Patient-Specific Subperiosteal Implants in the Rehabilitation of the Severely Atrophic Maxilla: A Clinical Series

Alveolar bone morphology plays a key role in the rehabilitation of the edentulous patient. In the presence of teeth, mechanical compression and muscle function help maintain bone. In edentulism, maxillary resorption follows a centripetal trajectory, leading to a narrower maxilla and a prosthetically-unfavorable pseudo-class III ridge relationship. Longer durations of edentulism, especially in the context of poorly fitting dentures, can yield severely atrophic maxillae. Rehabilitation of atrophic maxillae remains a challenge, as standard endosseous implants usually require extensive grafting. The quad zygoma approach may be considered, but require high surgical skill and carry risk of sinus complications. Additively-manufactured subperiosteal implants offer an immediate fixed solution for patients exhibiting Cawood and Howell class V-VI bone atrophy, for whom conventional solutions have failed or are contraindicated. We present two patients who have received patient-specific, prosthetically-driven subperiosteal implants with immediate provisionalization (IPS Preprosthetic, KLS Martin). Cone-beam computed tomography (CBCT) and computer-aided design (CAD) are used to redefine a controversial 70-year-old concept, using prosthodontic reverse-engineering to offer added stability, reduced morbidity, improved patient satisfaction, and minimized sinus complications.