Clinical Feasibility and Skeletal Effects of Digitally Guided Supragingival Miniplates for Herbst Therapy in Late...

Background: Conventional Herbst appliances are effective for the correction of skeletal Class II malocclusion, but they are frequently associated with dentoalveolar side effects, particularly lower incisor proclination. Skeletal anchorage systems may improve orthopedic outcomes; however, submucosal miniplates require invasive surgical procedures that may reduce patient acceptance. This pilot clinical study evaluated the feasibility, safety, and skeletal effects of a minimally invasive digitally guided protocol using supragingival miniplates for bone-supported Herbst therapy in late adolescents. Methods: Eleven late-adolescent patients (14-17 years; cervical vertebral maturation stages CS4-CS5) with skeletal Class II malocclusion due to mandibular retrusion were prospectively treated using a bone-supported Herbst appliance anchored to digitally planned supragingival stainless-steel miniplates fixed with bicortical miniscrews. Miniscrew placement was planned by merging CBCT and intraoral scan data and performed using 3D-printed surgical guides. Cephalometric variables, including SNA, SNB, Wits appraisal, mandibular plane angle, and incisor inclinations, were assessed before treatment and after a 10-month Herbst phase. Mandibular advancement was additionally explored using a complementary linear measurement (SeMndb-line). Results: All patients completed treatment without anchorage loss, appliance failure, or surgical complications. Significant skeletal improvements were observed, including an increase in SNB (+3.36°, p < 0.001) and a reduction in Wits appraisal (-2.65 mm, p < 0.001). The SeMndb-line increased by +3.49 mm (p < 0.001), supporting effective mandibular advancement. Lower incisor inclination remained stable (Δ = -0.18°, p = 0.909), indicating effective dentoalveolar control. No clinically relevant changes in vertical skeletal pattern were observed. Conclusions: Digitally guided supragingival miniplates for bone-supported Herbst therapy appear to be a feasible and minimally invasive approach for the treatment of skeletal Class II malocclusion in late adolescents. This protocol achieved clinically meaningful mandibular advancement while minimizing dentoalveolar side effects. Given the pilot design, small sample size, and lack of a control group, further controlled studies with larger samples and long-term follow-up are required.