ABSTRACT
Objectives To study the changes of hard tissue before and after orthodontic treatment for Angle's class Ⅲ malocclusion adolescence patient with maxillary front traction. Methods 20 cases of Angle's class Ⅲ malocclusion adolescence patients were treated by front traction in maxilla, while there were 20 cases of Angle's class Ⅰ malocclusion adolescence patients as the control group. Cephalometric a-nalysis was carried out before and after the treatment. Data were analyzed by SPSS11.0 system using paired t-test. Results There were significant increases in the length, anteroposterior diameter and thick-ness of maxillary sinus (P<0.05), while there was no significant differences in the site and central point of maxillary sinus(P>0.05). Conclusions It is a effective approach to change the hard tissue after ortho-dontic treatment for Angle's class Ⅲ malocclusion adolescence patient with front traction in maxillary area.