If the eyes are the window to the soul, then the mouth may be the watchtower of a person's health.
Doctors believe there is a 90 percent association between the condition of the mouth and certain body diseases.
Ninety percent of all systemic diseases, including diabetes and chronic liver disease, show up as oral symptoms in the mouth, researchers say.
Several studies have found that people who have periodontal disease or other signs of oral infection are more likely to have heart attacks, heart disease or strokes. The increased likelihood of cardiovascular disease ranges from 20 percent to 280 percent.
Plaque and inflammation of the gums, which leads to gingivitis and periodontitis, also are associated with diabetes and cardiac disease.
And the diseases may manifest themselves unexpectedly in your mouth.
Jaundice may show up has as a yellow color in the gums.
Oral cancer may produce white lesions in the mouth, on the sides of the tongue, on the floor of the mouth and under the tongue.
Having fiery red gums that never seem to heal or lesions that don't go away, could be a sign of something serious, such as leukemia. A trained eye is needed to determine this.
Bulimia, which can cause eroded enamel, can lead to esophageal cancer.
Dry mouth could be a disease or just a medical side effect.
Even gums that bleed easily and loose teeth may mean bone loss, and possibly osteoporosis.
While researchers and doctors don't know the mechanism that triggers these things, they do believe in a possible association.
Doctors suggest brushing teeth twice daily and rinsing with an antiseptic mouthwash two times a day.
And it could mean good results aside from heart health.
Diabetes and poor oral care makes the disease harder to control.
There is even a theory that 20 percent of preterm babies are linked to oral infections in which bacteria may have traveled from the mouth to the placenta.