Alveolar Bone Response to Controlled Orthodontic Maxillary Incisor Vestibularization

Abstract

1.Background/Objectives: Orthodontic proclination of retroclined maxillary incisors is frequently required for functional and esthetic correction; however, excessive movement may exceed the biological limits of the alveolar housing and compromise periodontal health. Understanding alveolar bone remodeling in response to controlled incisor vestibularization is essential for safe orthodontic planning. This study aimed to evaluate changes in labial and lingual alveolar bone thickness (ABT) assocoated with maxillary incisor proclination and to correlate these changes with dental movements and skeletal stability. 2.Methods: Nineteen patients presenting with retroclined maxillary incisors underwent orthodontic treatment involving controlled incisor vestibularization. Cephalometric and CBCT-derived measurements were standardized using the SN–7° reference plane and perpendicular orientation to the incisor long axis (⊥U1). ABT was assessed at the cementoenamel junction, 3 mm, and 6 mm apical levels on both labial and lingual surfaces. Dental and skeletal parameters including U1–SN, U1–NA, L1–NB, and SN–MP were recorded pre- and post-treatment. Paired statistical comparisons were performed. 3. 3. Results: Maxillary incisor proclination increased significantly, as demonstrated by substantial rises in U1–SN and U1–NA values. Labial alveolar bone thickness showed significant increases at mid-root and apical levels, indicating adaptive bone apposition on the tension side. In contrast, lingual ABT decreased significantly at corresponding levels, reflecting pressure-side resorption. No significant changes were observed in skeletal parameters, confirming predominantly dentoalveolar effects. Crestal bone thickness remained stable, suggesting a low periodontal risk. 4. Conclusions: Controlled vestibularization of retroclined maxillary incisors induces predictable alveolar remodeling characterized by labial bone apposition and lingual resorption without compromising skeletal balance or crestal periodontal support. When performed within biological limits, incisor proclination appears to be a safe and effective orthodontic strategy.