Novel use of amnion-chorion membrane in managing sinus membrane perforations during crestal sinus augmentation: The waffle cone technique.

Background: Crestal sinus augmentation is a minimally invasive approach used to increase vertical bone height in the posterior maxilla. Compared with the traditional lateral window technique, the crestal approach reduces surgical morbidity, postoperative discomfort, and overall treatment time, while still providing the ability to regenerate sufficient bone for implant placement. Despite these advantages, a major challenge of this technique is the difficulty in detecting and managing Schneiderian membrane perforations due to limited visual access. Schneiderian membrane perforation remains the most frequent complication associated with sinus augmentation and, if left unmanaged, may compromise graft stability, increase the risk of sinus pathology, and negatively affect implant survival. Therefore, the development of reliable methods to identify and manage membrane perforations is critical for achieving predictable outcomes. This case series aims to describe a novel approach for managing sinus membrane perforations encountered during crestal sinus augmentation using amnion-chorion membrane. The technique involves the application of amnion-chorion membranes to seal perforations, allowing simultaneous bone grafting and implant placement.

Methods: Patients presenting with posterior maxillary edentulism and insufficient vertical bone height were treated using the crestal sinus augmentation technique assisted by osseodensification drills. Clinical and radiographic outcomes were systematically evaluated. Preoperative assessment included measurement of the residual alveolar bone height and determination of the sinus floor angle. Each sinus was carefully examined radiographically to rule out any pre-existing pathology, such as mucosal thickening, cystic changes, or evidence of sinusitis. Intraoperative sinus membrane perforations were identified during osteotomy preparation. Management involved the placement of dehydrated amnion-chorion membrane configured in a "waffle cone" shape, which allowed simultaneous implant placement and bone grafting in all cases. The amount of vertical lift achieved was also measured postoperatively to quantify the effectiveness of the crestal sinus augmentation and to ensure adequate bone gain for implant placement. At the 2-year follow-up, both clinical and radiographic evaluations were repeated to assess implant stability, peri-implant bone levels, sinus architecture, and maintenance of the augmented height, thereby confirming the long-term success of the intervention.

Results: All cases demonstrated successful sealing of the Schneiderian membrane using the amnion-chorion membrane, with successful simultaneous implant placement. Immediate postoperative radiographs and cone-beam computed tomography confirmed stable graft containment with average of 5.2 mm vertical sinus lift. After a healing period of 6 months, all implants achieved successful osseointegration. At the 2-year follow-up, periapical radiographs revealed stable peri-implant bone levels with no radiographic or clinical signs of sinus complications.

Conclusion: The use of amnion-chorion membranes in a "waffle cone" configuration provides a simple and effective method for repairing Schneiderian membrane perforations encountered during crestal sinus augmentation. This technique enables simultaneous implant placement and grafting, expanding the scope of minimally invasive sinus augmentation procedures in compromised sites.

Key points: Predictable repair and graft containment: The technique described in this case series offers a predictable method for managing Schneiderian membrane perforations that occur during crestal sinus augmentation. By placing an amnion-chorion membrane in a "waffle cone" configuration, clinicians can achieve stable graft containment and secure defect coverage. This approach provides an effective biologic barrier that supports simultaneous bone grafting and implant placement, thereby maintaining surgical efficiency while minimizing the risk of graft migration or sinus complications. Favorable long-term outcomes: Clinical and radiographic evaluations at the 2-year follow-up demonstrated consistent membrane repair, predictable bone regeneration, and stable peri-implant bone levels, with all implants achieving successful osseointegration. These results align with recent evidence indicating that small, well-managed sinus membrane perforations do not negatively affect implant survival or regenerative outcomes. The findings further support the long-term predictability of biologically based repair strategies in crestal sinus augmentation. Clinical relevance and practicality: This technique reduces the need for staged procedures, lowers surgical morbidity, and enhances overall treatment efficiency. From a clinical perspective, it is particularly relevant for periodontists and implant surgeons, as it transforms a common intraoperative complication into a manageable event that does not compromise long-term success. By incorporating biologically active membranes such as amnion-chorion into the management protocol, clinicians can expand the safety and applicability of the crestal sinus lift technique, even in anatomically challenging cases.

Plain language summary: When placing dental implants in the upper back jaw, there is often not enough bone height to hold the implants securely. A common way to solve this is by gently lifting the sinus floor and adding bone graft material through a small opening in the bone (called a "crestal sinus lift"). One of the main risks with this procedure is tearing the sinus lining, which can make treatment more difficult and increase the chance of complications. In this report, we describe a new method for repairing these tears using a thin, biologic material called an amnion-chorion membrane, folded into a "waffle cone" shape. This simple technique seals the tear and keeps the bone graft in place, while also allowing the implant to be placed at the same time. All patients in this study healed well. At the 2-year follow-up, the implants were stable, the bone levels were preserved, and no sinus problems were seen. This technique gives dentists a predictable and minimally invasive way to manage sinus tears and successfully place implants in areas with limited bone.