What is the definition of a "full mouth debridement"?

I ask, because this is what my NEW dental office coded my visit as, and I'm not sure I had anything "special" done to my teeth at the appointment. It had only been 9 months since my last cleaning, and I have received regular dental care my whole life, with very little buildup present at my 6 month check ups for the past 23 years. Thanks.
--------------------
A full mouth debridement, is basicly when you have build-up on your teeth, but not enough to be classified as "scaling & root planing" The dentist, or hygienist using the cavitron to knock off all the build-up, and then your supposed to go back a few weeks later for fine scaling. HOWEVER.. the hygienist I work with, just informed me that any time the cavitron is used (machine that squirts out water), it is technically called a "full mouth debridement" A full mouth debridement is more money than a regular cleaning, so I would call your dentist office and ask if this is something they do with every patient.
Source