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Quad Zygomatic Implants: A Systematic Review and Meta-analysis on Survival and Complications.

PURPOSE
To assess the postoperative complications and outcome (implant survival) of quad zygomatic implants inserted in patients with edentulism and severely atrophic maxillae.


MATERIALS AND METHODS
Two independent reviewers conducted an electronic search of the literature (PubMed, Scopus, EBSCO, Web of Science) from January 2000 to February 2019. The inclusion criteria were articles published in English reporting data of at least five patients with severely atrophic edentulous maxillae undergoing placement of four zygomatic implants without additional insertion of standard implants, with a minimum of 6 months of follow-up. Data extracted included number of patients, characteristics of the maxillary defect, number of zygomatic implants, implant details, surgical procedure, prosthetic rehabilitation, postoperative complications, survival rate, and length of follow-up after definitive prosthesis delivery.


RESULTS
Eleven studies with 166 patients were included. The heterogeneity among studies was not significant. The pooled incidence rates of complications were as follows: sinusitis 12% (95% confidence interval [CI]: 4% to 23%), malposition and surgical guiding failure 11% (95% CI: 3% to 21%), local infection/injury 10% (95% CI: 3% to 18%), and prosthetic complications 5% (95% CI: 0% to 13%). The implant survival rate ranged between 95.8% and 100%, and the pooled implant survival rate in the meta-analysis was 98% (95% CI: 97% to 99%).


CONCLUSION
Quad zygomatic implants inserted in patients with severely atrophic edentulous maxillae have a high implant survival rate, but the incidence of complications should not be underestimated.