Efficacy of Class II correction with clear aligner therapy and intermaxillary elastics in adolescent patients: A retrospective study

INTRODUCTION: The aim was to assess the changes in overjet and the intermaxillary sagittal first permanent molar (FPM) relationship in adolescent patients after treatment with an initial series of Invisalign (Align Technology, San Jose, Calif) aligners and Class II elastics. METHODS: Patients satisfying the inclusion and/or exclusion criteria were selected from a database of patients treated by 18 orthodontists. Data were extracted from Align Technology's software facility related to demographic information and pretreatment, planned, and posttreatment overjet values. Metrology software was used to determine changes in the intermaxillary sagittal FPM relationships. RESULTS: The mean (standard deviation) age of the 199 patients who satisfied selection criteria was 13.7 (2.1) years. Most were female (132 [66.3%]), and the mean overjet reduction was 33.95% of the planned reduction. The overjet of 62 (31.2%) patients was greater at the end of the prescribed aligner and Class II elastic wear, despite a planned reduction. The pretreatment sagittal FPM relationship reduced from a mean (standard deviation) of 2.53 (1.72) mm to 1.18 (1.97) mm, which corresponded to 45.91% of the planned change. The achieved outcome was in the opposite direction relative to that planned in 24 (12.06%) left FPMs and 24 (12.06%) right FPMs. Distalization appeared to be more efficacious (P <0.05) than the jump and en masse methods for sagittal correction of the FPM relationship. CONCLUSIONS: Approximately one-third of the planned overjet reduction and just less than half of the planned intermaxillary sagittal FPM changes were achieved with an initial series of Invisalign aligners and Class II elastics in a sample of adolescent patients.