This work introduces a procedure for automatic 3D modeling and discusses its performance in the context of a medical application, namely the 3D modeling of palate's casts. The general interest of the proposed method lays in the fact that a widespread use of 3D modeling in non-engineering applications requires automatic procedures. The specific interest is in the intriguing mixture of open issues concerning 3D modeling, geometrical metrology and medicine represented by the modeling of free-form surfaces of anatomical interest.