Maxillary total arch distalization using midpalatal mini-implant : Case report

Abstract

Orthodontic mini-implant is usually placed in the buccal interdental area for molar distalization or total arch distalization. However, this requires timely replacement of the mini-implant to prevent contact between root and mini-implant and ensuing root resorption. Alternatively, midpalate may be considered as the mini-implant placement site because it has considerably dense bone and there is no interference with roots. Also, distalization forces may be designed to pass through the center of resistance of dentition for translatory distal movement. In this case report, end-on Class II occlusion with lip protrusion was successfully treated by applying distal forces from a transpalatal arch to a lever attached to two midpalatal mini-implants. Anti-rotation bends were bent on transpalatal arch to prevent mesial rotation of first molars during distalization. Another benefit of this approach is that molar distalization may be initiated at the beginning of treatment because distal tipping of molars can be prevented by applying distal force at the level of the center of resistance of molars thus eliminating the need of stiff rectangular archwire. With this approach, time-consuming molar distalization may be initiated at the beginning of treatment and therefore, overall treatment duration can be reduced.