Fixed functional appliances are non-compliance dependent devices, which can assist the correction of Class II malocclusion. The mechanics of the fixed functional appliances may vary depending on the type of device used. We report the observed biomechanical effects of using the ForsusTM Fatigue Resistant Device (FRD) fixed functional appliance. The patient was a 14-year-old female presented with a Class II division I malocclusion on a Class II skeletal base. The malocclusion was complicated by a 10mm overjet and increased traumatic overbite. She was treated with the ForsusTM FRD appliance worn for 5 months after the alignment with fixed appliances (0.022” X0.028” MBT prescriptions) and finished on a non-extraction base. Dento-alveolar changes were the main contribution to the correction of the malocclusion and simultaneously improved the patient’s profile in the end of treatment. In conclusion, ForsusTM FRD appliance can be suggested to effectively correct Class II malocclusion.