I found a very interesting study showing that maxillary displacement is possible in adults. Researchers applied 500g of force to the maxilla of adult monkeys through a teeth anchored appliance for 3 months. They then determined the maxillary displacement with the help of bjork implants. This is a very reliable technique, and it proves that facial bone movement is definitely possible in adults.
This is the Vitallium splint that was used. As you can see on the picture, it is tooth-anchored.
The monkeys were immobilized in a headgear for a duration of 80-91 days
The theory behind a facepulling headgear is rather simple. You want to apply constant forces on the palate to move it forward, upward and to expand it. Creating a headgear that is light enough to be worn for hours and that is comfortable enough to sleep with is the challenge.
First, there is the forward force. The biggest surface to apply this force is the anterior region of the palate, from where it will drag the maxilla forward. A forward force alone is problematic, because it would rotate the maxilla in a counter-clockwise direction and disrupt a healthy bite.
In the Summer of 2014, I had this idea idea for the first time. I will create a machine that pushes on my maxilla to move it forward. This force can be replicated by sticking your thumb on your palate, and pushing forward. If you do it for several seconds, with a high enough force, you feel a strain on your cheek area, just below the eyes. I simply needed to create a machine that will replicate this force, and I would wear when sleeping or at home. The concept is simple, but implementation has turned out to be pretty challenging.
I got my hands on a meccano set, and immediately built this contraption. It was heavy, uncomfortable and impossible to sleep with. It put so much reciprocal force on my forehead that it would wrinkle my skin and give me headaches. I still tried to wear it as much as possible, but it needed a lot of improvement.
I also found the initial design sketches I made, when I first got this idea. This is what I tried to build with the meccano set.