S.W.
Hi A.,
My oldest son, now 3.5, has an under-bite that probably won't correct itself. My youngest son, now almost 2, had one that corrected itself. Unless it's significant, you probably won't be able to tell which way it will go at 17-mo's. And even if it turns out that it doesn't correct itself, there is nothing that the dentist can do about it until the child gets older. Hopefully we'll be able to correct my son's with braces. But if not, we'll probably be looking at surgery to realign the jaw. Although I hope that we don't have to go down that path, it is not worth worrying about now - be proactive, but take it as it comes and hope for the best! Good luck!