Comparative evaluation of infrasinus residual ridge height in cone-beam computed tomography and on-site measurements during indirect sinus lift osteotomy: An observational study.

AIM: To compare infra-sinus residual ridge height measured preoperatively using Cone-Beam Computed Tomography (CBCT) with intraoperative measurements recorded during indirect sinus lift osteotomy using the Crestal Approach Sinus (CAS) kit, and to evaluate the reliability of CBCT in posterior maxillary implant planning.

SETTINGS AND

DESIGN

This prospective observational clinical study was conducted on participants requiring implant rehabilitation in the posterior maxilla.

MATERIALS AND

METHODS

Fifty participants indicated for implant placement in the posterior maxilla were included. Infra-sinus residual ridge height was measured preoperatively on CBCT scans using Planmeca Romexis® software. Intraoperative measurements were recorded during indirect sinus lift osteotomy using a depth gauge from the CAS kit. Preoperative CBCT measurements were compared with intraoperative findings.

STATISTICAL ANALYSIS USED: Statistical analysis was performed using Jamovi version 2.3.28 software. The Shapiro-Wilk test was applied to assess the normality of numerical variables. As the data were non-normally distributed, the Wilcoxon signed-rank test was used to determine the significance of differences between CBCT and intraoperative measurements. A p-value <0.05 was considered statistically significant.

RESULTS

The mean infra-sinus residual ridge height measured on CBCT was 4.66 ± 0.798 mm, while the mean intraoperative measurement was 6.50 ± 1.074 mm. The difference between the two measurement methods was statistically significant (p < 0.001), indicating a consistent underestimation of ridge height by CBCT.

CONCLUSION

CBCT consistently underestimates infra-sinus residual ridge height by approximately 1.86 mm when compared with intraoperative measurements. Although CBCT remains indispensable for pre-surgical planning, reliance on CBCT alone may be insufficient for sinus lift procedures, particularly in borderline cases. A dual-modality approach combining CBCT evaluation with intraoperative verification improves accuracy and safety, thereby supporting evidence-based and precise clinical decision-making.