The article says that in early 19th century human teeth were the most popular replacement for teeth, for rich men I guess. Those teeth came mainly from ghouls, which gathered them from the graveyards or battlefields. On the battlefields they took it from the dead soldiers, but also from the wounded. On row of teeth had a price of 20 to 30 guineas at England.

Another source of teeth was the American Civil War, and thousands of them were shipped to England.

Here's a picture:
https://de.wikipedia.org/wiki/Waterl...rmany_crop.jpg