Injury of the inferior alveolar nerve after overfilling of the root canal with endodontic cement: a case report

The inferior alveolar nerve (IAN) contains mainly sensory fibers. Within the mandibular canal, the IAN runs forward in company of the inferior alveolar artery, and together they are called the inferior alveolar neurovascular bundle. Disturbances of the IAN and mental nerve will predominantly give sensitivity symptoms in the soft tissue of the lower lip and chin. We present a case report of endodontic overfilling involving the mandibular canal. A 52-year-old woman was seen in our outpatient clinic for pain and numbness in the left lower lip and chin, which developed following an endodontic treatment for her mandibular left second premolar. The panoramic radiograph showed radiopaque material in the inferior alveolar canal region, with an extension from the left canine to the second premolar. This case report shows an unusual complication of mandibular second premolar root canal overfilling. The patient underwent treatment with corticosteroids, and after 2 months, the clinical examination revealed an improved clinical situation with a disappearance of the hypoesthesia but with a persistence of the pain. After 4 months, the pain had almost entirely disappeared. In conclusion, even if in our case no surgical treatment was used and although spontaneous resorption has been described for some materials, early surgical exploration with removal of the material and decompression of the IAN is suggested, irrespective of the material used, because the severity of nerve damage can increase with the duration of the injury.