From Twin Blocks to Quad Blocks: A Two-Phase Approach to Class II Correction

Twin Block, a functional orthodontic appliance, has a major impact on the dentoalveolar structures with limited skeletal effects. In specific clinical scenarios, particularly in growing patients such as class II division 1 where the mandible is retropositioned, these appliances can effectively address the malocclusions. Patient compliance plays a crucial role in the success of these appliances, which also streamline subsequent phases of fixed appliance treatment. In the current case report, a Twin Block appliance followed by a Quad Block was given to a 12-year-old boy to refine the occlusion. The design and treatment outcomes of the appliance are discussed in this case study.