NewYork-Presbyterian. The University Hospital of Columbia and Cornell.

-- Neglected oral hygiene brings to mind problems like decaying teeth, swollen gums, and bad breath.

But medical experts say an unhealthy, bacteria-filled mouth can also lead to a host of problems throughout the body, such as heart disease, diabetes, blood infection, and even low birth-weight babies.

And the culprit, more often than not, is gum disease.

"When you're looking at people who have gum disease, they are suffering from a chronic low-grade infection," says Jean Connor, a dental hygienist in Cambridge, Mass., and president-elect of the American Dental Hygienists' Association. "Your whole body is a little bit compromised."

October is Dental Hygiene Month

That is why dentists and hygienists are taking the month of October, which is National Dental Hygiene Month, to urge people to consider the deeper risks of not caring properly for their teeth and gums.

A growing body of research is finding that gum disease - sometimes called periodontal disease - can worsen numerous health problems. And it is not something that just affects a few people. Four of every five Americans suffer from some form of gum disease, according to the National Institute of Dental and Craniofacial Research (NIDCR), part of the National Institutes of Health (NIH).

Inflammatory Response is Key Factor

Gum disease ranges from gingivitis - a mild and common form that causes inflammation of tissues around the teeth - to more serious forms like periodontitis, where the inflammation affects the connective tissue supporting the teeth.

The bloodstream links organisms in the mouth to the rest of the body. Bacteria from the mouth flood into the circulatory system and travel to other parts of the body, causing a widespread inflammatory response.

Another explanation is that oral infections trigger the immune system, producing inflammation elsewhere in the body.

"If you had an infection in your finger and you left it, it eventually would affect the rest of the body," Connor says. "It's the same with your mouth."

Gum Disease and Other Medical Conditions

Recent studies have shown an increased risk of heart disease and stroke in people with gum infections, according to the Centers for Disease Control and Prevention (CDC). The risk appears to increase with the severity of the infection.

"Gum disease produces a tremendous amount of bacteria," Connor says. "If you have a valve problem with your heart, the bacteria can invade and infect the heart."

There also appears to be a link between gum infections and diabetes, as people with diabetes are more likely to have periodontal disease, according to the CDC.

Researchers are now looking into whether there is a two-way connection between the conditions to see if diabetes can be better controlled through treatment of gum disease.

Other researchers have found that women with moderate-to-serious gum disease are twice as likely to give birth to premature babies. Problems ranging from low birth-weight to birth defects can result.

"If you are pregnant and you have gum disease, there may be problems in your pregnancy and with birth," says Diann Bomkamp, vice president of the American Dental Hygienists' Association.  A gum infection takes a toll on the immune system and pregnant women are already susceptible to a host of problems due to the stress of pregnancy and childbirth.

It Is Never Too Late to Floss & Brush

An estimated 20 percent of Americans have periodontitis, and it is the primary cause of tooth loss in adults.

Regular and thorough brushing and flossing is the first line of defense against gum disease, Bomkamp says. A healthy diet without sugary snacks and sodas is another step toward preventing gum disease and other associated conditions.

Additional tips for preventing gum disease include:

• having regular dental check-ups
• not sharing drinks with children if you have gum disease
• not blowing on your child's food to cool it down if you have gum disease
• avoiding tobacco products
• limiting alcohol intake

Always consult your physician for more information.