If you’ve ignored your dentist’s pleas to floss more, you’re not the only one. According to a recent analysis of national health data, nearly one-third of American adults skip this simple (yet oh-so-important) oral hygiene practice on a daily basis.

U.S. News & World Report recently interviewed lead author Duong T. Nguyen, a medical epidemiologist who works for the Centers for Disease Control and Prevention. Nguyen was involved in the National Health and Nutrition Examination Survey (NHANES), a representative look at Americans’ health habits based on interviews and physical examinations of 5000 people a year. 

According to U.S. News, Nguyen noted that no “rigorous, scientifically valid analysis” had ever been conducted to learn how many people in the U.S. actually floss. So he and his colleagues focused on the survey’s section about flossing, in which participants self-reported how many times they flossed the week before. In all, they examined NHANES data from 9056 US adults, ages 30 and up, who engaged in the study from 2009 to 2012.

After accounting for factors like age, sex, race, and income, the researchers found that only 30 percent of the population flosses daily. Meanwhile, just over 37 percent of respondents reported flossing less than daily, and 32 percent flat-out didn’t floss at all. 

Other interesting findings? Men were more likely to report never flossing than women (39 percent compared to 27 percent), and individuals ages 75 or older were more likely to report never flossing than respondents who were ages 30 to 44. Non-Hispanic black and Hispanic adults were also more likely to report never flossing than non-Hispanic white adults, as were low-income participants when compared to ones with higher incomes.

Why do some people floss while others don’t? Nguyen boiled it down to education, telling CNN that primary care physicians and dentists alike needed to reinforce the habit’s importance to their patients. "Repetition is the key to mastering," Nguyen said. "If you hear it more and hear it from different places, maybe it will stick a little more."

"I think it's one of those things people don't know enough about," Nguyen continued. "We are telling people to floss, but if we don't tell them why and what it prevents, that could be one of the barriers. We need to improve health practices and make sure people understand something as easy as flossing can prevent a whole host of other dental issues for you as you age and grow up."

For many people, flossing is an after-thought. However, experts say it’s the most important part of cleaning your teeth. When you brush, you’re not reaching all the food between your teeth that causes the buildup of plaque. Plaque contains bacteria that cause cavities and gum disease. If it’s not removed daily, it can harden into tartar, which can eat away at your teeth and gums. 

Want to start flossing, but worried that you won’t stick with it? Try flossing before brushing, instead of the reverse. That way, you’re getting the tedious task out of the way. Plus, some dentists say that if you floss first, you stir up the particles and plaque that the toothbrush can brush away (although others argue that it’s better to floss afterward, since the floss can push the fluoride from your toothpaste between your teeth.)

But no matter which way you choose to floss, just remember to do it once a day. In short, don't be among the third of American adults who don't perform this essential teeth-cleaning step.

[h/t U.S. News & World Report]