Clinical and Radiographic Evaluation of Direct and Indirect Maxillary Sinus Lift Procedures in Partially Edentulous Posterior Maxilla: A Comparative Study

Abstract

Background: In the edentulous posterior maxilla, alveolar bone resorption and maxillary sinus pneumatization reduce bone height and density, complicating implant placement and often necessitating sinus augmentation.

Aim: This study aimed to compare the clinical, radiological, and patient-centred outcomes of direct (lateral window) and indirect (crestal/osteotome) maxillary sinus lift techniques for implant placement.

Materials and Methods: Fifty-six patients with insufficient posterior maxillary bone height were randomly assigned to two groups (n = 28 each). Clinical outcomes, radiographic bone gain, implant stability, and survival were assessed over 12 months.

Results: The lateral window technique achieved significantly greater vertical bone gain (6.5 ± 1.3 mm) than the crestal approach (4.2 ± 1.0 mm; p < 0.001), with higher insertion torque and superior secondary stability at 6 months. Primary stability at placement and implant survival rates were comparable between groups (98.2%). Postoperative pain and swelling were slightly higher with the lateral approach but resolved within one week. Membrane perforation was more frequent in the lateral group (10.7% vs. 3.6%) without long-term consequences. Conclusion: The lateral window approach provides greater bone gain and implant stability in severely resorbed posterior maxillae, while the crestal technique offers a minimally invasive alternative with lower morbidity and comparable long-term implant success in moderate cases. An individualized, anatomy-based approach is recommended for optimal outcomes.