|
|
Preclinical research of degradation of metallic osteosynthetic alloys in vivo on animal biomodels
Machoň Levorová, Jitka ; Foltán, René (advisor) ; Hauer, Lukáš (referee) ; Hirjak, Dušan (referee)
The dissertation is dealing with the option of using biodegradable metal alloys such as osteosynthetic material in maxillofacial surgery, The hypothesis presupposes that Zn-1,6Mg and WE43 alloys are from the viewpoint of the degradation period and biological interactions suitable for fixation of facial skeleton. The theoretical part of the work evaluates current trends in the use of biodegradable metal alloys. It monitors the development of material for osteosynthesis in maxillofacial surgery emphasizing the biological reactions of material and undesirable qualities including their clinical impact. The experiment part of the work is divided in two successive stages. The first stage used the rat biomodel to implant Zn-1,6Mg and WE43 alloys. The aim was to compare the duration of degradation and to receive the reaction of the ambient tissue. The animals were euthanized in regular intervals. They were scanned ex vivo by means of cone-beam tomography to find the degradation period of each alloy. Histopathological examination was performed to receive the reaction of the ambient bone tissue. The conclusion evaluates WE43 alloy is more suitable for osteosynthesis in the facial skeleton according to the results of the first stage. The second stage used the rabbit biomodel for implantation of WE43 and titanium as a...
|
|
|
New bone production and regeneration using stem cells
Klíma, Karel ; Foltán, René (advisor) ; Bulik, Oliver (referee) ; Németh, Tibor (referee)
Introduction: A lack of bone mass poses limits on treatment in maxillofacial surgery, orthopaedics and traumatology. This post-gradual research aimed to confirm the hypothesis that inorganic or organic non-cellular bone matrix could act as a carrier for autologous stem cells able to differentiate into osteoblasts as well as to verify whether we could accelerate regeneration of the augmentation and the healing process, resulting in improving the bone quality. Materials and methods: Regenerative properties of the bone were explored using bone marrow stem cells with hydroxyapatite and tricalcium phosphate in a rat bone defect and spinal fusion model. A simple spinal fusion model was induced in a rat capable of easy reproduction, with the least possible mortality and morbidity. After the 8-week experiment, the rodents were euthanized. All samples were analyzed using micro-CT and histomorphometry. Results: The research on a rat bone defect showed that stem cells with hydroxyapatite and tricalcium phosphate led to a significantly higher bone regeneration. It was proved that a higher concentration of stem cells caused a bigger body mass increase. The research on a spinal fusion model demonstrated that stem cells reduced inflammation and improved bone quality but did not significantly accelerate bone...
|
|
|
Preclinical use and critical evaluation of micro-CT from the perspective of oral and maxillofacial surgery.
Bartoš, Martin ; Foltán, René (advisor) ; Naňka, Ondřej (referee) ; Bulik, Oliver (referee)
The preclinical imaging method micro-CT (microtomography) allows the visualization and quantification of the structure of samples at a resolution of micrometers. Its' importance is increasing globally. In addition to several advantages (non-destructive, the possibility of direct 3D analysis, time efficiency, etc.), micro-CT also has some significant limitations (problematic validation of results, image artifacts, significant influence of image modifications, etc.). This thesis focuses on the application of micro-CT in the field of research and development of metallic and non-metallic materials promoting bone healing with their possible clinical applications. The first part addresses the limitations of micro-CT through several studies. A comparison of pore sizes in biomaterials utilizing scanning electron microscopy (SEM) and micro-CT was performed, and the complications of pore size evaluation were presented. SEM image analysis leads to significantly higher values than micro-CT (approximately three times), which allows for comparison of the studies using only one of these methods. Validation of micro-CT 3D analysis results based on calibration phantoms with complex structure, to date, is not possible. We therefore developed software generating phantom datasets of 3D objects with well-defined...
|
|
|
Periopathogens and systemic markers in etiology and diagnostics of periodontal and cardiovascular diseases.
Myšák, Jaroslav ; Foltán, René (advisor) ; Izakovičová Hollá, Lydie (referee) ; Markovská, Neda (referee)
Periodontitis is a disease primarily affecting tooth attachment, i.e. concerning oral cavity, however, its connection to a number of systemic diseases is apparent nowadays. Oral microorganisms and their interaction with the immune system of their host play a significant part in the etiology of this multifactorial disease. Rapid development of DNA-based diagnostic methods in the last 15 years dramatically increased the spectrum of identified oral microorganisms and promoted understanding of how particular taxons correlate with periodontal health or disease. Moreover, next generation sequencing methods also bring new possibilities to study the relationship between periodontitis and other diseases such as diabetes mellitus, cardiovascular diseases (CVD), stroke, lung infection or kidney diseases, etc. The presented work focuses on the use of sequencing methods to compare the taxonomic composition of microbiomes within oral cavity and the tissues of aortic valves in patients suffering from CVD. The characterisation of taxonomic composition of microbiome in the analysed tissues was performed using the method of 454 pyrosequencing of variable region IV-V of the bacterial 16S rDNA. The present taxons were determined by comparing the obtained sequences with the Human Oral Microbiome Database. The common...
|
|
|
New bone production and regeneration using stem cells
Klíma, Karel ; Foltán, René (advisor) ; Bulík, Oliver (referee) ; Németh, Tibor (referee)
Introduction: A lack of bone mass poses limits on treatment in maxillofacial surgery, orthopaedics and traumatology. This post-gradual research aimed to confirm the hypothesis that inorganic or organic non-cellular bone matrix could act as a carrier for autologous stem cells able to differentiate into osteoblasts as well as to verify whether we could accelerate regeneration of the augmentation and the healing process, resulting in improving the bone quality. Materials and methods: Regenerative properties of the bone were explored using bone marrow stem cells with hydroxyapatite and tricalcium phosphate in a rat bone defect and spinal fusion model. A simple spinal fusion model was induced in a rat capable of easy reproduction, with the least possible mortality and morbidity. After the 8-week experiment, the rodents were euthanized. All samples were analyzed using micro-CT and histomorphometry. Results: The research on a rat bone defect showed that stem cells with hydroxyapatite and tricalcium phosphate led to a significantly higher bone regeneration. It was proved that a higher concentration of stem cells caused a bigger body mass increase. The research on a spinal fusion model demonstrated that stem cells reduced inflammation and improved bone quality but did not significantly accelerate bone...
|
|
|
není uveden
Foltán, René ; Mazánek, Jiří (advisor) ; Kalvach, Pavel (referee) ; Klozar, Jan (referee)
In the thesis the author deals with the surgical technique of the genioglossus advancement and hyoid myotomy (GAHM) in the obstructive sleep apnoea syndrome (OSAS) therapy. He focuses in particular on methods used to widen the upper airway by surgical modification of facial bones. Following the definition of the research objective in Chapter 1 and the general introduction in Chapter 2, we can find in Chapter 3 the description and definition of OSAS as well as physiological, pathophysiological and epidemiological notes on sleep, ventilation in sleep and OSAS. In Chapter 4 the author recommends some new methods of examining the upper airway that can be applied in an ordinary dental surgery to predict the risk of development or occurrence of OSAS in some patients. Chapter 5 includes an overview of therapeutic options for OSAS and a detailed description of different GAHM techniques. In accordance with the research objectives and the methodology described in Chapter 6, the results in Chapter 7 show, for a large sample of examined patients, the dependence of obesity (as expressed by the BMI) on the severity of OSAS, along with some cephalometric values in which such dependence has not been published so far. Then the chapter documents a high success rate of GAHM treatment of OSAS in operated patients. This is so,...
|
|
| |
guest ::
