Migration of a Separated Endodontic File Into the Mandibular Canal: An 8-Year Follow-up Case Report

Separated endodontic instruments in mandibular molars may migrate into the mandibular canal, potentially causing neurological complications. The management of asymptomatic cases remains controversial. This case report presents the long-term conservative management of a separated stainless steel file that migrated into the mandibular canal. A 47-year-old male patient with chronic myeloid leukemia presented with a separated endodontic file that had migrated from the distal root of his mandibular right second molar into the mandibular canal over a 7-year period. Clinical examination, panoramic radiography, and cone-beam computed tomography were performed. Quantitative sensory testing using Semmes-Weinstein monofilament testing and psychological assessment were conducted. Conservative management with periodic observation was selected due to the patient's asymptomatic status. Cone-beam computed tomography revealed the separated file extending 1.43 mm into a mandibular canal with a diameter of 2.54 mm. Despite radiographic evidence of neural canal involvement, the patient remained asymptomatic throughout the 7-year observation period. Semmes-Weinstein monofilament testing detected minimal tactile sensitivity differences (0.1 g vs 0.55 g on the contralateral side), but no clinically significant neurological symptoms developed. Follow-up radiography at 8 years showed continued migration toward the inferior mandibular border without symptom development. Long-term migration of separated stainless steel endodontic files into the mandibular canal may remain asymptomatic. Adequate anatomical space within the mandibular canal, biocompatible properties of stainless steel, and patient-specific factors affecting sensory perception may contribute to the benign clinical course. Conservative management based on clinical symptomatology rather than radiographic findings alone appears appropriate in select asymptomatic cases, with regular monitoring recommended to detect potential delayed complications.