Purpose. Development of a special technique for processing data from multispiral computed tomography (MSCT) in patients with orbital injury in order to obtain additional diagnostic information about posttraumatic defects of the inferior orbital wall, as well as the development of defect's classification. Materials and methods. From 2014 to 2018 in Sechenov University 107 patients (100%) with traumatic midface injuries were examined. During hospitalization all patients (n=107; 100%) underwent diagnostic examination within 24-48 hours from admission. Multislice computed tomography was performed using Aquilion One 640 (Canon, Japan) scanner, in a volume mode, with a slice thickness of 0.5 mm, with bone and soft tissue reconstructions. The study was complemented by multiplanar and three-dimensional reconstructions. For the subsequent processing of CT data, the “Vitrea” workstation was used. As part of preoperative planning, in order to optimize treatment tactics and select methods for reconstructing the walls of the orbit, criteria were developed for evaluating and classifying defects of the inferior orbital wall. Results. MSCT revealed damage to the bony structures of the midface in all 107 patients (100%). Fractures of the inferior orbital wall were diagnosed in the majority of patients (n=88; 82%). The type of defect was determined on the basis of the developed classification, taking into account the values of the volumes and areas of inferior orbital wall defects. Small defect of the lower wall of the orbit was determined in 18 patients (17%), medium - in 31 patients (29%), large - in 38 patients (35%), total - in 20 patients (19%). Conclusion. MSCT is the method of choice for examining patients with midface injuries. The developed methodology for assessing defects of inferior orbital wall allows obtaining additional diagnostic information about the state of the inferior orbital wall, classifying defects of the orbital wall and allows personalizing the approach as part of the preoperative planning for each patient with an orbit injury. © 2019 Russian Electronic Journal of Radiology. All rights reserved.