A 26-year-old man was suffering from pericoronitis of his mandibular third molars. To determine the position of the mandibular canal in relation to the roots of the third molars, a panoramic radiograph was made. The radiograph revealed at the right side a bifid mandibular canal and the upper part of the canal seemed to be related to the third molar. Additionally, a cone beam CT was made, which revealed a bifid mandibular canal at the left side and a trifid mandibular canal at the right side. Anatomical anomalies of the mandibular canal may have clinical implications, such as an increased risk of injury to the inferior alveolar nerve in case of removing a mandibular third molar and inadequate local anesthetics.