Comparison of the effects of Forsus and CS5 system fixed functional appliances on dentofacial structures in the late treatment of class II malocclusion

This study compared the skeletal, dentoalveolar, and soft tissue effects of the Forsus appliance and the CS5 System fixed functional appliance in post-pubertal patients with Class II malocclusion due to mandibular retrognathia. The sample consisted of 40 subjects, divided into two equal groups. Pre- and post-treatment lateral cephalometric radiographs were analysed using angular and linear parameters. Both appliances restricted maxillary forward growth, advanced the mandible, and significantly improved sagittal intermaxillary relationships. The reduction in ANB angle was greater in the Forsus group. Effective mandibular length (Co–Gn) increased significantly in both groups, whereas effective maxillary length (Co–A) decreased only in the CS5 group. Upper incisor retrusion and lower incisor protrusion were observed with both appliances, with Forsus producing greater proclination of the mandibular incisors. Overjet and overbite decreased significantly in both groups, with Forsus showing larger reductions. Moreover, a significant decrease in U6–PP angle was detected in the Forsus group, indicating maxillary molar uprighting. Regarding soft tissue, both appliances increased the nasolabial angle and caused upper lip retrusion, which was more pronounced in the Forsus group. In conclusion, both the Forsus appliance and the CS5 System were effective in correcting Class II malocclusions. Forsus demonstrated stronger dentoalveolar effects, while the CS5 System provided advantages in terms of patient comfort and clinical applicability as a viable alternative. Keywords: Class II malocclusion, Forsus appliance, CS5 System, fixed functional appliance, cephalometry