The PATZi Protocol for Full-Arch Rehabilitation of the Atrophic Maxilla: A Narrative Review of the Literature

Immediate, graftless full-arch rehabilitation of the atrophic maxilla is constrained by alveolar resorption, sinus pneumatization and poor posterior bone quality, and conventional four-implant configurations may end in a shortened dental arch, a long distal cantilever or an unplanned change of strategy during surgery. The PATZi protocol (Pterygoid, Anterior, Tilted, Zygomatic implants) was proposed in 2023 as a stepwise algorithm that sequences implant techniques by maxillary region, prefers the least invasive option in each region, reserves zygomatic implants for regions in which no other anchorage can be obtained, and codes each configuration to grade complexity and plan salvage. This narrative review outlines the protocol and appraises the evidence for each of its components. Systematic reviews report cumulative survival of roughly 92–96% for pterygoid implants, survival of tilted implants equivalent to that of axial implants and mean survival of 97% for zygomatic implants, whereas nasopalatine and transnasal anchorage rest largely on small series and case reports. Evidence on the protocol itself is limited to its original description, a one-year cohort of 142 immediately loaded arches with a Full-Arch Ratio of 94, a 2025 extension to the moderately atrophic maxilla and one case report. PATZi is a coherent, prosthetically driven framework, but prospective comparative studies with long-term follow-up are needed to establish its outcomes.