ABSTRACT
21 classII malocclusion adolescents (9 boys and 12 girls) were selected as the subjects, aged from 10.6 to 14.5 years, and the initial mean age was 12.8 years. All were treated with the modified Pendulum appli-ance. The duration for distalization of maxillary molars was from 3.2 to 5.7 months (4.3 months on average). Lat-eral cephalograms were obtained before and after distalization. Changes produced by the modified Pendulum appli-ance were analyzed with paired t tests. The mean space opening on lateral cephalograms was 7.31 mm, and maxil-lary first molar distalization accounted for 64.8% of the space,with a mean distal crown tipping of 18.64o. The rate of molar movement was 1.27 mm per month. The maxillary first molars intruded 0.69 mm,and the premolars extru-ded 1.02 mm. Lower anterior facial height increased 2.19 mm. The maxillary incisors had increased 3.39oof labial tipping and 1.13 mm of protrusion.