A dental model tray (12) for use in forming a dental model has a rigid bottom wall (16) and a relatively thin side wall (17) extending upwardly from the perimeter of the bottom wall (16) to form an open-topped cavity which is adapted to receive the dental casting material. The bottom wall (16) and the side wall (17) are formed integrally of polymeric material, with the side wall (17) being joined to or attached to the bottom wall (16) by a thin membrane-like connector member (19) that is formed integrally with the perimeter of the bottom wall (16) and a lower side edge of the side wall (17). The connector member (19) is frangible and easily broken so that the side wall (17) can be torn away from the base and discarded after dental casting material has hardened in the cavity formed by the side wall (17). The dental model tray (12) further includes an ell-shaped articulator member (13,14) that extends from a back side of the bottom wall (16). A distal end of the articulator member (13,14) is adapted to be pivotally connected to a mutually respective distal end of another articulator member (13,14) of a mutually associated dental tray to form a working dental model.