See my other comment itt for the source.
The animal data that convinced regulators and researchers to proceed to human trials represents years of painstaking experimental work.
In the mouse studies published in scientific journals since 2018, blocking USAG-1 consistently produced supernumerary teeth in animals that should have grown only their standard set.
The ferret studies were particularly significant, because ferrets, like humans, are diphyodont, meaning they naturally develop only two sets of teeth in a lifetime.
When ferrets were treated with the USAG-1 blocking antibody, they grew additional teeth beyond their natural adult set.
The teeth were complete.
They were functional.
They bonded with the surrounding bone and tissue in the same way naturally occurring teeth do.