I'm 19 and my teeth are done falling out and have been for a long time. My upper lateral incisors never grew in on either side they just didn't exist. That caused a lot of my teeth to kind of space out including my front. The enamel on my teeth has always been weak and it's caused some of my back teeth to be brittle around the ages and two have chips broken from them. I don't have any problem with staining my teeth are fairly white. My bottom teeth don't have any issues really it all just seems to be my top.