The incisal edge of the maxillary central incisor is ideally positioned 8-10 mm anterior to the incisive papilla because the incisive papilla serves as a stable anatomical landmark that remains unchanged after tooth extraction. This measurement ensures proper aesthetic alignment and functional occlusion when fabricating complete dentures or planning prosthetic rehabilitation. Maintaining this distance helps in replicating the natural tooth position, supporting lip contour and phonetics effectively. Incorrect positioning can lead to impaired esthetics and articulation.

Reference: Prosthodontics: Principles and Management Strategies, Deepak Nallaswamy, 2nd Edition.