A 5-year-old girl fell 3 days ago and lost a primary tooth. Her guardian reports a bump appearing on the gingiva in the area. What is this most likely?

Correct answer: B. Sinus tract (parulis)

• A. Incorrect. Gingival cysts of the newborn (Bohn's nodules) occur in neonates, not 5-year-olds after trauma.
• B. CORRECT. A sinus tract (parulis) is the most likely diagnosis. After traumatic loss of a primary tooth, infection of the alveolus or injury to the permanent tooth bud can lead to a localized abscess that drains through the gingiva as a sinus tract. The 3-day post-trauma timeline and location are classic for this presentation.
• C. Incorrect. Epulis fissuratum results from chronic denture flange irritation — not applicable in a 5-year-old post-trauma case.
• D. Incorrect. Erythema migrans (geographic tongue) is a benign migratory mucosal condition unrelated to tooth trauma.