MORPHOLOGICAL AND RADIOLOGICAL ASPECTS OF MANDIBULAR BONE REMODELLING AFTER ACTIVATED CHITOSAN IMPLANTATION

Introduction. Bone regeneration remains a complex and challenging area for modern medicine. This study aims to provide a comprehensive understanding of the dynamics of bone tissue remodeling after defect creation and filling with chitosan-based osteoplastic material. While osteoplastic materials are widely used clinically, and chitosan offers unique properties, its impact on maxillofacial bone regeneration, particularly the underlying mechanisms and dynamics, is not fully understood and requires further clarification and detailed investigation. Aim: this study aims to determine and compare the morphological, radiological, and lectin-histochemical characteristics of osteoregeneration after the transplantation of activated chitosan (Chitosan-A) into an experimental defect in the rabbit mandible. Materials and methods. The study was carried out on mature male rabbits aged 6-7 months, weighing 2.5-3 kg. The control group included animals with a bone tissue defect that healed under a blood clot. The experimental group consisted of rabbits in which the bone defect was filled with activated chitosan (Chitosan-A). The post-traumatic state of bone tissue in the defect area was monitored over a period of 84 days using the following methods: bone defect modeling, assessment of jaw macrostructure, radiographic examination, radiovisiography, microscopic analysis of bone sections, and lectin-histochemical analysis of decalcified bone sections. Results. Examination of the macrostructure of the experimental bone defect in the rabbit mandible, following the implantation of chitosan activated with acetic acid (Chitosan-A) into the defect cavity, revealed extensive regenerative changes associated with injury recovery. These findings correlated with data obtained from radiographic and radiovisiographic examinations. Microscopic analysis of bone sections demonstrated a staged progression of regenerative changes and provided insights into the composition of the regenerate. Conclusions. The use of Chitosan-A was shown to modulate tissue development and remodeling throughout the experiment. Bone density in the experimental group approached normal levels, being only 10.2% lower than in the control group at the end of the study. Microscopic examination revealed bone tissue remodeling with incomplete geometry of newly formed osteons and residual traces of the Chitosan-A material.