Repositioning of the bone window in lateral sinus floor elevation with simultaneous implant placement: A retrospective radiographic study.

Objectives: To retrospectively evaluate whether repositioning the bone window leads to a better outcome of three‐dimensional sinus augmentation in lateral sinus floor elevation (LSFE) with simultaneous implant placement. Methods: 34 patients with a total of 40 implants (14: test group, 26: control group) receiving LSFE with simultaneous implant placement were included in this retrospective research. CBCT images were taken before surgery, immediately and 6 months after surgery. The two‐dimensional augmentation parameters, including apical bone height (ABH), endo‐sinus bone gain (ESBG), and palatal/buccal bone height (PBH/BBH), and three‐dimensional parameters, including augmentation volume (AV) and palatal/buccal augmentation volume (PAV/BAV), were measured. The lateral defect length (LDL) and lateral window length (LWL) were also measured to evaluate the lateral antrostomy recovery. Results: At the 6‐month follow‐up, the reduction rates at ABH, ESBG, and BBH of the test group (ABH: 10.41% ± 30.30%, ESBG: 2.55% ± 8.91%, BBH: 2.50% ± 8.65%) were significantly lower than those of the control group (ABH: 25.10% ± 22.02%, ESBG: 11.47% ± 9.79%, BBH: 7.10% ± 5.37%; p <.05). In addition, the test group showed better three‐dimensional augmentation stability on the buccal side (BAV reduction: 15.51% ± 10.86% vs. 27.15% ± 12.61%; p <.05). Moreover, the LDL/LWL ratio of the test group was significantly lower than that of the control group (p <.05). Conclusion: Within the limitations of this study, repositioning of the bone window in LSFE with simultaneous implant placement could contribute to endo‐sinus augmentation stability on the buccal side at the 6‐month follow‐up. Moreover, it would also facilitate recovery of the lateral antrostomy defect. [ABSTRACT FROM AUTHOR]