Abstract: Objective： To investigate the effect of local periodontitis on orthodontic tooth movement in a mouse model. Methods: 12-week-old C57 mice were enrolled, and injected with lipopolysaccharide (LPS) via the gingiva lateral to the maxillary molar region to establish a model of periodontitis. Mice injected with the same volume of saline were included into the control group. Alveolar bone loss was scanned and quantitatively analyzed using Micro-CT. A mouse model of orthodontic tooth movement was established during the stationary phase of periodontitis. The density of maxillary bone and the distance of tooth movement were scanned and quantitatively analyzed using Micro-CT with the force value set at 30 g at a duration of 7 days. Results：The orthodontic tooth movement during the stationary phase of LPS-induced periodontitis demonstrated a slight decrease in the bone mineral density of maxillary bone (P < 0.05), and a remarkable increase in the distance of tooth movement (P < 0.05) when compared to that after saline injection. Conclusions: Local periodontitiscan facilitate orthodontic tooth movement in mice. Our findings will provide references for the effect and risk assessment of tooth movement in the combined therapy of periodontics and orthodontics in clinical practice, and provide guidance for the optimization of orthodontic tooth movement.