You may not see the battle, but your mouth is under siege. There are more than 600 species of bacteria that may call your mouth home. They can cause plaque buildup, gum disease and all manner of problems. Sure, there are some good bugs in the mix that kill bad bacteria, but many of them are very bad guys. Beyond the legions of bacteria invading your pearly whites, eating foods that are high in acid can erode the enamel in your teeth, too, leaving them more vulnerable to tooth decay [source: Cromie].
As if all of this weren't enough, eating the wrong foods can lead to tooth and jaw problems -- painful cracks, cuts, gouges, chips and jaw injuries, like temporomandibular joint disorder (TMJ). We're talking about accidents involving foods that look delicious and oh, so inviting, but can wreak havoc on your unsuspecting teeth and gums.
On the next pages, let's take a look at the "most unwanted" list when it comes to hard foods your teeth won't see coming. You can probably still eat them on occasion, but use restraint, because these foods can be trouble.