Three-dimensional Volumetric Evaluation of Deproteinized Bovine Bone Mineral Graft Dimensional Changes After Lateral Window Sinus Floor Elevation: a Long-term Retrospective Study up to 12 Years.

This study aims to assess graft volume changes and stability up to 12 years after lateral sinus floor elevation using natural bovine bone. The research will involve patients who underwent external sinus lifts starting 2011 and had pre-operative and post-operative CBCT scans. The study will include a retrospective comparison of graft volume changes using three time points: T0 (pre-operative CBCT, showing residual bone height), T1 (post-operative CBCT acquired at different time points, including immediately after the procedure T' and 9-months post-operative scans T''), and T2 (long-term post-operative CBCT). The residual bone height from T0 will be excluded in subsequent scans to focus on evaluating changes in graft volume.

For the primary outcome evaluate radiographically in 3D using CBCT volumetric changes in region of lateral sinus lift using deproteinized bovine bone graft material.

For the secondary outcome is to evaluate potential differences in graft volumetric changes among different age groups, genders, smoking vs. non-smoking patients and to evaluate implant survival. In addition to that, to detect a potential pattern in graft resorption/ stabilization for only 11 patients from Ghosn et al's study (with immediate post-operative CBCT and 9 months post-operative CBCT).

For this, a minimum sample size of 52 patients (increasing the sample size as much as possible > 60 for more accurate results) are needed for statistical analysis to detect a significant difference in graft volume and an additional 11 patients are needed from Ghosn's et al study for an additional analysis (exploratory purpose).

Patient's inclusion criteria include: