I got the information for the health insurance at my new job. Almost every clause in a legal document comes from some bad thing that happened once.
The description of the dental document was interesting. “Cleaning – Limited to two times per consecutive 12 months.” That line was reasonable.
I was amused by “Tooth extraction – Limited to 1 time per tooth per lifetime.”
Who gets the same tooth extracted twice? Where did the “per lifetime” restriction come from?
Amazingly, some people have multiple sets of adult teeth. (example: http://bodyodd.msnbc.msn.com/_news/2008/11/25/4380059-the-boy-with-the-extra-set-of-teeth) Pull one out and another one comes in. Possibly someone with this incredibly rare condition had two extractions on a “single tooth” (meaning same tooth number), which rather than pay the $100 or whatever, they probably engaged in tens of thousands of dollars in legal expensese challenging, followed by the addition to the forms you saw.