DS1 is 10 yo now, but had orthodontic treatment between age 7 and 9yo.
Not Myobrace, but a small removable wire brace that gently guided the growth of his narrow palate to expand it. He also wore headgear at night to help "draw out" his underdeveloped mid face (you wouldn't have noticed unless you knew what you were looking for)
His high narrow palate was caused by a posterior tongue tie, so he had that lasered before he started the treatment. Within a couple of months, I could see his cheekbones emerging, his snoring and apnoea stopped, his mouth breathing stopped and he was overall a much happier kid. You don't mention any of these problems, but I mention it because there's more to having good orofacial structure than straight teeth.
Anyway, without this treatment, he would definitely have been looking at multiple extractions and problems with his bottom jaw. Mouth breathers tend to have a longer lower jaw because the growth is affected by the mouth being open all the time.
Fast forward to now and he is no longer wearing his braces and the orthodontist has said that he might not even need fixed braces, but we need to see exactly how his adult teeth emerge. If he does need fixed braces, it will be a very simple job with no extractions required.
I would recommend seeing John Roberts at the Cote Royd Dental Practice in Huddersfield. He did ds1's tongue tie for us, but not the orthodontics because we live 200 miles away!
I cannot emphasise enough how glad I am that we did this for DS1. In our case, his sleeping, eating and breathing were being affected and it made a world of difference for him.