Purpose: The aim of this retrospective clinical case series report was to evaluate the outcomes of patients who underwent zygomatic implant surgery with a recent technical modification of the extrasinus surgical protocol. Materials and Methods: The implant system presented in this study had a novel designed unthreaded body with a 12.5-mm sharp threaded apical end for obtaining maximum retention to the zygomatic bone. A total of 92 patients with severely atrophic maxillae were included in this study. All the patients were treated with a modification of the extrasinus protocol for insertion of 261 zygomatic implants. The mean follow-up of the patients was 34.5 ± 17.1 (SD) months (range: 6 to 72 months). The implant survival rate was the primary outcome. The intraoperative and postoperative complications were evaluated as additional criteria for success. Results: The cumulative implant survival rate was 97.99%. Definitive or provisional prostheses were delivered on the same day of surgery, which resulted in an improvement in the quality of life of the patients. Five implants failed in four patients. No sinusitis or mucositis was seen in any of the patients. Eleven postoperative complications occurred in seven patients. Conclusion: The novel zygomatic surgery protocol introduced in this study can be an effective alternative to augmentation procedures and conventional implants, especially in cases of extremely atrophic posterior maxillae. Keywords: atrophic maxilla, bone atrophy, dental implants, oral rehabilitation, zygomatic implants