Abstract: Objective To investigate the clinical effect on the distalization of maxillary molars with mesial oblique movement during mixed dentition stage using the casting stent combined with the segmental arch technique.Methods 12 patients with mesial momvement of first permanent molars were selected, casting stent combined with the edgewise segmental arch technique was used to distalizate maxillary first molars .The cone bundle CT before and after treatment was measured and analyzed, and the opposite side teeth were used as the control to compare the position changes of maxillary first permanent molars before and after treatment.Results In all cases, the crown of the first permanent molar on the affected side moved distally, with an average distally moving amount of 4.82 ± 1.45mm, the mesial inclination of the tooth axis decreased by 7.05 ± 3.25°（P<0.05）, and the mesial torsion of the crown was improved, with an average of 9.09 ± 1.61°（P<0.05）. Conclusion Casting stent combined with segmental arch technique can effectively treat the mesial oblique movement of maxillary first permanent molars in the mixed dentition stage and adjust the maxillary first molars to the normal position.

Key words: Molar distal movement, Casting stent, Segmental arch technique, Cone-beam CT