If I were to suggest that you could whiten your teeth by gargling with your first-of-the-morning urine, and you decided to try it and it made you ill, you probably could not sue me successfully.
By the way, for those who enjoy some of the strange law stories found on the best legal blogs, you might like the anthology "No Law Against Love" by Deborah MacGillivray, Jacqui Rogers et alia.
Which has very little to do with teeth.... or the dubious effectiveness of urine as a beauty regimen, but here are a couple of interesting links:
Dr. Charles Gemmi of Philadelphia gives us eight shocking facts about teeth:
For something more visually inspiring, Google "weird teeth". Speaking for myself, others may be more thorough, and with the exception of vampire romances, I've not noticed a lot of interest in alien dentition in fiction. Like visits to the bathroom once the seat is down, the contents of a hero's mouth are just not that romantic.
As a matter of survival, primates have always had to read facial-grimace language for welcomes, warnings and other cues about how to stay safe. There is a PEAK game where you have milliseconds to identify friendly faces out of a mass of questionable tooth exposure, and also closed-lip smiles. I am exceptionally good at it.