(1) Background: The aim was to perform a literature review on customized subperiosteal implants (CSIs) and provide clinical guidelines based on the results of an expert consensus meeting held in 2023. (2) Methods: A literature search was performed in Pubmed (MEDLINE) in July 2023, including case series and cohort studies with a minimum follow-up of 6 months that analyzed totally or partially edentulous patients treated with CSIs. Previously, an expert consensus meeting had been held in May 2023 to establish the most relevant clinical guidelines. (3) Results: Six papers (four case series and two retrospective cohort studies) were finally included in the review. Biological and mechanical complication rates ranged from 5.7% to 43.8% and from 6.3% to 20%, respectively. Thorough digital planning to ensure the passive fit of the CSI is mandatory to avoid implant failure. (4) Conclusions: CSIs are a promising treatment option for rehabilitating edentulous patients with atrophic jaws; they seem to have an excellent short-term survival rate, a low incidence of major complications, and less morbidity in comparison with complex bone grafting procedures. As the available data on the use of CSIs are very scarce, it is not possible to establish clinical recommendations based on scientific evidence.

(1) Background: The present study was carried out to provide a state-of-the-art review of the prosthodontic factors related to customized subperiosteal implants (CSIs), and to offer clinical guidelines in this regard. (2) Methods: An expert consensus meeting was held in July 2024 in Santpedor (Manresa, Spain) to establish the most relevant clinical guidelines. (3) Results and (4) Conclusions: An interdisciplinary approach including surgeons, prosthodontists, bio-medical engineers and dental technicians, integrating both biological and mechanical considerations when designing CSI rehabilitations, is very important. While the reported survival rate of CSIs appears promising, their long-term performance beyond 5 years remains insufficiently documented. Thus, CSIs are a viable treatment option for patients with insufficient bone to place conventional implants, but there is a clear need to identify and analyze delayed-onset complications associated with these devices. The findings and their broader implications should be thoroughly examined, and potential future research directions should be highlighted.