While that girl may appears to have actually needed braces, they are still basically the ritalin of my generation. Something like 2/3 of my 7th grade class had them, and now as adults the same 2/3 all have issues with cavities and their jaw mechanics. You may need root canals in your 20s but at least no one will ever see you smile with your front teeth two millimeters out of alignment!
It could be coincidence, but I think you can at least propose that being unable to brush properly for two years and having torque placed on your jaw to realign it lead to problems with cavities and your jaw down the road. If it's something that gives you problems with chewing or whatever, it might be worth it, but otherwise it seems like we're causing a lot of bullshit for little gain.
Of course, of course... I didn't mean to imply the therapy would be needed solely due to the braces. Years of being ridiculed for having fucked up teeth was definitely considered. As was the trauma suffered when she realized that even with straight teeth she was still going to be rejected by the cool kids. And then there was that uncle with intimacy issues, but now we're getting away from the teeth, which is our focus here today.