Any ideas for a dental mouth gag for a tiger?

In veterinary medicine, we use a dental gag to hold the mouth open while we work inside the oral cavity. We’re doing surgery on a tiger next week (she has an abscess on her tongue, probably some sort of foreign body in there that we need to find), and I need to come up with something on the fly. I’m thinking that I could cut some lengths of PVC pipe (an upper canine would fit into one end, and a lower canine tooth in the other, propping the mouth open), but because this is a geriatric cat, I’m worried that her teeth will be too worn down (or even broken off) to securely seat in the PVC opening. (Yes, the cat will be anesthetized during the procedure.)

Any creative ideas, guys?