Facemask Therapy in Kids for Underbites

Here’s what you need to do to start facemask therapy in a growing patient with a retrognathic maxilla:
(note links are just suggested- you can buy from any vendor):

Buy it from ebay (or any ortho company) https://www.ebay.com/itm/J-J-Ortho-Orthodontic-Protraction-Facemask-Reverse-Headgear-for-Underbite/221863787243?hash=item33a81cbaeb:g:soQAAOSwoRFdFsW3
Also need extra oral elastics: https://www.pearsondental.com/catalog/product.asp?majcatid=744&catid=6538&subcatid=26057&pid=79161 or https://www.henryschein.com/us-en/Search.aspx?searchkeyWord=extra+oral+elastic
I usually do 8oz 1/2 inch but some people do 16 oz but you can always work up to that if you aren’t seeing results.
So around $50 ish  and the elastics can last for many patients.