Bacterial respiratory infections are thought to be acquired through aspiration (or inhaling) of fine droplets from the mouth and throat into the lungs. These droplets contain germs that can breed and multiply within the lungs to cause damage. Recent research suggests that bacteria found in the throat as well as bacteria found in the mouth can be drawn into the lower respiratory tract causing infections or worsening conditions. People with respiratory diseases, such as chronic obstructive pulmonary disease, typically suffer from reduced protective systems, making it difficult to eliminate bacteria from the lungs.
Scientist have found that bacteria that grow in the oral cavity can be aspirated into the lung to cause respiratory diseases such as pneumonia, especially in the people with periodontal disease. This discovery leads researchers to believe that these respiratory bacteria can travel from the oral cavity into the lungs to cause infection.
Chronic obstructive pulmonary diseases (COPD) cause persistent obstruction of the airways. The main cause of this disease is thought to be long-term smoking. Chemicals from smoke or air pollution irritate the airways to cause obstruction. Further damage to the tissue and working function of the lungs can be prevented, but already damaged tissue cannot be restored -untreated or undetected COPD can result in irreversible damage. Scientists believe that through the aspiration process, bacteria can cause frequent bouts of infection in patients with COPD. Studies are now in progress to learn to what extent oral hygiene and periodontal disease may be associated with more frequent bouts of respiratory disease and COPD patients, likely because of the high levels of oral bacteria and inflammatrion present in their gums as the result of poor oral hygiene and periodontal disease.
According to the National Center for Health Statistics, millions of Americans suffer from respiratory diseases: 4.2 million cases of pneumonia are reported each year, and COPD including chronic bronchitis and emphysema, are responsible for over 160,000 deaths, 10 million office visists and 2 million hospitalizations annually.