OBJECTIVE : To provide reference data for reconstruction of bilateral midfacial defects for which "mirror technique" cannot be applied. METHODS : The present study included 4 patients (3 males and 1 female) with post-traumatic bilateral midfacial fractures and defects. The most similar model was retrieved from a database of 552 normal Chinese people and used to guide preoperative virtual surgery planning. All patients underwent open reduction, internal fixation, and reconstruction surgery in 1 stage. A custom-made titanium prosthesis was used to repair the defects of frontal and naso-orbital-ethmoid (NOE) region in 1 patient. Two fibular flaps were used to repair the maxillary defects. A deep circumflex iliac artery flap was used to reconstruct large midfacial defects involving the right zygoma. A surgical navigation system was applied in 3 patients. RESULTS : The 4 patients were followed for 6 to 42 months. Two patients had finished all therapies and had satisfactory functional and cosmetic results. The appearance of 1 patient was obviously improved; that patient was still receiving treatment for denture prostheses. One patient had undergone first-stage reconstructive surgery and had normal occlusion at 6 months of follow-up. For 3 patients whose treatment had been assisted by navigation, the average surgical deviation was less than 3 mm (range, 1.5 to 2.2). For the patient whose treatment had not been assisted with navigation, the deviations differed in different areas: 3.47 mm in the right zygomaticomaxillary complex, 5.48 mm in the NOE area, and 5.91 mm in the maxillary area. CONCLUSIONS : For patients with bilateral post-traumatic midfacial defects across the midline, the use of a 3-dimensional craniomaxillofacial database can be considered a feasible method for providing reference data for preoperative planning.