The influence of maxillary lateral wall thickness on the alveolar horizontal bone dimension after lateral sinus elevation without bone grafts: A retrospective study.

Background and Objective: Lateral wall thickness is an important anatomical entity in sinus lift procedures, but its relationship with crestal bone dimension has received limited attention. This study assessed the association between the thickness of the lateral wall of the maxillary sinus and horizontal crestal bone changes in cases undergoing lateral window sinus lift with simultaneous implant placement and without bone grafts. Methodology: This retrospective study included 35 patients undergoing lateral sinus lift procedures without bone graft and immediate implant placement. Cone-beam computed tomography (CBCT) measurements, including residual bone height (RBH), bone density, and lateral wall thickness, were performed immediate-preoperatively and at six months postoperatively. Change in crestal bone width was compared between patients with lateral wall thickness >1 mm vs. <1 mm. Results: The change in crestal bone width ranged from 0.24 to 4.35 mm at six months. Fourteen cases had lateral wall thickness of >1 mm while 21 cases had <1 mm. The change in crestal bone width was significantly higher at 2.45±0.97 mm in patients with lateral wall thickness <1 mm as compared to 1.54±0.98 mm in patients with lateral wall thickness >1 mm. Pearson's correlation analysis showed statistically significant medium negative relationship between lateral wall thickness and crestal bone width (r=-0.47; p=0.004). A similar relationship was noted with residual ridge height. Conclusion: Lateral wall thickness and RBH may be factors inversely associated with changes in crestal bone width. Incorporating these anatomical determinants into surgical planning may help minimize crestal bone change, and enhance long-term peri-implant stability.