[GA] Orthodontia coverage question

So I’ve been searching for the right dental insurance for me for a while and I have some questions. So my primary concern is that I need orthodontia. It seems like in every plan I have looked into they all have a 12 month waiting period for orthodontia, which stinks but is understandable. Unfortunately, I’m probably going to need to get braces sooner than that 12 month period. So my primary question is, if I go ahead and sign up for one of these plans and get braces, once I’ve had that plan for 12 months, will my insurance kind of kick in and start paying for my braces? Or will they say oh you got braces before your 12 months, so we’re not paying anything at all? I realize all insurance plans and companies are all different, but I thought I would ask here if anybody has any experience with this.
The only companies I can find so far that will cover orthodontia for adults in my area are Delta Dental and Cigna. And I think Humana has some kind of savings plan for orthodontia. But I’ll take suggestions too if they’re allowed here