Comparison of Class II Correction with Elastics versus Mandibular Advancement in Growing Patients Using Clear Aligner Therapy

Objectives: This study aimed to compare the skeletal and dental changes, efficiency, and side effects of Class II correction in growing patients using clear aligners with Class II elastics compared to mandibular advancement (MA). Materials and Methods: A total of 66 growing Class II patients were included in this study. 20 patients were treated with Class II elastics, 25 patients were treated with MA, and 21 subjects were untreated Class II subjects. 9 cephalometric measurements and 3 study cast measurements were evaluated at initial (T1) and end of treatment (T2). Results: No significant differences were shown at T2 between the elastic and MA groups, indicating similar treatment outcomes for all variables. Final molar relationship and overjet for the control group demonstrated a Class II relationship while the elastic and MA groups corrected to a Class I relationship. Skeletal changes from T1 to T2 in the MA group, with reduction in SNA (-1.09°) and ANB (-1.69°), demonstrated a “headgear effect” in addition to dentoalveolar Class II correction. However, the elastics group demonstrated solely dentoalveolar correction. Linear regression revealed significant lower incisor proclination of 5.28° as a result of treatment with Class II elastics while lower incisor proclination was maintained with MA treatment. Conclusions: Clear aligner treatments with Class II elastics and MA are effective at correcting Class II malocclusions in growing patients that would have otherwise been maintained without intervention. Class II correction occurred primarily through dentoalveolar changes, although there was a skeletal component with MA treatment.