ORTHODONTIC TREATMENT IN PATIENTS UNDER ANTIRESORPTIVE THERAPY: BIOLOGICAL BASES AND IMPLICATIONS FOR OSTEONECROSIS OF THE JAWS

Abstract

Objective: To review the experimental, in vitro, and clinical literature to characterize the biological mechanisms by which antiresorptive agents (bisphosphonates and denosumab) affect bone remodeling and orthodontic tooth movement, as well as to examine reports of Medication-Related Osteonecrosis of the Jaws (MRONJ) associated with orthodontic therapy.

Materials and Methods: Narrative review of published evidence, including preclinical studies, controlled clinical trials, and case reports, with emphasis on cellular alterations (osteoclastic activity, senescence, reactive oxygen species—ROS), mechanosensitive inflammatory responses, and radiographic/histopathological findings.

Results: Antiresorptive agents inhibit osteoclastic activity, increase bone mineral density, and reduce the rate of orthodontic tooth movement; zoledronic acid promotes a hyper-inflammatory response of the periodontal ligament under compression and causes cellular DNA damage, while denosumab shows a localized anchorage effect when applied locally. Clinical cases indicate the temporal manifestation of MRONJ after the onset of orthodontic tooth movement, with symptoms ranging from tooth mobility to extensive bone exposure. Clinical management involves individualized risk assessment, conservative and surgical strategies, and measures to reduce local trauma.

Conclusion: There is consistent evidence that antiresorptive agents negatively alter the bone remodeling required for orthodontics and may increase the risk of MRONJ; light orthodontic mechanics, prevention of aggravating factors, and an interdisciplinary approach are recommended. Prospective clinical studies and biomarkers (e.g., GDF15) are needed to guide safe protocols.