Effect of Local Subperiosteal Zoledronic Acid Injection on the Survival of Orthodontic Miniscrews

Anchorage in orthodontics refers to resistance against unwanted tooth movements during treatment. Numerous methods and devices have been utilized over time to reinforce anchorage. Although effective, these traditional techniques present certain limitations.

Recently, mini-implants, or temporary anchorage devices (TADs), have gained popularity as reliable tools for facilitating controlled tooth movement without relying on patient compliance. Nonetheless, miniscrews can encounter complications including mobility and failure during treatment. Clinically, miniscrew success is generally assessed by absence of inflammation, mobility, or significant pain, along with their capacity to withstand orthodontic forces. A systematic review and meta-analysis estimated that TAD failure occurs in approximately 13.5% of cases, with mandibular placements showing a higher failure rate (16.5%) compared to maxillary ones (11.0%).

Bisphosphonates (BPs) are synthetic compounds analogous to pyrophosphates.They are mainly prescribed to manage excessive bone resorption associated with skeletal disorders, primarily by modulating bone remodeling and repair.

The biological effects of bisphosphonates can be categorized into:

• Tissue level: BPs reduce bone turnover, thereby diminishing both bone resorption and formation.
• Cellular level: Osteoclasts are the primary targets, with bisphosphonates inhibiting their recruitment, suppressing activity, shortening lifespan, and modifying bone mineral properties to slow dissolution independently of cellular processes.