Mukovoz O. Development of surgical accesses, forming retention points in bones and soft tissues by remоving of malignant tumors of the maxillofacial area, for orthopedic rehabilitation

The thesis is devoted to the problem of the enhancement of effectiveness of treatment and improving the quality of life of patients with locally advanced malignant tumors of the oral mucosa by means of optimization of the surgical interventions, the development of new and improvement of existing techniques of orthopedic rehabilitation. In the experiment with white rats it has been revealed that local irradiation of animals at a dose of 20-40 Gy and 41-60 Gy does not significantly impair the processes of regeneration and reparation, and does not lead to rejection of titanium implants in the early and late periods of implantation. Increasing the doses from 61 Gy and higher is accompanied by the development of inflammation in the bone tissue around the implant, which leads to its rejection at different periods since the launch of the experiment. The results indicate that implantation of titanium implants and local irradiation of rats at a dose of 20-40 Gy and 41-60 Gy does not cause significant changes in lipid peroxidation. During the analysis of the main indicators of homeostasis it has been revealed that after implantation and local exposure of animals to the dose of 60 Gy the protective adaptive response of the body is formed. The obtained results are confirmed by X-ray examination of experimental animals, giving evidence of satisfactory results of implantation of titanium implants against the background of local irradiation at 41-60 Gy. It has been proven that the dose of 45 Gy is an optimal dose of local irradiation which does not cause significant changes in the homeostasis and does not interfere with the processes of implantation of titanium implants. The study was based on the results of surgical and orthopedic treatment of 74 patients with locally advanced malignant tumors of the oral mucosa of stage III-IV without distant metastases. Patients were divided into two groups. The basic group comprised 32 patients who underwent orthopedic rehabilitation through dental implantation or prosthetic repair with removable structures after resection of the mandible. The control group included 42 patients who did not undergo orthopedic rehabilitation. It has been found that the use of the developed system for fixation of bone fragments by pathological fracture in the area of angle of the edentulous mandible significantly improves the quality of life of patients without disturbing the acts of chewing and swallowing, as well as without distorting the overall appearance of the patient's face. It has been proven that orthopedic rehabilitation with dental implants and removable structures in the reconstruction of defects of the mandible is an effective treatment for patients, providing better quality of life through improving the performances of the normal diet. It has been proven that orthopedic rehabilitation with simultaneous reconstruction of defects of the mandible with dental implants, as compared to traditional methods of surgical treatment, does not affect the three-year overall survival of patients with locally advanced malignant tumors of the oral mucosa - 31,25±8,2% and 28,6±6,9%, respectively, but significantly improves the quality of life.