Due to the low incidence rate of oral cancer, studies have not been able to conduct quality studies to prove the association between the two, however future larger studies may aid in the identification of individuals at a higher risk.Systemic implications
Periodontal disease (PD) can be described as an inflammatory condition affecting the supporting structures of the teeth. Studies have shown that PD is associated with higher levels of systemic inflammatory markers such as Interleukin-6 (IL-6), C-Reactive Protein (CRP) and Tumor Necrosis Factor (TNF). To compare, elevated levels of these inflammatory markers are also associated with cardiovascular disease and cerebrovascular events such as ischemic strokes.The presence of a wide spectrum inflammatory oral diseases can increase the risk of an episode of stroke in an acute or chronic phase. Inflammatory markers, CRP, IL-6 are known risk factors of stroke. Both inflammatory markers are also biomarkers of PD and found to be an increased level after daily activities, such as mastication or toothbrushing, are performed. Bacteria from the periodontal pockets will enter the bloodstream during these activities and the current literature suggests that this may be a possible triggering of the aggravation of the stroke process.Other mechanisms have been suggested, PD is a known chronic infection. It can aid in the promotion of atherosclerosis by the deposition of cholesterol, cholesterol esters and calcium within the subendothelial layer of vessel walls. Atherosclerotic plaque that is unstable may rupture and release debris and thrombi that may travel to different parts of the circulatory system causing embolization and therefore, an ischemic stroke.
It is often possible to manage these symptoms with specific behavioral techniques. Another evolutionary psychology view is that some forms of fainting are non-verbal signals that developed in response to increased inter-group aggression during the paleolithic. A non-combatant who has fainted signals that she or he is not a threat. This would explain the association between fainting and stimuli such as bloodletting and injuries seen in blood-injection-injury type phobias such as needle phobia as well as the gender differences.Much of this pathway was discovered in animal experiments by Bezold (Vienna) in the 1860s. In animals, it may represent a defence mechanism when confronted by danger ("playing possum"). Situational syncope
Syncope may be caused by specific behaviors including coughing, urination, defecation, vomiting, swallowing (deglutition), and following exercise. Manisty et al. note: "Deglutition syncope is characterised by loss of consciousness on swallowing; it has been associated not only with ingestion of solid food, but also with carbonated and ice-cold beverages, and even belching." Fainting can occur in "cough syncope" following severe fits of coughing, such as that associated with pertussis or "whooping cough." Neurally mediated syncope may also occur when an area in the neck known as the carotid sinus is pressed. A normal response to carotid sinus massage is reduction in blood pressure and slowing of the heart rate. Especially in people with hypersensitive carotid sinus syndrome this response can cause syncope or presyncope.