I have made a big upgrade to my facepulling headgear over the past few months. The frame of the device now rests on my chest and shoulders, allowing me to load more force on my maxilla. I have built this new frame using a medical neck brace to which I added metal poles. This is inspired from The Crane but it is a better design for a fraction of the cost.
My previous design looked like this:
My new headgear looks like this:
The forces applied on the maxilla are shown in red:
This is used with the same intraoral appliance as before:
I can sleep a full night with 500g of forward force and 500g of upwards force on my maxilla. When I raise this to 1000g forward and 1000g upwards, my palate becomes sore and I have to remove the headgear. I am working on making the intraoral appliance more comfortable so that I can apply higher forces. The most important design aspect of this appliance is that all of the load is applied on the maxilla, with zero teeth contact. This is important because the teeth can easily be displaced if forces are applied on them. We want to displace the maxilla while leaving the teeth untouched.
The facepulling headgear is only half of the battle. To achieve maxillary protraction in an adult, you need to develop excellent tongue posture and chewing habits. This is done by chewing hard gum regularly and practising tongue posture on a full-time basis.
We know that maxillary displacement is possible in adults, as Dr. Won Moon has been doing non-surgical palatal expansion on adults on a regular basis. Here is one of his results on a 30+ years old patient:
There is an interesting paper that shows the effect of a reverse-pull headgear on a 20-year old female. In these kind of experiments, the method used to to protracting the maxilla is very important and can be the difference between a successful case and a failure.
Usually, facemasks are only used on growing children and attempt to change the direction of growth. As adults, we do not have growth on our side so we have to stimulate bone movement with high forces and long wear times.
This 20-year old woman wore a reverse-pull facemask attached to her braces for 20 hours a day during 4-months. One of her main concerns were her underdeveloped cheekbones, that she wished to improve with a more forward maxilla.
“Her upper lip was slightly retruded. She presented with maxillary hypoplasia and flat malar (cheekbones) eminences.”
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.