A. Preoperative radiograph of Case 1 showing Vertucci type V root canal configuration; B. Working radiograph: two instruments are inserted in the vestibular and lingual canals. The site of bifurcation of the canal is clearly seen; C. Postoperative radiograph: the main and accessory root canals have been successfully filled. D. Diagnostic radiograph of the opposite mandibular segment: Vertucci type V root canal anatomy is found in tooth #44 as well.