After extraction of tooth #30, the panoramic radiograph shows a very small radiopaque spot in the retromolar region. What is the lesion?

Foreign body (retained root tip) A small radiopaque spot in an extraction site is almost always a retained root tip or foreign body (bur fragment, amalgam, or restorative material). The management depends on size, proximity to vital structures, and symptoms; small, deep, asymptomatic root tips may be monitored.