Zygomatic Implants for the Rehabilitation of Atrophic Maxillae: A Retrospective Study on Survival Rate and Biologic Complications of 206 Implants with a Minimum Follow-up of 1 Year

Purpose: To carry out a retrospective analysis of the placement of zygomatic implants in atrophic maxillae and to assess the outcomes in terms of survival rate and biologic complication incidence, with a follow-up of at least 1 year and in 13% of cases, longer than 5 years. Materials and Methods: The study included all patients rehabilitated through zygomatic implant surgery from 2006 to 2017 and excluded those treated in 2018 to guarantee a minimum follow-up of 1 year. Depending on the specific case, one, two, or three zygomatic implants were placed in combination with conventional implants, or four zygomatic implants were placed alone (zygoma quad). All implants were placed by the same surgeon in a private clinic through an anatomy-guided surgical approach and were immediately loaded with screwed provisional prostheses up to the end of the osseointegration phase. Patients who did not undergo any or the last follow-up visits were not included in order to assess the real conditions of implants, soft tissues, and maxillary sinuses in the last year of follow-up (2018). Results: A total of 206 zygomatic implants were placed in 102 patients. There were only two failures due to a lack of osseointegration (0.97%): in one case, 3 months after placement and in the other one, 2 years after placement. There were five cases of sinusitis (2.42%), two of which also presented oroantral communication (0.97%); in three cases, antibiotic and conservative treatments alone were not effective, so the removal of the zygomatic implant was necessary. Finally, two cases of mucosal recession (0.97%) appeared in two anterior zygomatic implants. The global survival rate was 97.57%, and all biologic complications are currently stable. Conclusion: In this study, the rehabilitation of atrophic maxillae through zygomatic implants was shown to be a predictable treatment, which allows a graftless approach and makes it possible to carry out immediate loading protocols, with enormous psychologic advantages for patients. Survival rates are high, and complication incidence is low. Thus, at present, zygomatic implants may be considered a reliable treatment option in the case of severe atrophic maxillae.