Clinical Soft Tissue Adaptation to Biomechanical Modulation with the Bone Protection System (BPS): A Two-Case Report in Thin-Biotype Patients

<b>Background:</b> Patients with a thin gingival phenotype and a narrow buccal alveolar plate are highly susceptible to periodontal complications during orthodontic expansion. Traditional biomechanics often fail to maintain root control in thin alveolar housing. This report presents two clinical cases illustrating soft- and hard-tissue responses to a novel biomechanical approach, the Bone Protection System (BPS), designed to reduce buccal cortical overload during expansion. <b>Case Presentation:</b> Two adult patients with a thin gingival phenotype assessed by a standardized periodontal probe transparency test and narrow alveolar ridges underwent orthodontic expansion. Patient 1 was treated with the full BPS protocol in both arches. Patient 2 received BPS only in the maxilla, while the mandible was treated conventionally, creating an intra-individual control model under identical systemic conditions. Soft-tissue phenotype and cortical plate response were evaluated clinically and radiographically when applicable. <b>Results:</b> In Patient 1 clinically, the vestibular phenotype showed clear thickening and stabilization. In Patient 2, the maxillary arch treated with BPS exhibited progressive thickening of the vestibular phenotype, whereas the mandible treated conventionally presented thinning and increased translucency-features consistent with buccal compression in thin alveolar bone. No soft- or hard-tissue augmentation procedures were performed in either case. <b>Conclusions:</b> The Bone Protection System may contribute to improved periodontal safety during orthodontic expansion in thin-biotype patients by reducing buccal cortical loading and supporting adaptive soft-tissue and bone responses. Preliminary observations suggests that BPS has potential value for possibly expanding the biological limits of safe tooth movement. Further studies on larger cohorts are warranted.