Evaluation of Maxillary Sinus Anatomy Using CBCT for Safe Sinus Lift Procedures

Abstract

Background:

Successful implant rehabilitation in the posterior maxilla requires a thorough understanding of maxillary sinus anatomy. Anatomical variations such as reduced residual alveolar bone height, Schneiderian membrane thickness, sinus septa, maxillary sinus pneumatization, and the course of the posterior superior alveolar artery (PSAA) may influence the safety and predictability of sinus floor elevation procedures. Cone-beam computed tomography (CBCT) provides three-dimensional visualization, enabling comprehensive preoperative assessment of these anatomical structures.

Aim:

To evaluate the anatomical characteristics of the maxillary sinus using CBCT and determine their clinical relevance for planning safe sinus floor elevation procedures.

Materials and Methods:

A retrospective observational study was conducted on CBCT scans of 60 adult patients (120 maxillary sinuses). Residual alveolar bone height, Schneiderian membrane thickness, maxillary sinus pneumatization, sinus septa, and PSAA visibility were assessed. Data were analyzed using Statistical Package for the Social Sciences (SPSS) Statistics version 26.0. Descriptive statistics were expressed as mean ± standard deviation (SD), standard error (SE), and 95% confidence intervals (CI). Independent-samples Student's t-test was used for group comparisons, Pearson's correlation coefficient assessed the relationship between residual bone height and sinus pneumatization, and binary logistic regression identified factors associated with reduced residual alveolar bone height. Statistical significance was set at p < 0.05.

Results:

The mean residual alveolar bone height was 5.82 ± 2.04 mm (95% CI: 5.45–6.19 mm), while the mean Schneiderian membrane thickness was 1.73 ± 0.61 mm (95% CI: 1.62–1.84 mm). Residual bone height was significantly lower in sinuses with extensive pneumatization than in those with mild-to-moderate pneumatization (4.68 ± 1.52 mm vs. 6.85 ± 1.74 mm; t = 7.21, p = 0.001). Schneiderian membrane thickness was significantly greater in sinuses with septa than in those without septa (1.94 ± 0.63 mm vs. 1.62 ± 0.58 mm; t = 2.71, p = 0.001). The PSAA was identified in 79.2% of the evaluated sinuses. A significant moderate negative correlation was observed between residual alveolar bone height and the degree of sinus pneumatization (r = −0.58, p < 0.001). Binary logistic regression demonstrated that extensive sinus pneumatization was an independent predictor of reduced residual alveolar bone height (OR = 3.12; 95% CI: 1.61–6.05; p = 0.001).

Conclusion:

CBCT provides valuable three-dimensional information regarding maxillary sinus anatomy that is essential for implant treatment planning. Extensive maxillary sinus pneumatization is significantly associated with reduced residual alveolar bone height, while the presence of sinus septa is associated with increased Schneiderian membrane thickness. The high prevalence of radiographically detectable PSAA further highlights the importance of CBCT-based preoperative assessment to facilitate safe sinus floor elevation procedures and reduce the risk of surgical complications.