Assessment and localization of the posterior superior alveolar artery in lateral window approach for maxillary sinus floor elevation

Abstract Background Maxillary sinus (MS) floor elevation using the lateral window approach is a predictable technique for bone augmentation in the posterior maxilla. However, injury to the posterior superior alveolar artery (PSAA) during osteotomy can result in significant intraoperative bleeding and compromise surgical visibility. This study aimed to evaluate the presence, anatomical location, and vertical distance of the PSAA using cone-beam computed tomography (CBCT) and to analyze its relationship with the vertical position of the simulated lateral window relative to the sinus floor, relevant to sinus floor elevation procedures. Methods A retrospective observational analysis was performed on 1152 MS assessed on CBCT scans obtained for various diagnostic purposes. Scans fully visualizing the MS and lateral wall were included. The PSAA was identified and classified according to its anatomical location: intraosseous, submucosal, or extraosseous. The vertical distance between the artery and the sinus floor was measured, and the vertical position of the simulated lateral window relative to the sinus floor was categorized into four classes (0–3 mm, 3–8 mm, 8–11 mm, and > 11 mm). Descriptive statistics were used to summarize the distribution of PSAA visibility, anatomical location, and lateral window height classes. Associations between PSAA anatomical location and vertical window position were examined using the Chi-square test for independence. Results The PSAA was identified in 68.1% of evaluated MS and was more frequently visible in males than in females. The artery was most commonly located beneath the Schneiderian membrane (48.6%), followed by intraosseous (17.6%) and extraosseous (1.8%) courses. The mean distance from the sinus floor was 8.3 ± 4.3 mm. Higher vertical positions of the simulated lateral window were significantly, although weakly, associated with an intraosseous arterial course. Conclusions The PSAA is identifiable on CBCT in approximately two-thirds of MS, most commonly following a submucosal course, with a mean distance of 8.3 mm from the sinus floor. PSAA location was significantly associated with the vertical position of the simulated lateral window relative to the sinus floor, supporting the value of CBCT-based anatomical assessment for preoperative lateral window planning in MS floor elevation procedures.