Evaluation of the effects for root resorption in orthodontic tooth movement with micro-osteoperforations in mice.

Background/purpose: Orthodontic treatment is one of the most demanding procedures available for both patients and clinicians. The challenges stem from the extended duration to achieve desired results, often necessitating surgical interventions, such as micro-osteoperforations (MOPs). This study aimed to investigate the biological effects and extent of changes resulting from these interventions. Specifically, we evaluated the degree of root resorption during orthodontic tooth movement accelerated by MOPs. Materials and methods: We assessed the tooth movement rates and root resorption in eight-to ten-week-old male mice. A nickel-titanium (Ni-Ti) closed-coil spring was applied between the maxillary left first molar and maxillary incisors. In the MOPs group, micro-perforations were made on the mesial and palatal surfaces of the left maxillary first molar. Odontoclast formation and root resorption were assessed using histological analysis and scanning electron microscopy. Results: Tooth movement was greater in the MOPs group. Odontoclast formation was remarkably higher in this group than in the orthodontic tooth movement (OTM) group. Additionally, more extensive root resorption was observed on the mesial surface of the distobuccal root of the left maxillary first molar. Conclusion: Root resorption significantly increased in mice with MOPs. These findings highlight the need to carefully consider the risk of root resorption in patients undergoing MOPs during orthodontic treatment.