This item came to me from my good friend and makeup artist, Mitch Boudrot. According to him, these teeth were slush cast by John Chambers and used in the masks and prosthetics of the ape characters in the PLANET OF THE APES films. There are numbers or letters on them so I assume they were designed for specific masks or prosthetics and these numbers or letters identified which one (or which actor perhaps) they should go to. They were cast in quantity and used each time they were required to have teeth in the apes' mouths. That's called planning and thinking ahead. Yeah, John!!