Quantitative Assessment Of Symmetry In Navigation-assisted Surgical Reduction Of Zygomaticomaxillary Complex Fractures

Objective:To introduce a new method for symmetry evaluation of zygomaticomaxillary complex(ZMC)fracture.ZMC symmetry was assessed preoperative and postoperative with or without surgical navigation respectively.A retrospective study was conducted on epidemiology and treatment of ZMC fracture.Method:The epidemiology,fracture types and treatment methods of patients with ZMC fractures in the Oral and Maxillofacial Surgery Department of the First Affiliated Hospital of Zhejiang University from December 2015 to December 2018 were studied.10 patients were included to conduct quantitative analysis.They were divided into two groups according to the use of surgical navigation.Reduction outcomes were evaluated using three-dimensional computed tomography models.Five pairs of landmarks were identified on all craniofacial models,and asymmetry scores were calculated based on their coordinates.Result:From December 2015 to December 2018,a total of 91 patients(72 males and 19 females;male to-female ratio,3.79:1)were included in this study,which accounting for 28.98%of all maxillofacial fracture patients.Their ages ranged from 17 to 77 years(mean±SD age,40.8±36.2 y).Type B and C by Zingg classification,were the most common type of ZMC fractures and accounted for 71.28%of cases.Traffic accidents(72.4%)was the mean cause of ZMC fractures.Mean treatment delay was 13.65 days.It ranged from 2 to 35 days.10 included patients recovered uneventfully.Greater symmetry was observed in the navigation group than in the control group.Conclusions:The use of surgical navigation can increase postoperative symmetry of the bilateral ZMC.The quantitative evaluation of clinical outcomes is precise and highly reliable.