Three-year outcome of a retrospective cohort study on the rehabilitation of completely edentulous atrophic maxillae with immediately loaded extra-maxillary zygomatic implants

Aim: To report retrospectively on the 3-year follow-up results in the rehabilitation of completely edentulous atrophied maxillae using extra-maxillary zygomatic implants. Materials and methods: This retrospective report includes an initial cohort of 39 patients (30 women and 9 men), with a mean age of 53 years, which were followed up for 3 years. The patients were rehabilitated with 39 fixed prostheses and 169 implants (92 zygomatic and 77 regular implants). Final abutments were delivered at surgery stage and a provisional fixed dental prosthesis was manufactured and attached to the implants on the same day as surgery, achieving immediate function. Outcome measures were prosthesis success, implant success, complications, probing pocket depths (PPDs) and marginal bone levels (only for conventional implants). Data were analysed with descriptive and inferential analyses. Results: Five patients dropped out of the study and 1 patient died after 30 months of follow-up due to causes unrelated to the oral rehabilitation. No prosthesis or implant was lost, though 1 implant presented mobility at the 1-year follow-up but remained stable on subsequent follow-ups. Six complications occurred (18%): 5 cases of sinusitis in 5 patients preoperatively diagnosed with sinusitis and whose sinus membrane was disrupted during surgery, and 1 oro-antral communication. Median PPD values were 3 mm in all follow-up appointments (2, 4 and 6 months, 1, 2 and 3 years), comparable to the values of probing depths assessed for standard implants. Conclusions: Within the limitations of this study, the medium-term outcome (3 years) indicates that severely atrophied completely edentulous maxilla rehabilitations supported by immediately loaded zygomatic implants are viable. Keywords: All-on-4, completely edentulous, dental implants, immediate loading, zygoma implants