DOI: 10.11607/prd.2644, PubMed ID (PMID): 27100802Pages 328-337, Language: EnglishUrban, Istvan A. / Monje, Alberto / Nevins, Myron / Nevins, Marc L. / Lozada, Jamie L. / Wang, Hom-LaySevere vertical ridge deficiency in the anterior maxilla represents one of the most challenging scenarios in bone regeneration. Under ideal circumstances, guided bone regeneration in combination with soft tissue management has shown predictable esthetic and functional outcomes. Success largely relies on primary wound closure during and after the surgical procedure. Surgical sites present different challenges that need to be considered when designing the flap. The goal of this article is to propose a classification of flap designs that considers vestibular depth and scar formation around the periosteum when performing vertical ridge augmentation in the atrophic anterior maxilla. The four clinical conditions proposed under this classification are (1) shallow vestibule with healthy periosteum, (2) deep vestibule with healthy periosteum, (3) shallow vestibule with scarred periosteum, and (4) deep vestibule with scarred periosteum. The classification will allow clinicians to achieve tension-free closure and more predictable vertical bone gain.