The Impacted Mandibular Second Molar with Its Roots Perforated by the Inferior Alveolar Nerve

This case report demonstrates an unusual impacted mandibular second molar perforated by the inferior alveolar canal. A 23-year-old man with an impaction of the right mandibular second molar visited the department of orthodontics. The right mandibular second molar was vertically impacted with multiple compound odontomas, and the roots were perforated by the inferior alveolar canal, making hard to move it orthodontically. Therefore, the impacted mandibular second molar was extracted under general anesthesia instead of orthodontic traction. After orthodontic treatment and prosthetic rehabilitation, favorable occlusion was achieved without any sign of inferior alveolar nerve injury. On the cone beam computed tomography images, the constricted inferior alveolar canal which was passing through the impacted roots expanded after extraction of the tooth.