
There are references in many historical texts about the correlation between oral health (gum diseases) and general health. Some texts even claimed that the extraction of problematic teeth solved a wide range of systemic problems.
The theory of focal infection gained prominence in the late 1800s, thanks to some pioneering work by William Hunter and his colleagues. The favoured theory at that time was Oral Sepsis - which had a considerable influence on dentistry at that time. The mid-20th century a moving away from this, and in 1955, with the publication of strong papers in the Journal of American Medical Association the theory fell into disrepute.
The focal infection theory has seen resurgence in the past two decades, courtesy a few landmark studies, notably by Matilla K and his co-workers. With well-documented evidence of the effect of systemic diseases on oral health, these studies established that dental health affects systemic health and disease status. Periodontal Medicine was born.
Periodontal medicine suggests the existence of a two-way relationship between periodontal (and oral) health (and disease) and the systemic status of a person. Apart from the more customarily understood influence of systemic disease on periodontal status, it puts forward the possibility that periodontal status of an individual may be a significant influence on his/her systemic health, either by initiating or, most possibly, altering the natural course of a disease. Also, the definition includes new diagnostic and treatment strategies that recognize the relationship between periodontal disease and systemic disease.