Abstract: PURPOSE: To explore the validity of 3D printing technique in the treatment of unilateral comminuted zygomatic bone fracture. METHODS: Twenty-one patients with unilateral comminuted zygomatic bone fracture were included in the present study, which were treated from hospital January 2014 to April 2017. All patients underwent CT scan and the data were imported in Mimics 10.01 software. The zygomatic bone of healthy side was mirrored to the fracture side to rebuild a "perfect" reduction model. Bone fixation plates were pre-modeled on the model printed by a 3D printing machine and used for bone reduction and fixation during operation. Three dimensional measurements were performed to evaluate the validity of 3D printing based on pre- and post-operative three dimensional CT model. SPSS25.0 software package was used to perform paired t test on the measured data. RESULTS: No significant difference were observed between postoperative CT model and preoperative "perfect" reduction model. All patients were satisfied with their facial appearance. CONCLUSIONS: 3D printing technique is helpful to improve the accuracy of reduction of unilateral comminuted zygomatic bone fracture via preoperative pre-modeling.

Key words: 3D printing, Comminuted zygomatic bone fracture, Pre-fabrication