A Retrospective Cohort Study of the Survival Rate of 88 Zygomatic Implants Placed Over an 18-year Period

Purpose: The management of patients with a severely atrophic or resected maxilla with zygomatic implants can be surgically challenging, but postoperative complications are relatively uncommon. This retrospective cohort study evaluated the percentage survival rates of zygomatic implants placed over an 18-year period. Materials and Methods: This study evaluated patients receiving zygomatic implants in primary-care (specialist referral dental practice) and secondary-care (hospital) settings over an 18-year period. Results: In total, 88 zygomatic implants were placed in 45 patients aged between 42 and 88 years. Of the 88 implants, 54 were immediately loaded. The implant survival rate was 94.32%, with five implants failing during the study period (implant-level cumulative failure rate: 5.68%; mean follow-up: 7.5 years; maximum: 18 years). The failures were not significantly associated with sex, surface finish, implant length, zygomatic anatomy-guided approach (ZAGA) classification, or implant position (all P values > .05). All failed implants were fitted with fixed prostheses. Failures occurred between 6 months and 15 years after placement. Conclusion: This study of zygomatic implants placed in patients with a severely atrophic and resected maxilla confirms that this approach is a predictable method for supporting fixed or removable prostheses up to 18 years, demonstrating high survival rates. Given the low number of failures, no potential risk factors for failure could be identified. Keywords: implant-supported denture, maxilla, survival, zygomatic implant