Who decided that “minty fresh” breath was what a clean mouth smells like. I mean there are many other things out there that are just as pleasant like various fruit scents or cinamon etc… Why is mint always associated with a clean mouth?
Okay that two questions; who decided this and why did everyone else agree?
Well, in the past, oral hygeine was almost non-existant. Most people didn’t care if your breath stank because theirs did too. The elites, a bit more sensitive to smells (though not bathing or cleaning their teeth) would douse themselves in perfume and chew leaves, including mint, to cover the stench.
In the recent past, toothpaste manufacturers found that, for some reason, consumers seemed to prefer mint flavor above all others, and so focused on producing mint toothpaste. At first, some tooth-cleaners were not flavored, (some folks even used soap) but others were flavored with cloves, cinnamon, and rose petals. Mint became the most popular, probably because of the “tingly” sensation which implied the teeth were really clean.
Bah! Mint probably covers up the other horrible flavors in toothpaste better than anything else 
Marketing made us like it.