Non-Surgical Correction Of Moderate-Severe Skeletal Class III Malocclusion

Class III skeletal malocclusion is often caused by craniofacial developmental abnormalities, and severe cases typically require orthognathic surgery in adulthood. This case demonstrates the use of Force-Transmission Mechanics (FTM), developed by Prof. Lin Jiu-Xiang’s team at Peking University School of Stomatology, for non-surgical orthodontic camouflage treatment. By applying force-transmission principles, the technique achieved coordination of maxillo-mandi A 14-year-old female presented with “underbite” and was diagnosed with severe Class III skeletal malocclusion (Wits: -11.7 mm, ANB: -4.2°), vertical growth pattern, anterior and posterior crossbite, mandibular deviation, and moderate crowding in both arches. Treatment involved extraction of teeth 38 and 48, followed by FTM therapy. After 3 years, crossbite was resolved, overjet and overbite were normalized, midlines were aligned, and facial aesthetics improved, achieving satisfactory camouflage results. Conventionally, this case would require orthodontic-surgical treatment. However, as the patient’s mandible could retract to edge-to-edge incisor relationship and non-surgical treatment was strongly requested, dental anchorage and light intermaxillary traction were used to correct sagittal jaw relationships. The treatment avoided mini-implants or extraoral forces. The low-friction, light-force (≤60g) design minimized risks of root resorption and bone dehiscence, aligning with the health-focused philosophy of FTM. FTM offers a reliable non-surgical solution for severe Class III malocclusion. Its light-force mechanics provide a replicable treatment paradigm for orthodontists, particularly for adolescent patients who reject or are unsuitable for surgery.