If you’re still a dental student right now, I would continue building rapport with ortho faculty/other faculty in order to get recommendations for the next cycle. Continue participation in ortho-related activities or other leadership/volunteering roles to strengthen your application. Begin to re-work your personal statement to make it stronger. Think of this next application cycle both as an opportunity to build off of what you have learned from this past cycle and also as a clean slate. Once you start a job, try to get involved in ortho related activities through things like CE courses. Begin to note down interesting experiences you have with your patients both in school and at work so that you can use them as examples during your interviews. If you didn’t have a high GRE score, consider retaking the exam. Also, if you didn’t apply very widely this past cycle, apply more widely this year so that you maximize the number of interviews you can get.
If you’re already a GP right now, again try to expand your scope a little bit to include ortho-related procedures through CE. If you have time, maybe find an ortho office that’s open on weekends and shadow/assist there. I personally do not know too much about what it’s like to go the non traditional route (I’ve gone straight from college to dental school, and now straight to residency), so reaching out to someone who got in as a non traditional applicant may be better to get advice.
It really just boils down to this: you don’t want your application to stay static. You need to improve your application from the last cycle as much as you can. The schools want to see that you self-reflected on any mistakes that you made the previous year and worked hard to improve on them. Show growth and a commitment to the specialty. Hope that helps!