This vintage garment, which looks like something one might wear after getting a facial injury, supposedly stopped people from mouth-breathing in 1922.
The advertisement says: "You can make sure that you breathe through your nose during the day, but one-third of your time you are asleep." It came in various fabrics for different prices. Cotton for $2, linen for $3 dollars, and if you wanted to be extra fancy, mesh for $4.
I suppose the garment worked by simply forcing the wearer's mouth shut so that they would breathe from their nose instead. I need one of these to wear in public so that when people try to talk to me, they'll quickly see it's not possible for me to open my mouth to respond to them (or perhaps the look of the garment alone will be enough to ward off other humans).
See also: This vintage couture wedding dress looks like a Russian nesting doll, or a tampon
