Every year Delta Dental conducts a survey on the average cash gift the “Tooth Fairy” leaves for children who have lost a tooth. Like everything else its gone up – to a record $5.36 per tooth, the highest in the survey’s 24 year history says Senior Manager of Corporate Communications for Delta Dental Virginia, Jeremy Butterfield. Monday is “National Tooth Fairy Day.” Butterfield says the event – held twice a year – is also a good reminder to visit the dentist on a regular basis for checkups.