Severe atrophy of the maxilla occasionally renders it impossible to place standard endosseous implants to replace absent teeth. For such cases, personalized subperiosteal implants (PSI) are presented as a treatment alternative. Due to novel design and manufacturing technologies, PSIs are fitted closely to the bone structure of the patient, after defining the anchorage areas where the bone is of higher quality and allowing a passive dental prosthesis to be attached to restore function and aesthetics to the patient. The present case report documents a patient with severe bone defects as a sequela of rhino-orbit-cerebral mucormycosis. After a failed microvascular fibula flap reconstruction, the patient was treated with a removable implant-supported prosthesis attached to a PSI, which provided occlusion with the mandible of the patient and closed the oronasal-antral communication defect. At 18 months after treatment, the patient felt well, with no biological complications and the prosthesis was well adjusted and with good function. Consequently, we consider that in some cases such as this, a customized solution of this type can avoid complex reconstruction treatments.