MORPHOLOGICAL ASPECTS OF POST-TRAUMATIC LOWER JAW REMODELING IN THE SETTING OF OSTEOPLASTY

Bone tissue regeneration remains a complex and crucial challenge for modern medicine. The unique properties of chitosan, its effects on bone regeneration in the maxillofacial region, as well as the underlying mechanisms and dynamics, remain poorly understood and warrant further investigation. Aim. The aim of the study is to determine the dynamics of morphological, radiological, and lectin-histochemical characteristics of bone-ceramic regenerate after the transplantation of octacalcium phosphate with the addition of chitosan acetate with ampicillin into an experimental defect in the rabbit mandible. Materials and methods. Adult male rabbits aged 6-7 months and weighing 2.5-3 kg were used for the study. The control group consisted of animals with a bone defect that healed under a blood clot. The experimental group consisted of rabbits in which the bone defect was filled with an osteotropic material containing octacalcium phosphate, chitosan acetate, and ampicillin (OCР-N-Chitosan-Ampicillin). Post-traumatic bone tissue status within the defect area was monitored for 84 days. The following methods were employed: bone defect modeling, assessment of jaw macrostructure, radiographic examination, radiovisiography, examination of bone sections under a microscope, and lectin-histochemical analysis of decalcified bone sections. Results. Examination of the macrostructure of the experimental bone defect in the rabbit mandible after implantation of material with octacalcium phosphate, chitosan acetate, and ampicillin (OCР-N -Chitosan-Ampicillin) revealed numerous regenerative changes that occurred after the injury and correlated with the data of radiographic and radiovisiographic examinations. Microscopic examination of bone sections allowed us to establish the phased nature of the dynamics of the studied regenerative changes and the composition of the regenerate. Conclusions. It was established that in the experimental group of animals in which defect repair was performed using OCP-N-Chitosan-Ampicillin material, a shortening of the reactive phase of the post-traumatic inflammatory process was observed, which ensured the active onset of osteoregeneration. The use of this combination of drugs showed accelerated reparative regeneration of the mandible and adjacent mucosa.