Several studies have reported the prevalence of pathology associated with retained third molar teeth. Although most oral surgeons have encountered many patients with infection and lytic lesions associated with retained third molars, assessment of the frequency of abnormality around these teeth has previously been hampered by the lack of well-designed studies to investigate a subject so important to oral and maxillofacial surgeons. This article reviews what is known—and what isn’t known—about pathologic conditions associated with both symptomatic and asymptomatic third molar teeth.