Lol, yes i know both...
The first one means someone had gaps in their teeth or missing teeth. "His teeth were so messed up, he could eat corn through a picket fence."
The second means doing really well, when cotton gets tall it produces more cotton, so more money. A lot of people say sitting in high cotton, meaning making a lot of money from a business.
Hey you spelled learned wrong..... in the south it is learn't......