ABSTRACT
Objective To investigate nasomaxlllary complex facial soft tissue changes after the treatment with maxillary protraction appliance with skeletal Class Ⅲ malocclusion with a retruded maxilla.Methods Thirty growing subjects with skeletal Class Ⅲ malocclusions with maxillary retrognathism were selected and treated by facial mask(male 15,female 15,with an average age of 10.5).They were given a maxillary protraction treatment with face mask for 6-8 months.Cephalometric measurements about nasomaxillary complex soft tissue changes were analyzed to draw the statistic conclusion.Results After maxillary protraction treatment,PraY,nasofrontal angle,As-Y,UL-Y,UL-E,S-Ns-Sn increased (P ＜ 0.01) ; M-Y increased (P ＜ 0.05) ; LL-E,PosY,nasolabial angle decreased (P ＜ 0.05).There were no significant differences in the Ns-Y and columella-tip angle.Conclusion After maxillary protraction treatment,nasomaxillary complex area becomes more marked.Both the nasomaxillary complex soft tissue and lower facial profile are dramatically improved.The combining effect of these two changes results in a more harmony profile.