COMPARATIVE ANALYSIS OF POST-TRAUMATIC DYNAMICS OF MANDIBULAR BONE QUALITY DEPENDING ON THE TYPE AND LOCATION OF BONE INJURY

Bone injuries of the maxillofacial region include traumatic fractures of the jaws of various etiologies and post-extraction bone-destructive injuries. One of the key criteria in selecting the optimal treatment strategy for bone defects and preventing their complications is the assessment of jaw bone tissue quality, the post-traumatic dynamics of which depend on the type of injury and the method used to restore bone integrity.Objective. To determine the normative density values of bone tissue in various regions of the mandible in intact rats and to identify the patterns of their post-traumatic changes.Materials and Methods. The study was conducted on 35 sexually mature outbred male rats aged 3–3.5 months and weighing 180–210 grams. The animals were divided into three experimental groups of 10 rats each, and an additional 5 rats comprised the control group. Bone injury was modeled by disrupting the integrity of mandibular bone tissue using a dental bur in the area of the mandibular angle (Group 1) and in the interdental space (Group 2), as well as by extraction of the second molar (Group 3).Bone tissue quality was assessed in the injured, adjacent, and contralateral regions of the mandible using a Siemens dental radiovisiograph with TrophyRadiology software, at 1, 2, and 3 weeks post-injury. Bone density was measured in conditional grayscale units (CGU).Results and Discussion. It was established that the lowest bone density values in the mandibular body were found in the area of the mandibular angle, while the highest were observed in the region of the molars. All baseline density indicators were symmetrical. The post-traumatic dynamics of bone quality varied depending on the location and type of injury.In the trauma zones, regardless of their anatomical location or origin, a similar pattern was observed: bone density significantly increased during the first two weeks of the experiment and decreased by the end of the third week.After injury to the mandibular angle, no significant changes in bone density were noted in other examined regions of the mandible. In contrast, trauma in the interdental space resulted in a decrease in bone density in the contralateral (left) interdental space and in the incisor regions bilaterally, alongside an increase in bone density in the molar regions on both sides. Following extraction of the second molar, bone density in the symmetrical region on the contralateral side gradually increased, whereas on the side of the extraction, the density decreased in the interdental and incisor areas.Bone density in the mandibular angle remained unchanged when bone-destructive injuries were inflicted in other regions, and for the entire duration of the three-week experiment, these values did not differ from those observed in the control (intact) animals.Conclusion. During the post-traumatic period, changes in bone quality were driven by a combination of factors, including regenerative processes and masticatory load. This explains the variable dynamics of bone density across different regions of the mandibular body, depending on the origin and localization of bone-destructive injuries.