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Purpose: To compare the clinical outcome of immediately loaded cross-arch maxillary prostheses supported by zygomatic implants vs conventional implants placed in augmented bone., Materials and Methods: In total, 71 edentulous patients with severely atrophic maxillas without sufficient bone volumes for placing dental implants, or when it was possible to place only two implants in the anterior area (minimal diameter 3.5 mm and length of 8 mm) and less than 4 mm of bone height subantrally, were randomised according to a parallel group design to receive zygomatic implants (35 patients) to be loaded immediately vs grafting with a xenograft, followed after 6 months of graft consolidation by placement of six to eight conventional dental implants submerged for 4 months (36 patients). For immediate loading, zygomatic implants had to be inserted with an insertion torque superior to 40 Ncm. Screw-retained metal reinforced acrylic provisional prostheses were provided, to be replaced by definitive Procera Implant Bridge Titanium prostheses (Nobel Biocare, Göteborg, Sweden), with ceramic or acrylic veneer materials 4 months after initial loading. Outcome measures were: prosthesis, implant and augmentation failures, any complications, quality of life (OHIP-14), patients' number of days with total or partial impaired activity, time to function and number of dental visits, assessed by independent assessors. Patients were followed up to 1 year after loading., Results: No augmentation procedure failed. Five patients dropped out from the augmentation group. Six prostheses could not be delivered or failed in the augmentation group vs one prosthesis in the zygomatic group, the difference being statistically significant (difference in proportions = -16.5%; P = 0.045; 95% CI: -0.34 to -0.01). Eight patients lost 35 implants in the augmentation group vs two patients who lost four zygomatic implants, the difference being statistically significant (difference in proportions = -20.1%; P = 0.037; 95% CI: -0.38 to -0.02). A total of 14 augmented patients were affected by 22 complications, vs 28 zygomatic patients (40 complications), the difference being statistically significant (difference in proportions = 34.8%; P = 0.005; 95% CI: 0.12 to 0.54). The 1-year OHIP-14 score was 3.93 ± 5.86 for augmented patients and 3.97 ± 4.32 for zygomatic patients with no statistically significant differences between groups (mean difference = 0.04; 95% CI: -2.56 to 2.65; P = 0.747). Both groups had significantly improved OHIP-14 scores from before rehabilitation (P < 0.001 for both augmented and zygomatic patients). On average, the number of days of total infirmity was 7.42 ± 3.17 for the augmented group and 7.17 ± 1.96 for the zygomatic group, the difference not being statistically significant (mean difference = -0.25; 95% CI: -1.52 to 1.02; P = 0.692). The number of days of partial infirmity were on average 14.24 ± 4.64 for the augmented group and 12.17 ± 3.82 for the zygomatic group, the difference being statistically significant (mean difference = -2.07; 95% CI: -4.12 to -0.02; P = 0.048). The mean number of days that needed to have a functional prosthesis was 444.32 ± 207.86 for augmented patients and 1.34 ± 2.27 for zygomatic patients, the difference being statistically significant (mean difference = -442.98; 95% CI: -513.10 to -372.86; P < 0.001). The average number of dental visits was 19.72 ± 12.22 for augmented patients and 15.12 ± 5.76 for zygomatic patients, the difference not being statistically significant (mean difference = -4.61; 95% CI: -9.31 to 0.92; P = 0.055)., Conclusions: Preliminary 1-year post-loading data suggest that immediately loaded zygomatic implants were associated with statistically significantly fewer prosthetic failures (one vs six patients), implant failures (two vs eight patients) and time needed to functional loading (1.3 days vs 444.3 days) when compared to augmentation procedures and conventionally loaded dental implants. Even if more complications were reported for zygomatic implants, they proved to be a better rehabilitation modality for severely atrophic maxillae. Long-term data are absolutely needed to confirm or dispute these preliminary results., Competing Interests: This study was originally supported by Nobel Biocare (Göteborg, Sweden), the manufacturer of the implants, and of the provisional and definitive prosthetic components used in this study, which were provided free to the patients; however, before any results were known, Nobel Biocare withdrew the financial support and recruitment had to be stopped. Tecnoss (Giaveno, Italy) kindly donated the bone substitutes and the membranes, whereas Global D (Brignais, France) donated the osteosynthesis screws. Data property belonged to the authors and the manufacturers in no means interfered with the publication of the results.

Purpose: To evaluate the clinical outcome of maxillary prostheses supported by four immediately loaded zygomatic implants in the rehabilitation of edentulous patients with severe atrophic maxillae after 5 years of function., Materials and Methods: Out of a total of 17 consecutive patients with severe atrophy in the maxillae (Cawood and Howell classification C-VI and D-V or D-VI) and whom were rehabilitated using four immediately loaded zygomatic implants, three were lost during follow-up. Outcome measures were success rates of the prostheses, success rates of the zygomatic implants, complications and oral health-related quality of life (OHIP-14 questionnaire)., Results: In 14 patients assessed at 5 years after operation, no prosthesis or zygomatic implants failed, although one implant placed in an unfavourable position was not used. Fifty percent of the patients had complications, which included penetration of the orbital cavity during the drilling procedure (1 patient), infection followed by a fistula at one zygomatic implant (1 patient), sinusitis (2 patients), fracture of the abutment screw (1 patient) and fracture of the prostheses (2 patients). All complications were resolved without clinical consequences. At 5 years the mean score of the OHIP-14 was 3.8, which is similar to that of the general population., Conclusion: Results at 5 years indicate that the use of four immediately loaded zygomatic implants is a reliable approach for successful rehabilitation of edentulous patients with severely atrophied maxillae.

Purpose: To assess the clinical 3-year outcome of prostheses supported by four immediately loaded zygomatic implants., Materials and Methods: A total of 17 consecutively treated patients (7 men, 10 women, mean age 57.7 years) with severe maxillary atrophy were immediately rehabilitated with prostheses supported by four immediately loaded zygomatic implants. The patients were followed up for 3 years and the outcome measures included success rates of the prostheses, success rates of the zygomatic implants, complications and oral-health related quality of life (OHRQoL)., Results: No patients dropped out. No prosthesis or zygomatic implants failed, though one implant was not used to support the final prosthesis because it emerged in an unfavourable position. Seven complications occurred: penetration of the orbital cavity during the drilling procedure with no relevant consequences; an infection followed by a fistula at one zygomatic implant, which was resolved with antibiotic treatment and surgical drainage; two patients developed sinusitis, and were successfully treated with antibiotics and meatotomy; fracture of the abutment screw occurred in one patient; and fracture of the prosthesis occurred in two patients and the definitive prostheses were repaired. The average score for the OHIP-14 questionnaire was 2.7, which was similar to that of the general population., Conclusions: The present 3-year study suggests that prostheses supported by four immediately loaded zygomatic implants can be used for successful rehabilitation of patients with severely atrophic maxillae.

Purpose: This prospective study was designed to assess the long-term outcome of immediately loaded zygomatic implants placed in atrophic maxillae., Materials and Methods: Forty-two consecutively treated patients received 81 zygomatic implants and 140 conventional implants for oral rehabilitation and were followed for 5 years. Complete arch rehabilitation was accomplished in 37 patients and partial arch rehabilitation in 5 (one zygomatic implant in combination with two conventional implants). Outcome measures were prosthetic and implant failures, and complications., Results: Twelve zygomatic and 22 conventional implants in 6 patients were not reviewed as patients were lost to follow-up. One zygomatic implant was removed at the 3-year follow-up visit because of lack of osseointegration and disturbances around the zygomatic region. The success rate of zygomatic implants was 98.5% (68/69). Six conventional implants were lost, with a success rate of 94.9% (112/118). One of the definitive prostheses was changed after 4 years of follow-up. Six complications occurred during the entire follow-up period., Conclusions: The 5-year prognosis was found to be good for immediately loaded zygomatic implants together with conventional implants in severely resorbed maxillae.