Radiographic changes in the maxillary sinus following closed sinus augmentation

Background: The primary objective of this study is to evaluate the accuracy of 3-dimensional (3D) imaging in detecting radiographic and morphological graft changes compared to traditional 2-dimensional (2D) imaging. Additionally, the study aims to assess the distribution of graft material and the extent of resorption occurring between baseline and 6 months post-implant placement following transcrestal sinus augmentation. Methods: This study employed a transcrestal approach utilizing an osseodensification protocol for sinus augmentation with mineralized freeze-dried bone allograft. Immediately post-operatively, a standardized periapical radiograph (PA) was taken using a standardized paralleling device with bite registration material. Furthermore, a low-volume cone beam computed tomography (CBCT) radiograph was obtained. Following a 6-month healing period, both radiographs were repeated for analysis and comparison to baseline parameters. Results: A total of 22 subjects completed the study. At 6 months post-surgery, PA evaluations indicated a reduction in apical graft height (AGH) of 55.9%, endo-sinus bone gain (ESBG) reduction of 29.6%, and elevated membrane apex (EMA) reduction of 8.4%. CBCT analysis showed slightly higher reductions, with AGH, ESBG, and EMA reductions of 60.4%, 32.6%, and 12.2%, respectively. A paired t-test comparing the accuracy of the 2D and 3D models' ability to detect changes in graft material resulted in a p-value of 0.2168. Conclusions: Periapical imaging is relatively accurate when standardized, whereas CBCT provides a more precise representation of the graft material distribution and reduction. Significant reductions in AGH, ESBG, and EMA were observed at 6 months, with PAs indicating less change in bone augmentation compared to CBCT. ClinicalTrials.gov Identifier: NCT06296459. Plain language summary: The removal of posterior teeth results in expansion of the maxillary sinus, which can limit the bony support for dental implants. To overcome this, the maxillary sinus can be augmented through various techniques and with various materials. This study evaluated augmenting the sinus with a transcrestal approach utilizing a freeze-dried bone allograft. At 6 months postoperatively, x-ray evaluation demonstrated a reduction in graft height and endo-sinus bone gain. Comparison of imaging techniques revealed statistical accuracy of both 2D and 3D models to detect changes in the graft material.