© 2021, The Author(s), under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd.Objectives: The aim of this study is to evaluate the mandibular trabecular and cortical bone structure of patients using systemic glucocorticoid (GC) and compare to control group with the fractal analysis (FA) and radiomorphometric indices. Methods: Two researchers retrospectively investigated 192 dental panoramic radiographs to compare individuals using systemic GCs to healthy controls. FA was performed in 4 different regions; geometrical center of the mandibular ramus (ROI1), cancellous bone on supracortical mandibular angle area inferior to the mandibular canal (ROI2), cancellous bone on mesial to the mental foramen (ROI3), basal cortical bone extending mental foramen to the first molars’ distal root in the mandibular corpus (ROI4). Panoramic mandibular index (PMI), mandibular cortical width (MCW) and mandibular cortical index (MCI) were performed for evaluate cortical thickness and porosity. The Shapiro–Wilk test was used to determine the normal distribution of the data, the independent t test for comparison of values and the chi-square test for descriptive statistics. Results: There were statistically significant differences in ROI4 and MCW. The fractal dimension (FD) values in ROI4 and MCW were significantly lower in study group. There were no significant differences in FD values in ROI1, ROI2, ROI3 and PMI and MCI measurements between both groups. Conclusions: FA and radiomorphometric measurements is an efficient method to detect early changes in bone mass. In our study, ROI4 and MCW were significantly lower in study group. Osteoporosis prevention should be considered in patients using systemic GCs.