Abstract: Dental technician's tool and retainer combination adapted for the rapid and accurate positioning of a tooth model die repetitively on a model base support, the tool comprising an axially elongated member having an upwardly extended head portion engageable with the tooth model die, a downwardly tapered bottom portion and a downwardly diminishing intermediate portion of cusped transverse cross-section, the tool retainer comprising an apertured body having an internal wall defining a tapered bore of cusped transverse cross section adapted to cooperatively seat the elongated member against cocking and rotation, the body being adapted to repetitive insertion in and removal from the model base support, and anchor means on the body periphery adapted to block relative movement of the body and the model base support in projecting member seated relation against cocking or rotation of the tooth die in mounted position on the model base support.