Disclosed is a method for pictorially representing and determining tissue densities of a body region, especially in the mouth/jaw/face region (1), of a patient. According to said method, a set of three-dimensional image data representing the body region as well as calibration data that is provided as three-dimensional image data and represents a calibration phantom (5, 8, 15) having a previously known density are photographed by generating an image while the tissue densities are derived from a comparison of the calibration data with the image data. The image data and the calibration data are photographed in the framework of the same shot and in an upright position of the patient, particularly during sitting or standing. The calibration phantom (5, 8, 15) is held in the immediate vicinity of the body region (1) that is to be photographed during the shot by means of a fixture (4, 10, 14) which is fixed independently of the patient's body and in a defined relation to the imaging device.