I've received a bit of skepticism. When I spoke to my dentist, he said he didn't... I think he was looking for an anterior tongue tie, which is fair because that is what, as a non-trained person, I (and I think most people) expect to see. He was uncertain and said he had heard the term "posterior tongue tie," but he didn't really believe that it was a thing. And that's okay; we're allowed to have our own belief systems.
I've had a consultation with one now and have been told ‘yes’ I have a tongue tie! My tongue is tied in the middle and posterior of it, so the front part is not tied, but the rest of it is basically. So it's really, really nice to be told, and that sounds a bit weird, but to be told for certain yes, you do have one. I now can make steps to get treatment.