This study aims to quantitatively evaluate the effects of bisphosphonate use duration and route of administration on mandibular cortical and trabecular bone in postmenopausal women. Ninety postmenopausal women over the age of 50 were included in this study. Trabecular bone density was specified numerically by fractal dimension (FD) in the region of interest selected on the panoramic radiograph. The width of the mandibular cortical (MCW) bone under the mental foramen of the mandible was measured. Mann-Whitney U test was used for parameters that did not show a normal distribution. Spearman rho correlation test was used to determine the relationship between continuous measurement parameters. It was observed that FD and MCW of dentate and edentate individuals using bisphosphonate were statistically significantly lower than those of healthy individuals (P < .05). There was no significant correlation was found between the duration of use of bisphosphonates and the fractal values obtained from the relevant regions of the mandible (P > .05). Fractal dimension was found to be lower in oral bisphosphonate use than in intravenous bisphosphonate use. The width of the mandibular cortical bone values was found to be lower in individuals using bisphosphonate than in healthy individuals. Fractal dimension and MCW may benefit clinicians as quantitative parameters in panoramic radiography in the diagnosis of osteoporosis.