1. An osteoporosis diagnosis support device, comprising: an object region image acquisition unit for acquiring image data of panoramic radiographs including a cortical bone; an outline acquisition unit for acquiring a pixel group A forming an outer edge of the cortical bone in the image data and a pixel group B forming an inner edge of the cortical bone in the image data; a calculation unit for using, as a reference point, a specific point in the image data and is different from the pixel groups A and B to calculate a distance between a specific pixel in the pixel group A and a pixel in a predetermined range in the pixel group B; and an output unit for outputting the distance determined by the calculation unit as a thickness of the cortical bone.