Complications and management of modified custom-made subperiosteal implants in severely atrophic maxilla and mandible: a retrospective cohort of 211 implants.

Modified custom-made, additively manufactured subperiosteal implants incorporating guided crestal boneoplasty for abutment housing have re-emerged as a graftless option for selected patients with severe jaw atrophy. This study evaluated the incidence, timing, severity, and management of complications in a large consecutive cohort. A retrospective analysis was conducted on 124 patients who received 211 titanium custom-made subperiosteal implants between 2018 and 2025 at a single maxillofacial surgery unit. Indications included completely edentulous arches and segmental rehabilitation of atrophic edentulous regions where conventional endosseous implant placement was not feasible without major reconstructive procedures or unfavourable prosthetic compromises. All cases were digitally planned. Clinical and radiological records were reviewed to assess implant survival and intraoperative, early, and late biological or mechanical complications. The median follow-up was 28 months. The overall implant survival rate was 98.1%. Intraoperative and early postoperative complications were uncommon and mostly mild. Late biological events were dominated by limited framework exposure, recorded in 9.5% of implants, almost exclusively grade 1 and usually asymptomatic. A previously under-reported pattern of delayed, non-suppurative oedema was observed mainly in maxillary cases and was generally self-limiting or responsive to conservative treatment. Mechanical complications were rare, with no framework or fixation screw fractures and only two fractures of provisional prostheses. Modified custom-made subperiosteal implants may provide a predictable graftless rehabilitation option for selected patients with severely atrophic jaws, with high survival and a predominantly low-grade, manageable complication profile.