The only thing that is proven to move the skeletal portion of the maxilla forward as an adult would be something like MSE+Facemask, but you'd be lucky to gain more than a couple mm's, other than that there's jaw surgery.

Some palate expanders can slightly move or expand the upper teeth forward a little, but this is dental expansion.

@falsenegativesleepstudy

what are your thoughts on Facemask alone? Why would the suture need to be split for the face mask to work? Say if someone already has a wide palate. 

Also do you know the usual force involved for face mask? How hard does it pull? 

@robbie343

It's not the suture split itself that makes face mask effective, it's the loosening/activation of all the sutures in the maxilla. 500-1500 g of force is used usually.

@sinned

gotccha makes sense. What’s the usual wear time for face mask? 

@robbie343

Facemask alone would likely just cause a dental rather than skeletal change if you anchored to the teeth.

https://pubmed.ncbi.nlm.nih.gov/32686018/ - Study done on patients age (18 +- 3 years)

Conclusions: MSE appliance performed almost parallel expansion in the axial view. Remarkably, this study shows that pterygopalatine suture can be split by MSE appliance without the surgical intervention; the disarticulation of pterygopalatine suture was visible in most of the patients.