SUMMARY
There is a signifi cant scientifi c and practical interest in the study of bone mineral density in the jaw destructive processes caused by tumors in patients without bone remodeling disorders on the background of osteoporosis.The aim of the study – to conduct a comparative evaluation of jaw bone optical density in areas adjacent to radicular cysts depending on the osteoregenerating status of patients.Materials and Methods. 45 patients (20 males and 25 females) aged 20 to 70 years with radicular jaw cysts who were on an outpatient treatment at the Surgical Department of the Medical Stomatological Center of Danylo Halytskyi Lviv National Medical University were examined. Determination of bone mineral density (BMD) in patients was conducted by ultrasound bone densitometer Achilles (LUNAR Corp. (USA)) by measuring the time of ultrasonic waves pass through the calcaneus. Bone mineral density in patients was analyzed for the Z criterion. All patients underwent standard orthopantomograms on an X-ray apparatus Orthophos XG (Sirona). For the qualitative characteristics of mandibular cortical layer we used MCI index (mandibular cortical index) by Klemetti E. et al. (1994). According to published data, the index serves as an indicator of MCI systematic reduction of mineral density of the facial skeleton. Digital orthopantomograms analyzed by using the ImageJ software, which allows measuring the optical density of bone tissue at any selected jawbone area in standard brightness units in grayscale from 0 to 256 (the minimum values correspond to the background of the radiographs). The optical density of bone tissue was determined in a region directly adjacent to the shell of the radicular cyst, and compared with the intact bone on the symmetrical side of the jaw. Statistical analysis of the research results was carried out by a computer program of statistical calculation Statistica 8.Results and Discussion. As a result of ultrasound densitometry of the calcaneus in 17 women aged 45 to 60 years, we found signs of osteopenia and osteoporosis. Indicators of BMD within the age norm were detectedin 6 surveyed women who were younger than 45 years. Among the surveyed men of all ages signs of age norms were found much more frequently – in 11 cases. The MCI mandible index is in 87 % of cases directly correlated with state of bone mineral density determined by ultrasound densitometry, which is being consisted with literature data. In the absence of systemic disorders of mineral metabolism, the parameters of optical density in areas adjacent to the shells of the radicular cysts were higher compared to intact bones (p <0.05), which, in our opinion, testifi es about the compensatory reaction of the bone tissue that is subjected to pathological infl uence (compression) from the side of the cyst shell. On the background of systemic osteoporosis, optic density of jaw bones in the area of injury compared to intact sides is decreased.Conclusions. Determination of the optical density of the jaw bones adjacent to the radicular cysts can be used as a screening test for the study of osteo-regenerative potential in patients and should be taken into account when choosing surgical treatment methods.