Watching them do the chair was... terrifying... Just seeing the rigging they used stretch and jump up in 200lbf increments gave me sweaty palms.
I had to get an MRI at the start of the year and told them I had metal permanent retainers and was slightly concerned. They were like "Nah, you're fine." I was like "Okay, just please don't steal my teeth 😬"
This appears to be a variation of the "standwich." Please see the attached for an example.