1. A method of producing a dental splint comprising: obtaining a set of 3D surface data, the 3D surface data representing a surface of a patient's oral situation, obtaining a support structure model describing a component configured to fit to a portion of the surface of the patient's oral situation, modifying an apical edge of the support structure model in dependence on the 3D surface data, wherein the apical edge of the support structure model is modified to correspond to a cut-off line generated by a method including: generating a 2D panoramic image of the 3D surface data, forming a coronal edge line representing the highest points along the top of a coronal edge of the 2D panoramic image, and transposing the coronal edge line in an apical direction to form the cut-off line, producing the dental splint in dependence on the modified support structure model.