Indications and Complications of Subperiosteal Implants: Literature Review and Case Series

Background/Objectives: Severe jawbone atrophy, particularly in elderly or medically compromised patients, presents a significant challenge for conventional implant placement. In cases where bone augmentation is not feasible, alternative techniques-such as short, narrow, tilted, and zygomatic implants-may be indicated for the rehabilitation of the atrophic jaw. Subperiosteal implants have re-emerged as a further viable alternative, especially with recent advancements in digital planning and custom fabrication. This study aims to evaluate the clinical outcomes and complications associated with subperiosteal implants through a literature review and a supporting case series, and to propose clinical preliminary guidelines for their use. Methods: Fourteen studies-including case reports, case series, retrospective studies, and systematic reviews-were analyzed to assess the effectiveness and risk profile of subperiosteal implants. Additionally, we present a case series of nine patients with advanced vertical and horizontal alveolar bone atrophy treated using custom-made, digitally-designed subperiosteal implants. Surgical techniques, prosthetic workflows, and complications were recorded and assessed. Results: Subperiosteal implants were found to be particularly suitable for patients with narrow alveolar crests and severe atrophy where traditional implants are contraindicated. Literature and case series data indicated favorable outcomes, with early complications such as soft tissue inflammation and prosthetic misfit being manageable. A low complication rate was recorded in our series, with digital workflows contributing to improved implant fit and reduced technical errors. Conclusions: Subperiosteal implants could offer an effective solution for complex atrophic cases, provided that patient selection, surgical precision, and prosthetic design are meticulously managed. Based on our findings, clinical recommendations are proposed to guide their application in contemporary practice.