Rybak V. Optimization of methods of surgical treatment and rehabilitation of patients with post-traumatic and postoperative jaw defects

The dissertation presents theoretical substantiation and practical solution of the actual problem – increase of the efficiency of surgical treatment and rehabilitation of patients with defects of the maxillofacial area on the basis of three-dimensional restoration of bone structures by autologous bone grafts with the use of plasma rich in growth factors. The research was aimed at studying the features of resorption and remodeling of bone grafts in patients with postoperative and post-traumatic defects of the jaws and factors influencing the course of these processes. Studying the platelet content in PRGF EndoRet, improving the methods of surgical treatment of post-traumatic and postoperative bone defects, combined bone autograft and plasma rich in growth factors (PRGF), clinical indications and techniques for their use depending on the clinical features and the pathogenesis of etio-pathological conditions. The use of modern methods of computer modeling and CAD / CAM technology allowed to improve the quality of diagnosis and planning of therapeutic measures in patients with defects and jaws due to the precise determination of the geometry and extent of the defect (the error of calculations did not exceed 5 %) and also to increase the efficiency of the surgical procedures. During the clinical and radiological study, it was found that post-traumatic and postoperative defects of the facial bone replacement with autologous bone grafts from iliac crest, the latter undergo intense resorption and remodeling, accompanied by a decrease in the volume of the graft by 65.1 ± 21.8 % and an increase in its radiological density. The most intense resorption of the graft is observed in the first 6 months after the operation (45.6 ± 21.8 %) and proceeds mainly in the spongious bone. In the next process, the loss of volume is slowed down and during the next 6-8 months is 35.8 ± 12.3 %. There are statistically significant correlation between the initial graft volume and the degree of its resorption in the 6 months after surgery (r = 0.64, p < 0.05), in addition, the increase in mineral density during transplant remodeling was more pronounced in the transplants smaller size r=0.76 (p<0.05). The application of xenogeneous bone replacement materials in the study series showed the highest volumetric stability in the longterm postoperative period (on average 19.9 ± 8.1 % versus 45.6 ± 21.9 % when using autograft). The use of plasma rich in platelets in combination with autologous bone grafts to replace defects in the jaws makes it possible to accelerate the regeneration of soft tissue and reduce the time of wound epithelization, postoperative edema and pain syndrome, and reduce the frequency of purulent-inflammatory complications (9.2 % vs. 15.1 %) but probably did not affect the severity of postoperative resorption and remodeling of bone grafts.