Abstract: Objective: To study the effect and mechanism of alveolar bone micro-osteoperforation (MOP) technique on periodontal tissue remodeling during tooth movement. Methods: Sixteen female, eight-week-old SPF Sprague Dawley rats were included in the study. MOP was performed on one side but not on the other control side. Upper 1st molar was protracted by 30 g orthodontic force with incisors being anchorage teeth. After 7 days, animals were sacrificed and the micro-CT scanning was performed to measure the tooth movement distance and bone density as well as bone volume fraction around the maxillary first molar. HE staining and immunohistochemical staining were utilized to analyze the alveolar bone remodeling in the periodontal tissue. Results: Orthodontic tooth movement was accelerated after performing MOP (420.82±175.58) μm mesial movement in the MOP + orthodontic force group and (224.87±85.64) μm in orthodontic force alone group. In addition, a more decreased bone mineral density and bone volume/total volume was observed in the MOP + orthodontic force group. Narrow periodontal membrane was observed on the pressure side while wide periodontal membrane was found on the tension side. Moreover, increased IL-6 level was observed in the periodontal tissues of MOP + orthodontic force group. Conclusion: MOP enhances the expression of proinflammatory cytokine in periodontal tissues and promotes the orthodontic tooth movement.

Key words: Micro-osteoperforation, Orthodontic tooth movement , Cytokine