Do you ever find yourself smiling at inappropriate times? Corpses sure do! They don’t call it a rictus grin for nothing.
But let’s say you’re preparing a body for a wake or funeral or other mortuary occasion. In those cases, you might want to encourage the dearly departed to maintain a more sober expression. Hence this closer for the lips of a corpse:
A plate is inserted into the mouth of the corpse. Those pointy barbs (5) hold the lips in the desired position, “whereby the lips are retained in a proper condition for giving an excellent expression.” USP 2,120,143, p.1, lns 4-6. Personally I’d be a bit squeamish about it, but then, there’s a reason I’m not a mortician.