Cardiac Tamponade Due to Actinomyces odontolyticus Originating From a Dentigerous Cyst

This report describes a rare case of pericardial effusion owing to Actinomyces odontolyticus in a 52-year-old woman that originated from a dentigerous cyst, which developed on the distal aspect of a lower left third molar. The cyst had remained asymptomatic for a long period, with no specific functional complications. This is the first case report of a patient with acute pericarditis in which the same strain of A odontolyticus was detected in an asymptomatic dentigerous cyst and in the pericardial fluid.