Large Schneiderian Membrane Perforation Repair During Sinus Lift Surgery: A Case Report

Background: Maxillary sinus floor elevation is a predictable procedure for implant rehabilitation in the posterior maxilla with reduced residual bone height. Schneiderian membrane perforation is the most frequent intraoperative complication during sinus lift surgery and may compromise graft stability and treatment outcomes. Stabilized collagen membrane techniques have been proposed to manage extensive perforations. Objective: The aim of this study was to describe the management of a large Schneiderian membrane perforation (>10 mm) using a stabilized collagen membrane technique and to evaluate the clinical outcome. Case Description: A 67-year-old male patient (ASA I, non-smoker) with insufficient posterior maxillary bone height underwent lateral window sinus augmentation. During membrane elevation, a large perforation (>10 mm) occurred. A resorbable collagen membrane was adapted and stabilized to isolate the defect and create a contained compartment for graft placement. A xenograft was inserted, and an additional collagen membrane was used to cover the lateral window and stabilized with fixation pins. Primary closure was achieved with tension-free sutures. Results: Healing was uneventful, without sinus pathology or postoperative complications. Radiographic evaluation confirmed graft stability and adequate volume maintenance. Implant placement was successfully performed after 6 months, achieving satisfactory primary stability and favorable clinical outcomes after one year of loading. Conclusion: In this case, the stabilized collagen membrane technique allowed successful management of a large Schneiderian membrane perforation, enabling continuation of sinus augmentation, successful graft containment, and favorable implant rehabilitation outcomes.