Abstract: Disclosed is a base plate assembly for use in mounting a die-stone dental replica, the assembly including a base plate that has a configuration commensurate with at least one dental quadrant, and having a planar upper surface characterized by an array of transverse elongate rectangular sockets. A plurality of mounting blocks are assembled in side-by-side relationship along the plate planar surface, each block having a downward projection adapted to frictionally and releasably hold the block on the base plate, and extending from the tops of the blocks are anchoring tabs designed to be embedded in the wet positive mold of a dental impression and affixed therein when the mold material cures. In a preferred embodiment, the base plate has a modular configuration and is interconnectable with an identical modular unit to form a combined base plate having a configuration commensurate with full bilateral upper or lower dental quadrants.