In the illustrated embodiment, a field generator may be arranged on the body or at an interval therefrom, and produces a defined irregular field. For detecting the field flux a first surface with a plurality of sensor elements is provided, at least a part of which is distributed in two lines running parallel to each other and coupled electrically differentially together. At an interval from the first surface there is provided a second surface, parallel thereto, with further, correspondingly arranged sensor lines. The sensor lines of both surfaces run parallel to one another; the differential signals of the line pair of the first surface are electrically differentially linked to the differential signals of the line pair of the second surface. The device is in particular intended for measuring the location, the attitude and/or the change in location or, respectively, attitude of the jaw or of a tooth of a patient. Thus information may be provided with respect to three degrees of freedom of both translational and rotational movement.