Man, I love making a correct prediction!
Back in 2017-ish, there was a whole debate on whether or not theropod dinosaurs generally had extra-oral tissues that covered their teeth.
I, and a few other people into vertebrate paleontology, including tyrannosaur experts, predicted that large tyrannosaurids like
T. rex had extra-oral tissues, and that popular, toothy depictions like you'd see in
Jurassic Park and other movies are moreso a cultural anachronism, not a biological one.
That is to say, the animal didn't look like that in reality.
The reason they, and I, made such a prediction?
The presence of foramina (little holes) in a row near their tooth row, which, for reptiles, exists for one purpose, blood supply to tissues, and depending on how tight the facial muscles of the animal are, you'd smile like a crocodile, or look more like a monitor lizard.
For the former, you'd get a rough skull shape, with
lots of foramina everywhere. For the latter, you'd get particular foramina in a neat row along the maxilla.
T. rex, and other large tyrannosaurs more generally, and even more generally, theropod dinosaurs,
probably had extra-oral tissues that obscured their teeth.
Well, that prediction was confirmed to have evidentiary basis! Gotta love it!
Here's the study in question.
Here's also the skull of a
T. rex. Look along the tooth row, and you see lots of small holes in a nice, neat row. That's there because there was tissue covering that area.
There's a lot of interesting things about osteological correlates in
T. rex, and if you wanted to know, you can always ask.