Your mouth really is filthy! It's a saliva bath for millions of tiny little creatures that share your food, chew holes in your teeth, and make your breath smell like a garbage truck. From cavities to canker sores, those little creatures can also create some repulsive problems. Learn all about saliva, plaque, and the bacteria that infest your mouth - and find out how to keep that mouth of yours healthy. With close-up pictures and lots of disgusting facts, this book tells all about the gross science behind your body's functions.