Orthodontics is simply “making a retainer” the same way orthopedics is simply “putting screws in a leg”.

The difficult part is not the manufacturing, but knowing how to do it properly so you don’t harm the patient.

Sure, but it's a more or less a formulaic process. There's not on the fly decision making or emergency responses like in orthopaedic surgery or any other surgical design. You make a mold or scan of teeth. Calculate the adjustments, make the retainer, repeat. With a more widely available tooling the process could be even more monitored. i.e. Bi-weekly instead of monthly molds for faster and more precise results.

As the joke goes, $10 to tighten the bolt, $90 to know which bolt to tighten.

>The difficult part is not the manufacturing, but knowing how to do it properly so you don’t harm the patient.

And yet I read plenty of horror stories of bad orthodontic results. Ask me how I know.

Went to 3 different orthodontist to fix what a bad orthodontist did to me when I was a kid, and each gave me a completely different treatment plan. I feel like being an orthodontist is just eyeballing and patching your way as you go to an acceptable resolution.