People in developing countries need and want to look good just like everybody else. "Developing country" is pretty much the whole world, except Western Europe, North America, Japan, and Australia / NZ.

I'm about 2/3 done with using Invisalign for fixing some pretty severe bite issues. Had I not had anything done, my jaw joint would have continued deteriorating, likely to the point of needing surgery; I was also at higher risk of having teeth break from the added stress (very few of my teeth actually were making proper contact with each other).

The first step of the process was actually removing two of my bottom teeth; the rest of my teeth have then been adjusted to fill the gaps. It's been a long process (almost two years in), and I'm sick of having these stupid plastic things in my mouth all of the time. But it's definitely been more useful than just for cosmetics (though that's a nice side benefit).

I live in a developing country. Most of the dentists here offer Invisalign.

You'd be surprised. I work for a company that manages the technical side of a famiky of brace systems (one of which is a direct competitor to Invision). A lot of activity happening in places I'd least expect.