Effect of Maxillary Sinus Anatomy on Bone Gain After Lateral Window Sinus Floor Elevation: A Case-Control Study.

Purpose: To evaluate the effect of maxillary sinus anatomy on sinus floor elevation (SFE) operations performed with the lateral window approach. Materials and Methods: CBCT and digital panoramic radiographs were evaluated before and at least 6 months after maxillary sinus floor elevation (SFE) operations performed in 33 maxillary sinus regions in 26 patients. Maxillary sinus volume, grafted volume (GV), sinus width (SW), residual bone height (RBH), and vertical graft resorption (VGR) were calculated. The effects of RBH and SW on GV and VGR were evaluated statistically. Results: The mean GV values in the maxillary sinuses classified as narrow, average, and wide were 2.60 ± 0.57, 3.44 ± 0.65, and 3.70 ± 0.64 cm³, respectively. The mean VGR was 2.12 ± 1.67 mm, and in the sites classified as narrow, average, and wide, the mean VGR values were 1.50 ± 0.79, 1.58 ± 1.28, and 3.46 ± 2.06 mm, respectively. A statistically significant difference in GV and VGR was found between the SW groups. The mean posterior maxillary RBH was 2.30 ± 1.05 mm, and 17 and 16 sinuses were classified as ≤ 2 and > 2 mm, respectively. There was no statistically significant difference in the effect of RBH on GV or VGR. Conclusion: Although posterior maxillary RBH did not affect new bone formation in the sinuses grafted only with hydroxyapatite-derived inorganic bovine bone, with increasing SW, the GV decreased and the VGR increased.