Some parents allow their children to have small steel balls on the top or bottom of their tongues. To have the little steel balls stay, the tongue has to have a hole in it, much like a pierced ear.
Oral piercing can cause a lot of pain, swelling, infection, drooling, loss of taste, scarring, chipped teeth, and tooth loss. Most dentists discourage oral piercing because of these risks.
How can oral piercing be bad for you? Because your mouth contains millions of bacteria, your tongue may be exposed to more bacteria, causing it to swell and even partly block your windpipe, or airway.