Never heard the expression. Grew up in the south, if that matters.
Still gonna call it pizza crust.
Have heard the term exactly once…some friends of my wife’s aunt and uncle called the uneaten crusts “pizza bones”, and did, indeed, give them to the dog.
Never heard it before, though from context I figured out exactly what it meant. I think I still prefer to call it “crust”. And I happen to love it, so our dogs generally don’t get any of mine anyway.
A third hand in the air here.
I’ve heard people say it a few times in person, maybe 5 times? It always struck me as one of those expressions that was cute to hear someone else say, but it would never occur to me to start using the expression myself.
I think I heard it once before a while ago. I still think it sounds asinine.
I voted heard/never use it when the reality is used to use it and haven’t in many years. Then I started to wonder why and I think this is why. I haven’t lived with a dog for a long time.
Took me a minute, but yeah. Not a term I use much, as “crusts” usually seems clear enough.
Southern Ontario. Never heard it before this thread, but I’m sure as hell using it from now on, 'cause it’s a great word.
Yep, my dogs love the pizza bones.
Grew up in central Indiana and knew the term, though I knew only one family that used it, transplants from Pensacola, Florida. Seems to me that most natives here simply call them “crusts.”
I’ve used it myself, but it was more of a joke than anything. I’d never heard of anyone else using it but the people I said it to. I’m pretty sure the context was telling them that the bones were good, too. They’re perfectly edible breadsticks. If you need sauce on it, dip it.
The reason I don’t use it often is probably because I like them. And people at least know what I mean if I call it the crust.
I’d never heard it until DH and I became friends waaaay back when we were 18. I still eat his bones on a regular basis. 
This is the absolute first time I’ve heard the expression. Guess it’s not so common in my part of Canada.
In the “know it but don’t know why I know it since I can’t recall ever personally experiencing it being used” camp. Raised in the Pacific Northwest, a few years in Hawaii, 13 years in San Francisco area.
At least for me it is a concept without much purpose. If a pizza crust isn’t good enough that I wouldn’t want to eat all of it then I won’t be eating any of it. And when that happens what is left on the plate is just called “bad pizza.”
So it is hard for me to imagine to regularly leaving the edge of the crust uneaten that a term would develop for it.
To me, the taste of the crust edge is sometimes, but not often, divorced from the taste of the rest of the pizza in New York style ultra-thin slices. Where the dough’s thin it’s great as a sauce and cheese delivery mechanism but at the edge it can be dry and hard (but not always).
I guessed it referred to the crust, but it doesn’t make sense because bones aren’t eaten but pizza crust is.
In the context of a dog getting them, I would have guessed that it meant crusts. But absent that context, I was thinking it meant those little plastic tables that get stuck in the middle to prevent the box from collapsing.
The people I know who use the term are the kind who consider the edge crust to be unfit for consumption.
I heard it used when I attended college at Ohio University in Athens. Never before or since.