Purpose: This retrospective study compared the maxillary sinus floor augmentation techniques (lateral and transcrestal approaches) to assess the impact of bone grafting, graft materials, and initial residual bone height (RBH). Materials and Methods: Fifty patients who underwent maxillary sinus floor augmentation for posterior maxillary implant placement were included. Panoramic radiographs were obtained before surgery (T0), immediately after surgery (T1), and 6-10 months post-surgery (T2). Length measurements on panoramic radiographs were performed using a digital caliper at T1 and T2. Statistical validation included one-way ANOVA, t-tests, Mann-Whitney U tests, and correlation analyses. Multivariate linear regression was used to assess associations after adjusting for confounding factors. Results: Of the 50 patients, 35 underwent a transcrestal approach and 15 underwent a lateral approach. The results showed significant endosinus bone gain (ESBG) differences between allogeneic and xenogeneic grafts and no grafts (p < .001). Osteotomy sinus floor elevation without grafting yielded 3.24 ± 1.42 of ESBG. When divided into three groups based on initial RBH, RBH 1 had 27 patients, RBH 2 had 12 patients, and RBH 3 had 11 patients. Within the RBH group 1 (RBH under 4), the lateral ...