Aim: Distal movement of maxillary molars is a reasonable but often challenging treatment alternative for patients with a dental Class II occlusion and an increased overjet or anterior crowding. One problem is that most of the conventional noncompliance devices that distally move maxillary molars lead to some anchorage loss. As such, a new appliance was designed that is connected to two coupled mini-implants with exchangeable abutments. The aim of this study was to evaluate the effectiveness of this system for distal movement and the extent of its adverse effects. Methods: Maxillary molar distal movement was performed in 18 patients (10 females, eight males) in 6 to 10 months. The appliance (Beneslider) combined elements of the distal jet and Keles slider with two abutment mini-implants (spider screws or Benefit mini-implants). Pre- and posttreatment casts were scanned with cone beam computed tomography. To assess the amount of molar distal movement, molar rotation and transverse expansion the 3D scans were digitally superimposed. Lateral cephalograms were used to measure molar tipping. Results: The mean distal movement of the first molars amounted to 4.6 ± 1.5 mm, the mean mesial rotation to 3.4 ± 2.0 degrees, the transverse expansion in the first molar region to 1.9 ± 1.0 mm, and the distal tipping to 1.9 ± 1.3 degrees. Conclusion: Two coupled mini-implants with exchangeable abutments and a heavy wire were an effective way to bodily move maxillary molars distally. World J Orthod 2010;11:331–340.
Key words: molar distalization, TADs, mini-implants, Class II treatment