Long-term stability of Angle class Ⅱ malocclusion after orthodontic treatment
[Abstract] Objective To evaluate the trend of change in Angle's Ⅱmalocclusion after orthodontic treatment,and to analyze some possible factors which may predict or affect these changes,providing some reference for the clinical practice.Methods The sample consisted of 60 patients with Angle class Ⅱmalocclusion between 10~26 years,the patients before 16 years were divided into Group A,those after 16 years were divided into Group B.To evaluate the study models of pre-treatment,post-treatment and out of retention,ten variables were chosen to evaluate the change of occlusion paired T test,analysis of variance,correlation analysis were applied to the data. Results The dental relationship tend to return toward their pretreatment values after treatment,while still remaining a major part of the correction.The values have significant differences between the group A and B. Conclusion The early treatment is stable;the maxillary intercuspid width tended to be more stable than the mandibular one. The mandibular intercuspid width decreased significantly accompanied by the relapse of mandibular crowding.