What is the most likely diagnosis suggested by this specific pocketing pattern?
Case
A previously root-canal-treated premolar presents with a narrow, deep periodontal pocket isolated to a single line angle, and a sinus tract near the mid-root level. The rest of the periodontium is healthy.
Explanation
A narrow, deep, isolated probing defect at a single line angle — as opposed to the broad pattern seen in periodontitis — combined with a mid-root sinus tract is a classic presentation of a vertical root fracture. This is frequently misread as a failing root canal, which delays the correct diagnosis and management.
Clinical Pearl
The isolated narrow pocket is often a more reliable sign of a VRF than the radiograph, which can look unremarkable until the fracture has progressed significantly.
Reference: Standard endodontic diagnosis protocol — VRF