A stress-driven model for bone density evolution in rats during orthodontic tooth movement.

Orthodontic bone remodeling simulations offer a scientific foundation for optimizing treatment plans and predicting outcomes in orthodontics. Since alveolar bone exhibits unique regional responses and high sensitivity to tensile and compressive stresses, traditional models often fail to account for these characteristics, limiting their accuracy in predicting the microstructural changes of alveolar bone under external forces. To address this issue, this study proposes a bone remodeling model based on equivalent stress derived from the Mohr strength theory as the mechanical stimulus. The model differentiates tension and compression zones within the alveolar bone and simulates density changes driven by the orthodontic remodeling process: bone formation in tension zone and resorption in compression zone. Orthodontic experiments on rats were conducted to monitor changes in alveolar bone density at 7 and 14 days. Results revealed a density increase of around 3.16% and 9.84% in tension zone and a decrease of approximately 4.86% and 3.61% in compression zone on days 7 and 14, respectively. A comparison between the experimental data and the simulation results of the bone remodeling algorithm demonstrated a consistent trend, validating that the proposed model effectively reflects the dynamic process of bone remodeling. This study provides a new perspective for orthodontic bone remodeling simulations and lays a foundation for further exploration of the mechanisms underlying alveolar bone density changes.