I think it all depends on what else you are comparing with, plus pain is in part psychological, which is why people are offered therapy as part of pain management.
I think for the sheer uncertainty of outcome fracturing a vertebrae in my back and being on bed rest for a week before an operation was probably the worst, despite all the morphine.
Having said that a prolapsed disc with sciatica was also very painful, though again - free drugs. The recovery time was longer, so it raises more questions in your mind as to whether you will return to 'normal', likewise a frozen shoulder.
Tooth abscess and labour were never more than a couple of days and with somewhat more certain outcomes, so easier to deal with mentally.
Psychologically I have found humour the best approach, obviously try to avoid laughing yourself with a fracured spine, but if everyone around you is looking glum and worried it makes you feel worse. I think it also makes the hospital staff more positively disposed towards you. Obviously only once it is clear to them that you are genuinely in pain and you have a diagnosis. You can't do a full standup routine with a fractured spine, just the odd joke here and there.