Distal Split with Missed Canal and Separated File in the MB Canal

It is not always the most obvious finding on a radiograph that explains the patient’s persistent symptoms or treatment failure. This case highlights the importance of comprehensive history taking and clinical suspicion in achieving accurate diagnosis. A patient presented after undergoing root canal treatment elsewhere, where a file had fractured in the mesiobuccal canal. The previous dentist reassured the patient that the separated file would not compromise the outcome, as it had occurred after cleaning and shaping. However, the patient returned with the same pain, and the case was subsequently referred. Upon careful evaluation and detailed history taking, it became clear that the broken file might not be the primary source of the symptoms. Clinical exploration revealed a deep distal…