This consecutive retrospective study compared Mini-implant Assisted Slow Palatal Expansion (MASPE) with rapid palatal expansion (MARPE) using a bone-borne skeletal expander in adults with a narrow maxilla. CBCT scans analyzed transverse changes and potential pterygoid process deformation before (T1) and after expansion (T2). The Force Controlled PolyCyclic (FCPC) SLOW palatal expansion group (FCPC-MASPE-G) comprised 35 adults aged 18–54 years and received a skeletal expander limiting expansive force only allowing 500 cN at the activation wrench (force control). Discontinuous, polycyclic activations according to the FCPC-protocol were applied. The MARPE-group (n = 6) underwent continuous RAPID activation without FCPC until the desired width was reached. CBCT scans were taken pre and post-expansion. Inclusion criteria for both groups were successful outcomes without surgical assistance. The maxilla opened transversally in both groups mildly V-shaped, with a pyramidal shape in the coronal plane, impacting the zygomatic bone. Width measurements at T2 indicated superior mechanical response in FCPC-MASPE-G. Response of zygomaticomaxillary sutures was similar in both groups (p < 0.001 to 0.025). Pterygoid process deformations were notably less in FCPC-MASPE-G (0.87–1.35 mm, p < 0.001) compared to MARPE-G (2.70–3.04 mm, p < 0.001 to 0.009). Dental measurements were similar (p < 0.001 to 0.023), but the ratio “Mid-palatal suture Opening Related to Expander opening” (M.O.R.E.-factor) was better with 84% in FCPC-MASPE-G than with 50% in MARPE-G. Slow expansion with FCPC protocol effectively widens the maxilla in adults, with significant impact on bones and sutures and less pterygoid process deformation compared to rapid expansion. Cranial complications were absent in both groups.

Background: Management of skeletal Class III malocclusion of maxillary origin in late adolescence remains challenging, as conventional tooth-borne orthopedic approaches show reduced effectiveness at advanced stages of skeletal maturation. Minimally invasive, bone-anchored alternatives supported by digital workflows may improve clinical feasibility and patient acceptance. Objective: To describe a digitally guided clinical protocol combining a hybrid maxillary expander and supragingival mandibular miniplates, and to explore skeletal and dentoalveolar outcomes in late adolescents. Methods: This retrospective pilot clinical study included ten late adolescents (mean age 16.0 ± 1.3 years; range 13.8–17.7) in advanced skeletal maturation stages (CS4–CS6) with skeletal Class III malocclusion of maxillary origin. Treatment consisted of a hybrid maxillary expander anchored to palatal miniscrews and custom supragingival mandibular miniplates, placed using a fully digital workflow. Maxillary protraction was performed using a modified Alt-RAMEC protocol followed by continuous intermaxillary elastic traction for 12 months. Pre- and post-treatment cephalometric analyses were conducted. Results: A significant increase in SNA was observed (mean +6.1°, p < 0.001), indicating forward maxillary displacement. The Wits appraisal improved by 3.3 mm (p = 0.007), and the SeMax increased by 2.9 mm (p = 0.0013). No significant changes were found in the SNB or mandibular plane angle. Dentoalveolar effects were limited. Conclusions: Within the limitations of this pilot clinical study, the proposed digitally guided protocol demonstrated clinically relevant maxillary advancement with minimal dentoalveolar side effects and preserved vertical control. This relatively minimally invasive approach compared to conventional subgingival miniplates and orthognathic surgery may represent a feasible treatment option for selected late adolescent patients. Further controlled studies are required to confirm these findings.

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.