further, the trabecular structure computational model was created on the 3D level with dental implant and the stress strain analysis was performed consequently. The last part of this work deals with introductory study of bone tissue modeling and remodeling.
|
|
|
Stress-Strain Analysis of Total Endoprosthesis of Temporomandibular Joint
Horňas, Jan ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
The presented master’s thesis deals with the problem of the application of total endoprosthesis (TEP) during temporomandibular joint (TMJ) replacement. The implantation of TEP occurs due the severe TMJ disease (arthrosis, ankylosis, cancer) or its macrotrauma. Condylar prosthesis is fixed during the implantation by self-tapping screws to the mandible. This fixation causes a change of stress-strain behaviour of mandible, TEP and fixation screws. In the thesis is performed the stress-strain analysis by using computational modeling in use the finite element method (FEM). Analysis is performed for six different screws positions (the number of screws is unchanged) and for a variable the static friction coefficient (in range 0.1 to 0.11) between condylar prosthesis (CP) and fossa prosthesis (FP). Altogether, 36 variants of computational models were created. The stress strain analysis detected a substantial influence of the static friction coefficient value to final results of displacements, contact pressure on the articulation surface between the CP and the FP and also to von Mises stress of the CP. A substantial influence of different screws position is detected for von Mises stress in the screws and for von Mises strain in the cortical and spongious bone tissue.
|
|
|
Stress-Strain Analysis of Mandible with Fixator
Semerák, Jaroslav ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This diploma thesis deals with fixation of the lower jaw fractures using commercially produced fixators. The topic was researched on the basis of the available literature. The thesis also indicates basic anatomy of the surveyed area and nowadays the most commonly used materials. Subsequently, the stress-strain analysis of the lower jaw with the applied angular stable fixation plate was performed. The solution was performed for the lower jaw with a fracture in the area of the condyle with different types of fixation plates made of CP-Ti Grade 4. In addition, the strain analysis of the healed lower jaw with the fixators after the defect in the area of chin and angle was performed. The mechanical interaction analysis of the lower jaw with defect and applied fixation plate was solved by using computational modeling with variational approach, in use of the finite element method in Ansys Workbench 18.1. The thesis also describes in detail the creation of a computational model of the system and the subsequent solution.
|
|
|
Stress-strain analysis of dental implant inserted in different mandibles
Diakovová, Tereza ; Thomková, Barbora (referee) ; Marcián, Petr (advisor)
This thesis deals with a problem in the field of dental implantology, namely the mechanical interaction between the dental implant and the bone tissue of the mandible. This interaction is affected by the shape and density of the bone tissues. A review of studies dealing with mechanical stresses at the bone-implant interface is carried out. The obtained information were further used in the analysis of bone tissue density and in the strain-stress analysis of three geometrically different jaws with an implant placed in the first molar region. Bone density was evaluated based on information obtained from CT scans of the individual jaws. For evaluation of the deformation-stress states was used computational modelling using the finite element method. Three models of jaw geometries were created based on CT images. The implant was loaded from masticatory forces at the moment of bite. Based on the results, it can be stated that the shape and thickness of the cortical bone tissue and the density of spongiosis have a significant influence on the deformation-stress states of the bone-implant interface.
|
|
|
Evaluation of ontogenetic development of the mandible using geometric morphometric methods
Kiebelová, Alena ; Velemínská, Jana (advisor) ; Brůžek, Jaroslav (referee)
During ontogeny there are a lot of changes in the entire human skeleton. This thesis deals with shape changes in the mandible, which are caused by genetic, hormonal, as well as mechanical factors. The most important mechanical factors influencing the shape of mandible are development of deciduous and permanent dentition and also development of masticatory muscles. 34 children mandibles of known age and 14 adult mandibles were analysed and compared for this thesis. Data were obtained by scanning coordinates of 36 landmarks using Microscribe G2X, and then were processed by software PAST and Morphologika2 using multivariate statistics (PCA, MANOVA). Geometric morphometrics is used for a detailed analysis of shape changes of the mandible. There is no difference between dental and chronological age. In conclusion, lower jaw narrows during growth, the body extends more in the region of third molars and the ramus grows mainly in the region of condylar process. Chin prominence also occurs during ontogeny. In the group of adult mandibles the variability is caused by coronoid process height and the body width. The hypothesis, that age groups are significantly different from each other, and therefore due to tooth mineralization there are marked shape changes, is confirmed.
|
guest ::
