Abstract: A method for determining the alteration of the shape of a three-dimensional object from at least one two-dimensional image of the object, wherein the original three-dimensional model shape of the object is known—or is ascertained from the at least one two-dimensional image of the object. The three-dimensional model shape is rotated such that at least one two-dimensional projection of the three-dimensional model shape matches or resembles at least one partial area or contour of the at least one two-dimensional image of the object, and the area or areas are ascertained in which the at least one two-dimensional image of the object deviates from the two-dimensional projection(s) of the three-dimensional model shape, wherein the deviating two-dimensional area or areas are identified as deformed areas and, after the deformed area or areas have been back-projected onto the three-dimensional model shape, the three-dimensional deformation of the three-dimensional object is ascertained.