According to Health News:

"Stroke - A study of over 800 stroke victims indicates that advanced gum disease can increase the risk of stroke by over 50% in adults aged 25-54.

Diabetes - It's a two-way street. Type II diabetics are 3 times more likely to develop gum disease (20 times more likely if they smoke). Recent studies also confirm that Periodontal (gum) disease disrupts glycemic control. So for Type II diabetics, not only are they at risk for gum disease, bgum disease also aggravates their diabetes.

Heart Disease - Many studies show a link between gum disease and heart disease. One study indicates that the risk of fatal heart disease is stwice as high for individuals with severe gum disease.

Spontaneous preterm births - The latest evidence indicates that pregnant women with severe gum disease are seven times more likely to have a premature baby. Scientists believe that the infection releases toxins that reach the placenta and disrupt fetal development. The oral infection also leads to accelerated production of hormones that trigger premature delivery."