En-masse intrusion and retraction with preadjusted edgewise appliance using two different sites of mini-implant placement

Abstract

This article compares the treatment outcome between two patients when en-masse intrusion and retraction of the maxillary anterior teeth were performed with mini-implants placed at different sites. Both the patients had a skeletal Class II malocclusion with Angle's Class I molar relation, Class I canine relation, proclination of upper and lower anterior teeth. In the first case, intrusion and retraction was done with conventional friction mechanics for space closure and an intrusive force from a mini-implant placed in the midline. In the second case, intrusion and retraction were done with the application of force from the anterior attachments to mini-implants placed between the second premolars and first permanent molar bilaterally. There was intrusion of the maxillary anterior teeth with both mechanics. However, the evaluation of treatment outcome at the end of space closure showed mesial movement of the maxillary first permanent molar in the first case. In the second case, distal movement and intrusion of the maxillary first permanent molar and decrease in the lower anterior facial height was noted. The mechanics in the first case can be applied for intrusion and retraction of maxillary anterior teeth when anchorage requirement is not critical. The mechanics described in the second case can be used for intrusion and retraction of maxillary anterior teeth in cases with a very high anchorage need and will be beneficial in patients with vertical growth pattern.