Yeah, I know of all those ways to "improve" your application to ortho. IMO, those opportunities are very limited and some of those options take a lot of time - like doing a masters or an entirely different specialty. And none is a guarantee. Also, I don't think it improves your application if you don't have the stats to begin with. If you are competitive and didn't get in, it might show dedication.
I think a fellowship is a great thing for someone trying to get into Oral Surgery - 1)there are lots of them available to pursue. 2) If you don't get into OMS after a fellowship, you will still have learned a ton on how to handle more OMS procedures in your office. 3)They are also paid positions.
For ortho, I can think of very few "fellowships" - Florida (ortho), Chicago (cranio-facial), Vanderbilt (but not every year), Rochester (this is a TMD program though), Lancaster Cleft Palate Clinic (I think?), UConn (maybe?). Unless you're counting the TMD programs from that other thread as more "fellowships." Majority, if not all of these fellowships, you have to pay the institution tuition for the privilege of participating. When you finish, and if you don't get into ortho (it happens 🙁 ), do you really come away with any useful skills to add to your general practice? No, but you do have more debt now. IMO, a GPR which does full ortho in it would be a more useful way to spend the year. Of course, if you do make some connections and get in, it's worth it.