Evaluation of bone changes in the mandible after implant-supported overdenture prosthetic treatment in total edentulous patients with fractal analysis

Objective: The loss of all teeth results in a reduction in muscle tone and mass of the masticatory muscles, leading to decreased bite force and ineffective mastication. Although patients with total edentulism are treated with conventional complete dentures, these dentures often lack adequate retention and stability, thus failing to provide effective chewing function. As masticatory force decreases, the functional forces exerted on the mandible also diminish. Patients rehabilitated with implant-supported removable prostheses experience improvements in bite force and chewing function due to increased stability and retention. The bony structures are in harmony with functional forces and the mechanical environment. Therefore, microstructural changes in the mandibular bone are likely in totally edentulous patients. The aim of our study is to evaluate the mandibular bone changes in fully edentulous patients using conventional complete dentures, before and after prosthetic treatment with two implant-supported overdentures placed in the mandible. Materials and Methods: Our study included 27 patients who had previously used conventional complete dentures and were treated with two-implant-supported overdentures. Panoramic radiographs taken during the use of conventional complete dentures served as the control group (n=27), while radiographs obtained 4 years (±1 month) after two-implant-supported overdenture treatment formed the study group (n=27). Retrospective panoramic radiographs collected during pre- and post-treatment evaluations or routine examinations were analyzed. For each patient, three symmetric regions of interest (ROIs) were selected on both the right and left sides: the mandibular condyle (ROI-1), the angle of the mandible (ROI-2), and the area anterior to the mental foramen (ROI-3), with each ROI measuring 45x45 pixels. Trabecular bone complexity was assessed using the fractal analysis method. The collected data were statistically analyzed. Results: According to the findings, a statistically significant difference was observed in the fractal dimension measurements of the selected ROI-1, ROI-2, and ROI-3 between the control and study groups (p=0.001) in patients using two-implant-supported overdentures. However, no statistically significant difference was found between the right and left regions in the fractal dimension measurements of ROI-1, ROI-2, and ROI-3 (p=0.814), (p=0.654), and (p=0.296), respectively. Conclusions: Our results indicate that the use of implant-supported overdentures leads to more complex trabecular bone structures in various regions of the mandible compared to the use of conventional complete dentures.