R..
My daughter's crossbite (narrow upper jaw) was corrected when she was six. They put in a "butterfly"...a metal device attached to her upper molars that had a key I turned at home to widen her pallet. She was done with that in 21 days!!! Less than a month and her jaw was corrected. They left it in place for almost a year but it no longer needed turning.
Then they captured her teeth as they came in and with braces pulled them into place. She had many teeth that would have come in through the roof of her mouth had we not corrected.
Now I have to look at Myobraces to see if we missed out...but what we did worked great and wasn't super expensive.