An Old Habit Seems New Here's an idea that may be new to you. Did you ever think of brushing your tongue? Actually, tongue-brushing is an ancient practice. Our ancestors considered it part of their daily hygiene. Yet many people today aren't aware that their tongue needs brushing as much as their teeth do. In fact, it may be the dirtiest part of the mouth! Thousands of bacteria breed on the many tiny papillae (small bulges) of the tongue. And if they aren't brushed or scraped off daily, they can cause bad breath and re-infect your teeth with germs. So when you brush your teeth, brush your tongue, too—for a head start on a fresh breath.