system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we put braces on kids who still have some/all baby teeth?
gpt
Are you seeing brackets (the part cemented to the tooth) on baby teeth?  If you're talking about braces while some baby teeth are still there, the orthodontist is probably just getting a head start on the adult teeth and making space for new (larger) teeth to come in. 

If you're seeing braces on the actual baby teeth, they're likely trying to deal with something other than crooked teeth. For example, fixing an over or under (or cross) bite.