This NY Times article (paywall workaround here) talks about why it's a good idea to teach kids the anatomic names for body parts instead of using nicknames. 
But while those safety issues can loom large for worried parents, she said, the most important reason to teach children the right words for body parts -- their own and those of others -- is more positive and more profound. "It helps children develop a healthy, more positive body image, instead of using nicknames that their genitals are something shameful or bad," she said. "It also gives children the correct language for understanding their bodies and asking questions about sexual development."