Extra-sinus Zygomatic Implants to avoid Chronic Sinusitis and Prosthetic Arch Malposition- 12-years of experience.

To report retrospectively on the 12-years follow-up results of the treatment and rehabilitation of edentulous maxillae, applying extra-sinus zygomatic implants alone or in combination with intra-sinus zygomatic implants. We recruited 22 Patients with 35 zygomatic Brånemark System Implants; 24 implants in the standard Brånemark protocol through the sinus and 11 extra - sinus implants outside the sinus. Additionally, 147 regular implants were placed (Brånemark System, Straumann, Nobel Replace, SternGold). The minimum follow-up period was from 50 months to a maximum of 152 months. The Zygoma survival rate after 12 years was 97.15%. Chronic sinusitis occurred in 11.42% of patients. We lost 1 (2.85%) zygomatic implant placed through the sinus and none of those in the extra - sinus position. The survival rate of the regular implants was 93.87%. Chronic sinusitis occurred in 4 patients (11.42%) who received Zygomatic implants using the standard protocol through the sinus. None of the extra - sinus zygoma patients developed sinusitis. Peri - implantitis was detected with only three zygomatic implants. In the original P-I Brånemark zygoma protocol (Brånemark System, Sweden) the implants were passing through the sinus which resulted in chronic sinusitis in some patients and malposition of the prosthetic platform towards the palate. These complications can be avoided by the extra - sinus placement of zygoma implants as demonstrated in this study.