An arch model has a set of teeth and a wall which bridges the set of teeth and has a surface opposite the set of teeth. A sheet containing indicia is placed between the surface of the arch model and a transparent zone of a cover. The cover is separably attached to the arch model. The resulting arch model has the sheet containing indicia disposed between the surface of the arch model and the transparent zone of the cover so that the indicia can be read through the cover. The sheet can be replaced by separating the cover from the arch model, replacing the sheet, and then re-attaching the cover.
