When a dentist tells us something is wrong with our teeth, we tend to follow their advice. But when Mona visits two different dentists, they give her two wildly different diagnoses (with wildly different price tags). So how do we know who's telling the tooth? Mona digs up the dental data to look for answers, and finds that in reality, the study of dentistry is riddled with holes. Also, a quick favor! We're doing a survey on listeners of Am I Normal? with Mona Chalabi. If you have a few minutes to help us improve the show, it's at surveynerds.com/aminormal. Thank you!