Our son push his two front teeth up into his adult teeth when he was jumping from a wall to a trash can at a friends house (and just told me he triped and fell, but later felt he better come clean, lol) and he fell between the two trash cans, back then they were metal. They just kept an eye on them and waited to see how he would do. It did take a little longer for his adult teeth to come down, but he was fine. I fell when I was 18 monthes old and broke my front tooth and they had to pull it, I know I did not have a front tooth until I was 7 or 8, the new one came in fine my gum was a little higher, but it did come down to meet the other one.