Incisor Inclination Revisited: A Proposed Structural Compatibility Framework for Individualized Treatment Planning

Background: Cephalometric reference values describe incisor orientation but do not establish whether the root movement required to achieve them is appropriate for an individual alveolar housing. Objectives: This study aimed to propose a structural compatibility framework in which cephalometric normalization is a conditional treatment objective for permanent maxillary and mandibular incisors. Materials and Methods: A narrative conceptual analysis integrated published anatomical, cephalometric, and biomechanical evidence. The framework combines intended movement with root orientation, root position, alveolar dimensions, cortical clearance, and maxillary root–incisive canal relationships. No patient-level measurements or clinical validation were performed. Results: The conceptual synthesis distinguishes selecting an angular target from assessing the root trajectory needed to reach it. Axis discordance (Δθ) is retained as a candidate orientation descriptor, not an independent measure of biological risk. Existing anatomical measurements are organized to identify potential conflicts between angular correction and local structural constraints. Conclusions: Achieving a cephalometric reference value should not, by itself, be interpreted as biological improvement. The proposed framework makes the reconciliation of angular objectives, root trajectory, and tissue preservation explicit. Measurement reliability, added value over existing assessment, and clinical benefit require separate evaluation.