Brain abscesses caused by oral infection

Brain abscesses are rare but can be life-threatening infections. Recent pro gress in microbiological classification and identification has indicated th at they are sometimes caused by oral infection and dental treatment. It has been postulated that oral microorganisms may enter the cranium by several pathways: 1) by direct extension, 2) by hematogenous spread, 3) by local ly mphatics, and 4) indirectly, by extraoral odontogenic infection. In the dir ect extension, oral infections spread along the fascial planes. Hematogenou s spreading occurs along the facial, angular, ophthalmic, or other veins wh ich lack valves, through the cavernous sinus and into the cranium. Another hematogenous pathway is through the general circulation. Oral bacteria may cause systemic infections, e.g., endocarditis, and then indirectly initiate brain abscess. Microbiota., complications, and the prevention and manageme nt of odontogenic brain abscesses are also discussed in this review.