ABSTRACT
<p><b>OBJECTIVE</b>To compare the effects between mini-screw implant and transpalatal arch (TPA) on dentofacial morphology in extraction cases.</p><p><b>METHODS</b>Forty-two cases were divided into two groups. One group (n = 19) had been treated with mini-screw implants and the other group (n = 23) treated with TPA as anchorage control. Sliding technique was used to close extraction space in the two groups. Cephalometric analysis was performed before and after the treatment. The data were analyzed by using independent-samples t test.</p><p><b>RESULTS</b>In the mini-screw implant group, the maxillary incisors were retracted (7.05 +/- 1.89) mm and intruded (1.71 +/- 2.33) mm, The maxillary first molars were distalized (0.45 +/- 3.32) mm and intruded (1.74 +/- 2.66) mm. While in the TPA group, the upper incisors were retracted (4.59 +/- 1.78) mm and extruded (0.93 +/- 1.77) mm. The maxillary first molars were moved (1.65 +/- 1.87) mm mesially and extruded (0.52 +/- 1.59) mm. All the relevant results between the two groups were significantly different (P < 0.05).</p><p><b>CONCLUSIONS</b>As orthodontic anchorage, mini-screw implants were different from TPA. Mini-screw implant could not only retract the upper incisors but also slightly intrude upper incisors and upper molars.</p>