For a child requiring interproximal caries detection and radiographic confirmation of a suspected odontogenic infection near the orbit, which imaging modality gives the most useful three-dimensional information about the extent of spread?

Correct answer: B. Cone-beam computed tomography

• A. An occlusal radiograph is useful for sialoliths, palatal expansion, and localization by the tube-shift technique, but not for assessing fascial space infection.
• B. CORRECT. When infection has spread into the fascial spaces and the concern is the EXTENT of that spread in three dimensions, CBCT (or medical CT with contrast, which better shows soft tissue and abscess collections) provides the anatomic information needed. Two-dimensional imaging cannot delineate the spaces involved or identify a drainable collection.
• C. A panoramic radiograph gives a broad screening view of both jaws and is useful for identifying the offending tooth, but it is a two-dimensional image that cannot map soft tissue spread.
• D. Bitewings show only crowns and crestal bone — they identify the carious source but say nothing about spread.

Note: For a spreading infection near the orbit, the clinical priority is urgent referral and IV antibiotics — imaging should not delay treatment.