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: