Studies of at least 10 implants in patients of any age who required absolute anchorage for orthodontic purposes and reported success rates of mini-implants less than 2.5mm in diameter were eligible for inclusion. Studies had to provide a definition of success after 120 days of force application that was reported at a predetermined time or at completion of orthodontic anchorage objectives. Studies on miniplates were excluded, as were articles that dealt with technique or opinions, case reports, reviews and in-vitro studies.
Primary outcomes (immobility, mobility, displacement and failure) were success or failure of mini-implants as anchorage devices during orthodontic tooth movement. Secondary outcomes incorporated complications that arose from treatment (biologic damage, inflammation and pain and discomfort measures).
In included studies, force levels varied from 50g to 400g; most studies used 200g or less. Duration of force application varied from three to 37 months. Timing of assessment of study outcomes varied from three to 27 months after application of orthodontic forces. Implant types varied between and within included studies. Implant diameters ranged from 1.0mm to 2.3mm. Mean age of participants ranged from 12.2 to 34.3 years. Most participants were female.
Two reviewers independently selected studies for inclusion in the review. Disagreements were resolved by consensus.