Abstract: A mold for taking impressions of upper and lower jaws has a main part including a U-shaped generally flat base plate having a rearwardly concave and open U-shaped inner periphery and a forwardly convex U-shaped outer periphery, a U-shaped rim projecting transversely of the plate from the outer periphery thereof, and a handle projecting forward from the outer periphery and formed with a rearwardly open passage. This main part can be used with either an upper-jaw or lower-jaw insert. The upper-jaw insert has a U-shaped upper-jaw wall generally complementarily fittable in an engaged position with the inner periphery of the base plate to form therewith a transversely open U-shaped recess adapted to receive molding compound, a palate plate bridging the U-shaped upper-jaw wall, and a stem projecting forward from the upper-jaw wall and engageable in the passage when the upper-jaw wall and rim define the recess.