My retainer has been found! And by the little thief that stole it, no less! He got in trouble for something else this morning and I sent him to his room. A few minutes later he came running out saying "I found your 'tainer!" Apparently he thought this would put him in my good graces. He was right. Not only did he get to come out of his room, but I promptly gave him the candy cane that he'd been begging me for all morning.
So I no longer have to worry about my teeth reverting to their former state of vampire-ly resemblance, and all is right with the world.