Zygomatic implants placed with a two-stage procedure: a 5-year retrospective study

Abstract

Aim: The zygomatic implant represents a non-grafting alternative for the oral rehabilitation of patients with extreme resorption of the maxilla. Nevertheless, there are few studies concerning their long-term prognosis. The purpose of this retrospective study was to evaluate the prosthetic rehabilitation success rate and the survival rates of machined surface zygomatic implants and conventional implants placed using a 2-stage protocol in 21 consecutively treated patients with atrophic maxillae after a 5-year followup period.

Materials and methods: A total of 24 consecutively treated patients (8 men, 16 women), with a mean age of 51.4 years (range 36 to 72 years) were included in this study. Rehabilitations were accomplished in 22 edentulous arches, and two partially edentulous arches. In total, 45 zygomatic and 109 conventional implants were inserted. A total of 21 patients had a screw-retained fixed implant-supported prosthesis within 6 months of implant placement and three patients had an implant-supported overdenture. Outcome measures were survival rates of the prosthetic rehabilitations, of the zygomatic and conventional implants, as well as complications.

Results: Three patients dropped out, two after 1 year and one after 3 years. Continuous stability of the prostheses was achieved in 20 out of the 21 patients throughout the study. Therefore, the success rate for the prosthetic rehabilitation after 5 years was 95.8%. One overdenture supported on two zygomatic implants was removed after 1 year of function. The patient is currently waiting for the installation of two more zygomatic implants or a grafting procedure. One zygomatic implant was lost giving a survival rate 97.4% after the 5-year follow-up period. A total of 11 conventional implants were lost, resulting in a survival rate of 89.9% after 5 years of follow-up. Sinusitis was observed in five patients throughout the study, which was solved with antibiotics, meatotomy, or Caldwell-Luc antrostomy with no further consequences.

Conclusions: Zygomatic implants together with conventional implants in the atrophic maxillae appear to have an acceptable 5-year clinical outcome.