[An update on focal infection of oral origin].

Focal infection of oral origin means that an oral infectious focus may have widespread effects. This concept remains controversial since it is difficult to prove the oral origin of germs responsible for an extra-oral infection. Experiments on animal models and clinical studies suggested several physiopathological mechanisms: bacteremia, toxinic and immunological mechanisms. Various operations induce the passage of bacterial flora (transcytosis) and its toxins into the bloodstream: oral care, chewing, or tooth brushing. Bacteremia is worsened by poor oral hygiene or an infection. The germs are usually destroyed by the host's reticuloendothelial system in a few minutes, but the presence of a valvular disease or a weak immune system favors focal infection. Besides infectious endocarditis, this may concern cardiovascular diseases, lung infections, prematurity and hypotrophy, diabetes, prosthetic infections, cerebral abscesses, etc. This update is based on literature review, selected according to its high level of scientific proof, as well as on a selected choice of consensus conferences. The current recommendation is to limit antibiotic prophylaxis to the high bacteremia risk procedures and to patients highly at risk of developing a focal infection.