Objective:To explore the effect of mixed reality (MR) application in the reconstruction of mandibular defects.Methods:Eighteen patients with mandibular defects were enrolled in this study, including 10 male patients and 8 female patients, whose age ranged from 27 to 45 years, and the mean age was 35.4 years. All the patients were from the Stomatological Hospital of the Fourth Military Medical University, during October 2019 to May 2021. Fibular flaps were used for the reconstruction of the mandibular defects. The patients were randomly divided into three groups, six in each group. In group one, MR-guided mandibular defect repair and reconstruction technique was used. In group two, 3D printed guide-assisted mandibular defect repair and reconstruction technique was used, and in the control group, traditional jaw defect repair and reconstruction technique was used. All the procedures were performed by the same team. Cone beam computed tomography (CBCT) was used for analysis of surgical accuracy, and questionnaires were used to evaluate the outcome of medical communication, occlusal relationship, appearance restoration, and medical experience satisfaction.Results:The mean surgical errors in the group one and group two were (1.75±0.44) mm and (1.81±0.16) mm respectively, which were both significantly lower than that in the control group (3.05±0.83) mm ( tMR=3.38, t3D=3.56, P<0.01). The medical communication (4.60±0.35, 4.52±0.28, tMR=2.90, t3D=2.77, P<0.05), occlusal relationship (4.17±0.32, 4.28±0.39, tMR=3.07, t3D=3.29, P<0.05), and medical experience satisfaction scores (4.26±0.45, 4.25±0.67, tMR=2.50, t3D=2.26, P<0.05) in the experimental groups were significantly higher than those in the control group (4.02±0.34, 3.58±0.33, 3.56±0.32, respectively). There was no significant difference in the satisfaction of appearance recovery among all the groups ( P>0.05). Conclusions:MR-guided mandibular repair and reconstruction surgery has high accuracy and is also beneficial to the recovery of occlusal relationship and medical communication.