Nah, my sister had real messed up teeth when she was young, and the dentist referred to it as "shark mouth". It wasn't multiple rows, but several of her teeth had an extra tooth right behind it, leading to her mouth being pretty cluttered until they extracted the extras. Not nearly as extreme as an actual shark, but still a lotta teeth if you were able to see 'em

I had a couple of extras. Most were no big deal, but I had to have one extracted because it was blocking my adult tooth from coming in.