USES OF LATERAL BONE WINDOW REPOSITIONING TECHNIQUE IN MAXILLARY LATERAL SINUS ELEVATION: A CLINICAL AND RADIOGRAPHIC FOLLOW-UP STUDY FOR 121 PATIENTS FOR 30 TO 90 MONTHS.

Background: Maxillary lateral sinus elevation (LSE) is crucial for increasing vertical bone height in the posterior atrophic maxilla. It facilitates implant placement by creating adequate bone support. This case series describes the lateral bone window repositioning (WR) technique in LSE and evaluates its effectiveness in graft stabilization and clinical success through clinical and radiographic examination. Methods: This case series included 121 patients (151 sinuses) who met specific inclusion criteria. A total of 285 implants were placed: 150 (52.6%) implants were inserted simultaneously, while 135 (47.4%) were placed 4–6 months after the MLSE procedure. All cases were followed clinically and radiographically for 30 to 90 months. Preoperative cone beam computed tomography (CBCT) scans were taken for proper evaluation of the surgical site, and postoperative CBCT scans were performed 4–6 months after LSE. Patients underwent follow-up evaluations every six months for clinical implant assessment, and periapical images were taken annually to monitor marginal bone levels. The surgical protocol involved performing a beveled osteotomy using a piezoelectric device to create a bone lid. After removal, the Schneiderian membrane was elevated to manage space for the bone graft. The bone lid was then repositioned in its original place. Results: Among 151 LSE cases, 146 (96.7%) exhibited successful outcomes, with complete integration of the bone lid into the surrounding bone, confirmed through clinical and radiological examinations. Three failures were reported, one due to trauma and two resulting from sinus infections. Two cases were excluded due to bone window fractures during removal. Small perforations of the Schneiderian membrane occurred in 28 cases (18.5%), all successfully managed with collagen membranes. Conclusion: The WR technique in LSE demonstrated a high success rate, repeatable results, and effective graft integration, making it a viable option for vertical bone height augmentation.