My son was diagnosed too old to be offered bracing, so I never had to go through trying to get a teen to wear a brace. But I've followed the (so far) very muddy research on bracing, and was left with the sense that it was effective even though the research wasn't very clear.
The problem with the research was that patients weren't randomized. Basically, that means that it was possible that people who wouldn't progress were over-represented in the bracing group, and that bracing then just seemed more effective because of this.
So they did the first big randomized study of bracing in the US and the results were so conclusive that that had to end the study because, ethically, they couldn't continue to assign patients to the non-bracing group.
Here's a link to the research plus a New York Times article
The results are:
In the bracing group, 72% didn't progress to surgical range while in the non-bracing group only 48% didn't progress. The numbers got better the longer the brace was worn, with 90% of the kids wearing a brace more than 13 hours a day not progressing to surgery - almost twice the rate of the non-braced kids.
This still leaves lots of issues open - like, how many of the braced kids will need surgery as adults, and are there other downsides of bracing, and what's the trade off in psychological cost of bracing.
Bracing is a very individual choice, and some kids just aren't going to be able to do it. There's lots of things to balance. But I think this will make it easier for parents whose kids are bracing to feel like there's some point to encouraging their kids to weather it through.