LONG-TERM STABILITY OF ANGLE CLASS-II, DIVISION-1 MALOCCLUSIONS WITH SUCCESSFUL OCCLUSAL RESULTS AT END OF ACTIVE TREATMENT

The purpose of this study was to examine long-term stability of Angle Class II, Division 1 malocclusions with successful occlusal results at the end of active appliance therapy, search for predictors of relapse , and look for characteristics associated with successful treatment. R ecords taken before and after treatment and a mean of 14.0 years postr etention of adolescent patients treated for a significant Angle Class II, Division 1 malocclusion both with and without tooth extraction wer e evaluated. The sample was limited to successfully treated cases as j udged by subjective evaluation of intercuspation and incisor occlusion of posttreatment study models and included 78 patients. Cephalometric characteristics or postretention occlusion was not considered in samp le selection. The mode response was no change postretention for molar, premolar, and canine relationships and relapse of 0.5 mm for overjet and overbite. Maximum relapse was 3.5 mm for molar, premolar, and cani ne relationship, 3 mm for overjet, and 4.5 mm for overbite. Stepwise b ackward multiple regression analyses revealed no associations between either pretreatment characteristics or skeletal and dental treatment c hanges and relapse of overjet. However, relapse of overjet was associa ted with relapse of molar, premolar, and canine relationships, postret ention increase in overbite, postretention proclination of maxillary i ncisors, and postretention retroclination of mandibular incisors. Acti ve treatment changes included redirection or inhibition of maxillary g rowth and retraction of maxillary incisors. Mandibular incremental gro wth was favorable both during and after treatment. It was concluded th at successful correction of Angle Class II, Division 1 malocclusions t hrough differential growth adaptation and tooth movement appears to be very stable.