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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.
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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.
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Analysis of forces acting on the mandible during chewing
Thomková, Barbora ; Hájek, Petr (referee) ; Marcián, Petr (advisor)
The bachelor thesis deals with cranio-maxillo-facial biomechanics by analysing the force of the lower jaw during chewing. In the thesis, research study of literary sources dealing with the force of the lower jaw is carried out, from which the information obtained was used for subsequent analysis of the force effect on the lower jaw during chewing. The solution is made referring to computational modelling, analytical methods and also numerical by using FEM. The analytical solution was made on the assumption that the lower jaw is a rigid body and solved the magnitude of the contact forces in the bonds and the bite force that was considered at different positions using equations of equilibrium. The numerical solution was computed by using the ANSYS Workbench software. Two types of kinematic bonds (spherical and fixed support) in the condyle areas were solved and compared. The first type was identical with the analytical solution. Spherical bonds were prescribed at the place of the condyles. The second type of bonds was chosen on the basis of literature. Fixed support bonds were selected in both condyles. The results were compared for both approaches related to solution and the biting forces were compared with the experimentally determined values reported by the literature.
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Prediction of mechanical properties of the cancellous bone tissue of the mandible
Holá, Lucia ; Valášek, Jiří (referee) ; Thomková, Barbora (advisor)
The bachelor thesis deals with a problem from the field of biomechanics, specifically to determine mechanical properties of cancellous bone tissue of lower jaw and is focused on Young´s modulus of elasticity and apparent bone density detection. In this thesis a research of studies that were focused on determining a relationship between E and apparent density of trabecular bone is firstly included. Then solution is made using computational modeling using finite element method on the model of lower jaw that was constructed from CT scans. In the SolidWorks software, 12 cubes were made and inserted into the model that was later used in software called ANSYS Workbench, to calculate force reactions and E value using CT number values also calculated in the software. Calculated values of force reactions were then used for Young´s modulus calculation for each axis x,y and z using equations obtained from literature. Next solution was made using the ImageJ program in which values of Hounsfield units were obtained and later recalculated into apparent density values using mathematical relations. Then values of E as a function of CT number and E values obtained from mathematical relation were compared. Lastly the relationships between E and density were determined.
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A research study of plate for the treatment of tumorous mandible
Mäsiar, Matúš ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This bachelor’s thesis aims to address the issue of treating tumorous conditions in the lower jaw by implementing a reconstructive plate. The thesis includes an examination of basic anatomy related to the specific problem, along with a research study on the utilization of reconstructive plates based on available literature. Subsequently, a stress-strain analysis of the lower jaw with the two different applied reconstructive plates was performed using computational modeling, specifically employing the finite element method within ANSYS Workbench 22.2. The thesis provides a detailed description of the creation of two variations of the computational model, followed by an evaluation of the stress and deformation exhibited by the system.
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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.
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Prediction of mechanical properties of the cancellous bone tissue of the mandible
Holá, Lucia ; Valášek, Jiří (referee) ; Thomková, Barbora (advisor)
The bachelor thesis deals with a problem from the field of biomechanics, specifically to determine mechanical properties of cancellous bone tissue of lower jaw and is focused on Young´s modulus of elasticity and apparent bone density detection. In this thesis a research of studies that were focused on determining a relationship between E and apparent density of trabecular bone is firstly included. Then solution is made using computational modeling using finite element method on the model of lower jaw that was constructed from CT scans. In the SolidWorks software, 12 cubes were made and inserted into the model that was later used in software called ANSYS Workbench, to calculate force reactions and E value using CT number values also calculated in the software. Calculated values of force reactions were then used for Young´s modulus calculation for each axis x,y and z using equations obtained from literature. Next solution was made using the ImageJ program in which values of Hounsfield units were obtained and later recalculated into apparent density values using mathematical relations. Then values of E as a function of CT number and E values obtained from mathematical relation were compared. Lastly the relationships between E and density were determined.
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|
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Analysis of forces acting on the mandible during chewing
Thomková, Barbora ; Hájek, Petr (referee) ; Marcián, Petr (advisor)
The bachelor thesis deals with cranio-maxillo-facial biomechanics by analysing the force of the lower jaw during chewing. In the thesis, research study of literary sources dealing with the force of the lower jaw is carried out, from which the information obtained was used for subsequent analysis of the force effect on the lower jaw during chewing. The solution is made referring to computational modelling, analytical methods and also numerical by using FEM. The analytical solution was made on the assumption that the lower jaw is a rigid body and solved the magnitude of the contact forces in the bonds and the bite force that was considered at different positions using equations of equilibrium. The numerical solution was computed by using the ANSYS Workbench software. Two types of kinematic bonds (spherical and fixed support) in the condyle areas were solved and compared. The first type was identical with the analytical solution. Spherical bonds were prescribed at the place of the condyles. The second type of bonds was chosen on the basis of literature. Fixed support bonds were selected in both condyles. The results were compared for both approaches related to solution and the biting forces were compared with the experimentally determined values reported by the literature.
|
|
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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.
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|
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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.
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