Purpose: To evaluate the effectiveness and predictability of a novel biomechanical, minimally invasive bone instrumentation technique that enhances bone density through compaction grafting, called osseous densification, and allows for transcrestal sinus membrane elevation and augmentation with simultaneous implant placement. Materials and Methods: Patients who were consecutively treated with the bone densification and transcrestal sinus augmentation technique and were followed up in three treatment centers between May 2012 and September 2017 were included in this retrospective study. The summary statistics are presented as means for continuous variables and percentages for categorical variables. Results: In total, 222 patients with 261 implants were included in the final clinical analysis. The included follow-up period ranged from 6 to 64 months with a mean of 35 months. The subsinus residual bone height at baseline was 5.4 mm (SD: 1.9). Following the sinus augmentation, a significant vertical increase of 7 mm (SD: 2.49) was observed. No sinus membrane perforations and no late implant failures were observed from 6 up to 64 months follow-up, yielding a cumulative implant survival rate of 97%. Conclusion: This osseous densification technique for maxillary implant site preparation with transcrestal sinus augmentation and simultaneous implant placement led to favorable clinical outcomes with up to 64 months of follow-up. Keywords: atrophic maxilla, bone substitutes, compaction autografting, densifying burs, maxillary sinus, osseous densification, sinus augmentation, sinus elevation procedure