Computer-guided minimally invasive sinus augmentation with the Hiossen OneCAS system: a case report.

Implant placement in the posterior maxilla is often limited by insufficient bone height. This report demonstrates a minimally invasive, guided crestal sinus augmentation using the Hiossen OneCAS hydraulic system. A 74-year-old woman presented with a nonrestorable maxillary molar. Extraction, ridge preservation, and guided crestal sinus augmentation were performed using the Hiossen OneCAS system. Implants were simultaneously placed at the molar and premolar sites with successful osseointegration and prosthetic rehabilitation. The guided approach minimized complications and achieved favorable stability and esthetic outcomes despite limited crestal bone height (4.02 mm). The Hiossen OneCAS system represents a feasible, minimally invasive approach for guided hydraulic sinus elevation and implant placement in atrophic posterior maxillae, reducing surgical morbidity while supporting prosthetically driven accuracy. Long-term prospective studies are needed to establish predictability and functional outcomes. (Quintessence Int 2026;57:766-773; doi: 10.3290/j.qi.b7068655).