Brushing and flossing your teeth on a daily basis isn’t just for aesthetic reasons — clean teeth and healthy gums are essential to health and wellness, says the World Health Organization (WHO). But it doesn’t look like everyone has gotten the memo.

According to the WHO, 60 to 90 percent of school children and nearly 100 percent of adults have dental cavities. Fifteen to 20 percent of middle-aged adults have severe periodontal (gum) disease, which is a known risk factor for tooth loss. And a recent report from the American Dental Association found more than 100 million Americans fail to see a dentist each year despite the fact annual checkups can help prevent most dental diseases.

Less frequent visits to the dentist compounded with poor dental care doesn't just lead to a ghastly oral appearance, but it adversely effects general health. Enter National Dentist’s Day. The unofficial holiday not only aims to show appreciation for dentists, but to reduce the nerves and anxiety people feel ahead of their next cleaning. For some motivation, here's what you get when you take a trip to the dentist's chair.

Disease prevention

Dentists can determine whether you are developing a serious disease like diabetes by just looking at your teeth, according to Delta Dental. The idea is "diabetics may experience diminished salivary flow" and a burning sensation in their mouth or tongue, which can cause tooth decay. Not to mention uncontrolled blood sugar levels can have an adverse effect on oral health, particularly gum recession or shrinkage.

It's not just diabetes: Previous studies have shown that more than 90 percent of systemic diseases — diseases that involve many organs or the whole body — have "oral manifestations," including bleeding gums, swollen gums, mouth ulcers, and dry mouth, Delta Dental reported. It's also been well documented those pearly whites can be reflective of bone and mental health, as well as a person's risk of developing dementia, stroke, and coronary heart disease.

What's more, oral infections, such as gum disease, are thought to increase risk of preterm birth, oral HPV and cancer. And yet, the care people need to prevent these diseases doesn’t start and end with the dentist.

Reduce oral bacteria

Like many areas of the body, the mouth is teeming with entire colonies of bacteria, according to Mayo Clinic. One 2005 study estimated there were m ore than 700 bacterial species in the oral cavity. You can’t see, feel or taste them, but they’re there—and while most of them are harmless, there are some species capable of causing disease.

When bad bacteria thrives in the mouth, it causes plaque build-up, cavities, and gingivitis, which can lead to periodontal disease — one of the most common oral bacteria infections. As Medical Daily previously reported, oral infections allow bacteria to travel through the bloodstream to the heart and arteries, where it elevates cholesterol and triggers inflammation.

The WHO reported risk factors for oral diseases can include an unhealthy diet, tobacco use and harmful alcohol use; however, these vary across "geographical region, and availability and accessibility of oral health services." WHO found oral disease and infection is an increasing probelm in low- and middle-income countries, "and in all countries, the oral disease burden is significantly higher among poor and disadvantaged population groups."

No Plaque

Daily brushing and flossing can keep bad bacteria under control. The fluoride in toothpaste helps protect teeth from decay by removing plaque from its surface. And floss gets at the tooth decay-causing bacteria that may linger between teeth where toothbrush bristles can't reach.

It’s important to do this twice a day—and not many Americans do, according to one survey that found more than 30 percent of Americans only brush once a day. But not brushing your teeth for a second time can "start the process of a cavity…especially if your occasional forgetfulness is more frequent than you'd like to admit," the Huffington Post reported. Already by mid-day there's plaque on the teeth.

"In the middle of the day, [run your tongue] across your teeth right around the gum line. You’ll find something sticky or fuzzy," ADA spokesperson Deepinder "Ruchi" Sahota, a dentist in Fremont, Calif., told HuffPo. "That's plaque."

Thus, the ADA's twice-daily brushing and flossing recommendation is no joke (the exact technique is still up for debate). People should brush their teeth once after getting up in the morning and again before bedtime for two minutes with a soft-bristled brush that should be replaced every three for four months. The ADA also recommends flossing afterward to help remove plaque and food particles between the teeth and under the gum line.

Oh, and whatever you do, don't fall for these dental care myths.