Yeah mouth breathing causes so much chaos, its insane.
I’m not sure if I can post a direct link to what I use, I don’t want to break any rules here. But I can tell you it’s based on the Myobrace A1 design. You can DM me if you want more details.
I can tell you this. These appliances are nothing special, essentially just rubber mouthguards. The mechanism of action is raising the dental height and releasing the soft tissue that’s been sort of locked. Also increasing mobility of the jaw and allowing more planes of movement. There is some slight rearrangement of the teeth as well. That’s the theory at least, I’m relatively new to some of this stuff. You just have to sleep in it, so you have to make sure it’s a relatively comfortable one (although there’s gonna be discomfort at the beginning stages)
So if you wanted to give it a run with something cheap you could try that first. I think the myobrace A1 runs like 60 bucks on aliexpress though. So by the time you go through cheaper rubber appliances trying to find a good fit you might spend more money in the long run since this whole thing is hit or miss.
Also as a disclaimer like in that video you posted conventional dentistry usually doesn’t recognize a lot of this. And it’s a toss up of what facts you can find online vs what’s pure pseudoscience. Hence me just experimenting with it and drawing my own conclusions cuz it’s the wild west lol.
Really good video if you have the time. This will explain how your jaw and teeth can cause a whole chain reaction throughout your body causing all types of asymmetry and postural dysfunction.