Three-Dimensional Evaluation on the Effect of Maxillary Dentition Distalization With Miniscrews Implanted in the Infrazygomatic Crest.

Objective: To evaluate the effect of the maxillary dentition distalization with miniscrews implanted in the infrazygomatic (IZ) crest with 3D reconstruction module from cone-beam computed tomography (CBCT). Methods: Twenty patients who previously underwent dentition distalization treatment with miniscrews were recruited. A total of 40 images were obtained using CBCT, taken immediately before placement of the miniscrew anchorage and at the end of distalization. The 3D-line measurements were recorded to monitor dental changes. Results: There was significant movement of maxillary dentition before and after treatment with miniscrews. The miniscrews induced maxillary dentition distalization and corrected Class II relationship in 8 months on average. The incisors were retracted 4.3 mm and extruded 3.8 mm at the crown on average. The crown of canines showed 3.7 mm of distalization and the width increased by 3.1 mm averagely. The mesial buccal cusp of first molars' crowns showed 3.5-mm distalization and 2.1-mm intrusion, and the width increased by 5.0 mm averagely. The distal buccal cusp of first molars' crowns showed 2.8-mm distalization and 3.7-mm intrusion, and the width increased by 6.2 mm averagely. Conclusions: The anchorage of miniscrews implanted in the IZ crest is an efficient device for maxillary dentition distalization.