DAY 2 — CASE 13: The radiograph shows a periapical radiolucency around the root of the tooth with a chronic fistula (sinus tract). What is the radiographic lesion?

Correct answer: A. Periapical granuloma

• A. A CHRONIC PERIAPICAL GRANULOMA is the most common periapical radiolucent lesion (accounts for ~50% of all periapical lesions). It is characterized by a chronic, low-grade inflammatory response at the periapex of a non-vital tooth. The sinus tract drains the granuloma, providing chronic decompression. Radiographically: well-defined periapical radiolucency.
• B. A periodontal abscess is associated with the lateral aspect of the root and periodontal pocket — not typically periapical.
• C. A periapical ABSCESS has an ACUTE presentation (severe pain, swelling, fever) — not consistent with a chronic draining sinus tract.
• D. A radicular cyst can be radiographically indistinguishable from a granuloma but is less common; definitive distinction requires biopsy. The most COMMON diagnosis for a chronic periapical RL is granuloma.