Everyone wants a picture perfect white smile, which is an easily achievable feat with the various advances in orthodontics in the modern world. Even people who are missing a few teeth can achieve a pearly smile with the help of dentures! Unfortunately, the use of acrylic dentures what not always an available option. In the past, the only to achieve realistic dentures without the advent of modern technology was to create the dentures from the teeth of "bone donors."
In the early 19th century, when dentistry was still very primeval and sugar consumption was causing high rates of tooth decay, dentists had to come up with a creative idea to keep up with the demand for dentures. It wasn't enough that they created a new set of teeth for people, those who could afford it wanted denture made out of real teeth because such dentures were easier to use.
Unfortunately, there was only a finite number of living teeth donors, so dentists had to turn to grave robbers to supply them with teeth. The Battle of Waterloo left a plethora of dead bodies to steal teeth from, which was very attractive to grave robbers. After the battle, looters pulled the teeth from dead soldiers left on the battlefield and then sold them to dentists who use them to make dentures. It was a lucrative business, and there was always demand, so they continued to pilfer more teeth from these soldiers, leading to the use of what is now called "Waterloo Teeth."
Luckily for modern humans, technology has advanced enough that we no longer have to put another person's teeth into our mouths to get realistic dentures. But in the past, it was not uncommon for dentures to be made out of the teeth from unconscious donors.