Comparison of rate of canine retraction with conventional molar anchorage and titanium implant anchorage.

INTRODUCTION Various anchorage techniques have been designed for canine retraction. Intraoral techniques have not always been successful, and now implants are widely used for this purpose. A new type of titanium microimplant, with a small diameter and a button-like head, was shown to be an effective source of anchorage for distal movement of the canines. The purposes of this study were to measure and compare the rates of canine retraction with titanium microimplant anchorage and conventional molar anchorage. METHODS The sample comprised 12 patients (8 female, 4 male; mean age, 19.7 years; range, 16-22 years) who were scheduled for extraction of all first premolars. After leveling and aligning, titanium microimplants 1.2 mm in diameter and 9 mm in length were placed between the roots of the second premolar and the first molars. The implants were placed in the maxillary and mandibular arches on the same side in 10 patients and in the maxilla only in 2 patients. A brass wire guide and a periapical radiograph were used to determine the implant position. After 15 days, the implants and the molars were loaded with closed coil springs with a force of 100 g for canine retraction. Preretraction and postretraction lateral cephalograms were taken and superimposed for measuring the amount of retraction. The amount of canine retraction was measured from pterygoid vertical in the maxilla and SN perpendicular in the mandible. RESULTS Mean canine retraction amounts were 4.29 mm in the maxilla and 4.10 mm in the mandible on the implant-anchorage side, and 3.79 mm in the maxilla and 3.75 mm in the mandible on the molar-anchorage side. The rates of canine retraction were 0.93 mm per month in the maxilla and 0.83 mm per month in the mandible on the implant-anchored side, and 0.81 mm per month in the maxilla and 0.76 mm per month in the mandible on the molar-anchored side. CONCLUSIONS Canine retraction proceeds at a faster rate when titanium microimplants are used for anchorage.