In the German "General" part of this forum the existence of wired-in headgears was claimed. On the other hand it's been said wired-in headgears to be applied almost just in Brazil and the USA. (https://www.bracesforum.net/smf/allgemein/fixed_headgear-t4653.0.html;msg36585#msg36585)

Up to the moment an evident proof for the existence of wired-in headgears is missing.

Is there any possibility to give a proof for it? Do you know any pictures showing or orthodontic websites mentioning it?
Or do you just know anyone to be treated by wired-in headgear?

If available, please post any information as far as it is suitable to proof that wired-in headgear to be authentic.

Asking in a rather indirect way, I was told by my dentist who is also an orthodontist  that he thought such a thing might well have occurred during the 50s and 60s when as he put it: orthodontics was far more focused on bite correction rather than patient welfare. Sorry, I know this is a bit vague.

I asked my orthodontist this question and he said it's illegal to wire in headgear. 

It appears those who write that this happens to them, are having a fantasy experience at the time!