Aim: To determine the efficacy of mini-implants as intraoral anchorage during en masse intrusion of the six maxillary anterior teeth. Methods: Ten patients from the Department of Orthodontics, KLE University, Belgaum, India, who required intrusion of their anterior teeth were selected for this study. After initial alignment and leveling, the maxillary arch was divided into one anterior segment and two posterior segments. A 0.021 3 0.025-inch stainless steel wire was placed in all three segments. In all patients, one mini-implant was placed bilaterally between the lateral incisor and canine. An elastic chain was used to deliver an intrusive force of 45 cN; it was supplemented by a distal force of about 20 cN per side. Patient records were taken at the beginning and end of intrusion. Results: The amount of intrusion was statistically and clinically significant. The canines were more intruded (3.5 ± 0.9 mm) than the incisors (2.9 ± 1.0 mm). The axial inclination of the incisors did not significantly change. The average duration to accomplish this intrusion was 4.0 ± 1.5 months, with a mean rate of 0.9 mm per month for the canines and 0.7 mm per month for the incisors. Conclusion: Mini-implants are an efficient and stable source of anchorage for the en masse intrusion of the six maxillary anterior teeth. World J Orthod 2010;11:346–351.
Key words: anchorage, mini-implants, en masse intrusion, deep bite, anterior teeth