I believe the teeth will continue to move a little after they first come through before finding their permanent spot. My brother & I both had our adult teeth come in behind our baby teeth & we both have perfect teeth as adults (no braces).
Surviving sleep deprivation one day at a time with dd (Oct '11) & ds (Oct '08).
I hear a lot of movement happens, my daughter's bottom permanent tooth is coming in at QUITE the odd angle, I'm hoping it twists a lot. Not really helpful, exactly, but there are others hoping/expecting for movement after first eruption.