After orthodontic treatment usually space fills so no need of any prostheses. But if there is space then first consult your orthodontist and wait for few months.

Firstly need to know whether their is any space left for them or not. Because if they are removed for orthodontic treatment then might be their is  no or less space for them. Wait for some years then go for implants if you want to. No they won't cause any problem in normal growth but it's better to wait.

Hi... To begin with we need to know if you have space left for those teeth now or not as you have mentioned that you got them removed for braces so most probably you would have completed your treatment and the spaces would have closed. Furthermore yes we usually wait for about 17-18 years of age for placing the implants but it is not always the case since every individual has different age of development. You need to visit an oral surgeon and they’ll guide you.