ABSTRACT
Objective: To evalute the accuracy and clinical outcome of a real-time navigation system for the placement of quad zygomatic implants. Methods: Twenty-four patients [9 males and 15 females, mean age was (50.8±14.7) years old], from January 2015 to December 2019, with 96 zygomatic implants placed under a real-time navigation system in Department of Second Dental Center and Department of Oral Implantology of Ninth People's Hospital, Shanghai Jiaotong University School of Medicine were included in the study. The preoperative and the postoperative multislice CT or cone-beam CT were fused to measure and record the entry, exit and angle deviation between the planned and placed implants. The implants were divided into groups according to implant insertion approach (real-time navigation and free-hand), implant length (<47.5 mm and ≥47.5 mm) and implant position (proximal and distal implant). And the differences of implant accuracy were analyzed. The intraoperative and postoperative complications were also recorded. The implant survival rate was evaluated after 6 months follow-up. A P value<0.05 indicates statistical significance. Results: The mean entry, exit and angle deviation of zygomatic implants were (1.49±0.64) mm, [2.03(1.58, 2.40)] mm and (2.49°±1.12°), respectively. The average entry, exit and angle deviation of the navigation guided implant insertion group were (1.45±0.60) mm, (1.96±0.44) mm and (2.66±1.13°) respectively, while those of the free-hand group were (1.50±0.64) mm, (2.04±0.79) mm and (2.50°±1.13°) respectively. There was no significant difference between the two groups (P>0.05). The average entry, exit and angle deviation of the group with length<47.5 mm were (1.42±0.60) mm, (2.13±0.60) mm and (2.61°±1.08°) respectively and those of the group with length ≥ 47.5 mm were (1.52±0.65) mm, (1.98±0.82) mm and (2.43°±1.14°) respectively. No significant difference was found between the two groups (P>0.05). In proximal implant group, the average entry, exit and angle deviation were (1.55±0.69) mm, (2.05±0.92) mm and (2.48°±1.16 °) respectively while those of distal implant group were (1.43±0.57) mm, (2.01±0.57) mm and (2.49°±1.10°), respectively. No significant difference was detected between the two groups (P>0.05). All zygomatic implants were placed uneventfully. There were no intra-operative complications, and post-operative reversible complications developed in 3 patients. Two zygomatic implants were lost and the overall zygomatic implant survival rate was 97.9% (94/96) within a follow-up of 6 months. Conclusions: Quad zygomatic implant placement can be achieved with high accuracy and predictable clinical outcome under guidance of a real-time navigation system.
