Anterior alveolar anatomical constraints involving presurgical orthodontic incisor repositioning are often unrecognized and overlooked during orthodontic-surgical treatment planning. A clear discrimination of this cortical limitation is invaluable during the planning stage as it permits the consideration of alternative approaches like the anterior maxillary osteotomy for effecting the required incisor movement. A simple reference line termed the "Cortical Boundary Line" is introduced to facilitate the clinical translation of this information and through suitable case illustrations, the construction of the reference line using the conventional lateral cephalometric radiograph and its usefulness as an adjunct in aiding decisions on orthodontic incisor decompensation is highlighted.