Delta Dental puts together the Tooth Fairy Index every year and this year, has been a tough one on the little gift-giver. Delta Dental spokesperson, Chris Pyle told me, "The average gift from the nocturnal tooth-taker dropped to $2.10 in 2011. That's down 42 cents or 17% from the year before". The most common amount left by the Tooth Fairy is $1, although the first tooth tends to get substantially more than subsequent losses.