A radiolucent lesion is noted between teeth #13 and #14 on a periapical radiograph. All of the following should be included in the differential diagnosis EXCEPT one. Which is the EXCEPTION?

Correct answer: C. Ameloblastoma

• A. Lateral periodontal cyst is the MOST LIKELY diagnosis for a well-defined radiolucency between the roots of vital teeth in the premolar region. It represents a developmental odontogenic cyst.
• B. Traumatic bone cyst (simple bone cyst) typically appears as a radiolucency with scalloped margins between roots in younger patients — it is a valid differential for this location.
• C. CORRECT. Ameloblastoma most commonly occurs in the POSTERIOR MANDIBLE (not maxilla), and while maxillary ameloblastoma exists, a lateral interproximal radiolucency between maxillary premolars is more consistent with a lateral periodontal cyst, OKC, or traumatic bone cyst. Ameloblastoma is the LEAST likely in this specific location and presentation, making it the exception.
• D. OKC can occur anywhere in the jaws, including the premolar area, and should always be in the differential for jaw radiolucencies.