Treatment effects of a twin-force bite corrector versus an activator in comparison with an untreated Class II sample: a preliminary report.

Abstract

The present study aimed to compare the treatment outcomes of a fixed-functional appliance (Twin-Force Bite Corrector - TFBC) and a conventional removable functional appliance (Activator) in the treatment of skeletal Class II malocclusions. The TFBC and Activator Groups each included 10 young adults possessing a skeletal Class II malocclusion, and the treatment outcomes of both groups were quantified and compared, using lateral cephalometric radiographs, with an untreated skeletal Class II Control Group. A skeletal Class I relationship and a marked reduction in overjet were achieved in both treatment groups; however, the duration of treatment was significantly shorter in the TFBC Group (0.45 years) when compared with the Activator Group (1.37 years) (p < 0.001). Effective length and sagittal positioning of the mandible underwent significant changes in the TFBC and Activator Groups. Vertical facial dimensions increased in each group; however, these increases were significantly greater in the Activator Group when compared to the TFBC and Control Groups (p < 0.05). Dentoalveolar changes also contributed to the reduction in overjet. Although both appliances succeeded in eliminating the Class II relationship and improving the overjet and overbite, the short treatment time in the TFBC Group raises questions regarding the long-term stability of the results.