SUMMARY
Summary. Histomorphometry of bone tissue is still an important method for an objective evaluation of mechanisms of remodeling at the level of cells and tissues, which allows us to reliably study morphological manifestations in jaw bones in various diseases. For evaluation of morphological changes in jaw bones in these pathological conditions modern computer technologies are often used. However, in the analysis of professional literature, we have not found data about the features of microarchitecture of jaw bones located in areas affected by radicular cysts.The aim of the study – to conduct a histomorphometric study of jawbone areas affected by radicular cysts by using modern computer technologies.Materials and Methods. 44 patients (29 males and 15 females) aged 20 to 70 years with radicular jaw cysts who were on an outpatient treatment were examined. In 23 patients, tumor-like neoplasms were located on the upper jaw, and in 21 – on the lower jaw. Histological materials for histomorphometric study were obtained during radicular bone removal (cystectomy). For the morphometric analysis, ImageJ v.1.48u software was used. Each shot was investigated three times, the average area value for each shot was calculated. After semi-automatic image transfer of histoparticles into black and white (binary masks), using the ImageJ software, the following parameters were measured: trabecular space, intertrabucular space, the area of ??the cross-section between the trabecular space (µm2) and the histomorphometric coefficient of bone density. Statistical processing of the obtained research results was carried out with the help of the computer program of statistical calculations «Statistica 8».Results and Discussion. In histomorphometric studies of bone biopsies taken from intact jaw sections it was found that the density of bone tissue in the mandible statistically significantly differs from the upper jaws. In the patients during histomorphometry of bone biopsy samples taken from the jaw sections adjacent to the shells of small and medium sized radicular cysts, we found in them a significantly greater trabecular density in the spongy structure compared with intact bones. When comparing the morphometric indices obtained during the study of the maxillary bones affected by large cysts with those in the maxillary bones adjacent to the cysts of medium to small size, a tendency towards further consolidation of bone tissue in response to increasing compression on the side of these tumor-like neoplasms was found. The process of bone tissue sealing was more intense on the lower jaw. Compared to intact bones, there was a statistically significant increase in the number of bone trabeculae in jaw regions undergoing chronic pathological effects from radicular cysts. When comparing the architecture of the spongy bone in the biopsy of the mandibular bones taken from the areas adjacent to the cysts of big sizes, with the data obtained in the study of bone tissues adjacent to smaller cysts, a statistically significant difference was established between them.Conclusions. In response to the pathological effects of radicular cysts, irrespective of their size, an adaptive-compensatory reconstruction of the jaw bones occurs that morphologically manifests as a sealing of their trabecular structure, and the decrease of the intertrabecular space.