The going rate for lost baby teeth had major gains in 2013. In fact, according to Delta Dental's The Original Tooth Fairy Poll, the average gift from the Tooth Fairy climbed to $3.50 last year, up from $2.42 in 2012. This 44.6 percent rise surpassed the outstanding performances of the major U.S. stock indexes.

The Original Tooth Fairy Poll has generally been a good barometer of the market's overall direction. In fact, the trend in Tooth Fairy giving has tracked with the movement of Standard & Poor's 500 Index (S&P 500) in 10 of the past 11 years. In 2013, the S&P 500 gained 29.6 percent, its best annual performance since 1997.

"As leaders in the dental benefits industry, we keep our eye on all kinds of economic indicators," said Jennifer Elliott, vice president of marketing at Delta Dental Plans Association. "The Tooth Fairy's record giving tracks with big gains in the stock indexes in 2013."

First Tooth Has Higher Valuation

Delta Dental's survey found that the Tooth Fairy was even more generous for first-time tooth giving, leaving more money for the first tooth than for other teeth in 59 percent of homes. On average, the amount given for the first tooth was $4.51. This is a 29.2 percent increase from last year.

Other findings from The Original Tooth Fairy Poll, which surveyed more than 1,000 parents nationwide, include:

• The Tooth Fairy visited 86 percent of U.S. homes with children who lost a tooth.
• The Tooth Fairy left cash for kids in 98 percent of the homes she visited. Two percent of children received toys, gum or other gifts.
• The most common amount left under the pillow by the Tooth Fairy was $1 (42 percent received this amount).
• Twenty-eight percent of kids hit it rich and received $5 or more for each lost tooth.