Implant Overdentures in Atrophic Maxilla: Review of Zygomatic and Tilted Implant Protocols

The rehabilitation of the atrophic maxilla presents a significant clinical challenge due to the limited availability of bone and anatomical constraints. Traditional approaches often involve bone grafting or sinus augmentation. However, zygomatic and tilted implant protocols have emerged as graftless alternatives that simplify treatment and reduce morbidity. This narrative review aims to evaluate the clinical outcomes, indications, surgical complexity, and complication profiles associated with tilted and zygomatic implant protocols used in implant overdenture rehabilitation of the atrophic maxilla. A comprehensive literature search was conducted using PubMed, Scopus, and Google Scholar. Peer-reviewed studies published in English from 1990 to 2025 were included, focusing on clinical trials, cohort studies, systematic reviews, and case series relevant to zygomatic and tilted implants. The review synthesizes data on survival rates, complications, and prosthetic outcomes. A total of 32 studies were reviewed. Tilted implants, including the All-on-4 concept, demonstrated survival rates of 92–98% and were primarily indicated for moderate atrophy. Zygomatic implants showed survival rates of 95–100%, providing a viable solution for severe maxillary resorption. Complication profiles varied: tilted implants were associated with prosthetic issues, while zygomatic implants posed higher surgical risks such as sinusitis and paresthesia. Both tilted and zygomatic implants offer successful graftless rehabilitation options for atrophic maxillae. Case selection based on anatomical and biomechanical considerations is essential. Further randomized controlled trials are needed to directly compare these protocols in overdenture-based rehabilitation settings.