How many times have you bitten into an under-popped popcorn kernel and felt it violently clash with your teeth. For a split second you worry that the kernel actually damaged the tooth and you swear you’ll never eat popcorn again. But then you realize that you’re fine and continue to pop another piece in your mouth. But with each bite, you expose yourself to that risk; next time, you might not be as lucky.
Unpopped kernels are not the only concern, however. Even a popped kernel will leave its hard hull behind inside soft starchy exterior. There have been several documented cases of the hull getting lodged in the gums and causing infection. In at least one case the infection almost cost a man his life (https://www.medscape.com/viewarticle/923650).
Let’s say you do survive the onslaught of unpopped kernels and sharp hulls. Now you have cavities to contend with. Popcorn is mainly carbohydrates, the favorite food for cavity-causing bacteria. This is made even worse if the popcorn is in the form of a Cracker Jack and is covered in sugar as well.
These facts haven’t stopped people from enjoying popcorn, but armed with this knowledge, you can mitigate some of the risk involved.