The three-dimensional models of wax belonging to the scientific heritage of the Complutense University of Madrid are a rare and extraordinary material that deserves to be preserved because it has great relevance to understand how surgeons and anatomists found formulas of visual construction that made possible the diffusion of his knowledge about the human body. In the present investigation, an anatomical wax model of the 18th century, with a remarkable degree of structural deterioration and weakness, has been restored, testing a new volumetric loss reconstruction methodology based on photogrammetric digitization of the sculpture, 3D modelling of the lost pieces and 3D printing of their moulds to obtain from them the final copies in waxy material. Due to this methodology, it has been possible to reduce the handling of the figure during the restoration process and the risk of accidental deterioration has been minimized.