<prompt> The radiopaque structure shown in the box is most likely:Lingual foramenGenial tuberclePCDNone of the above  <response>: The genial tubercles also called the mental spine are located on the lingual surface of the mandible slightly above the inferior border and in the midline. They are bony protuberances, more or less spine-shaped, that often are divided into a right and left prominence and a superior and inferior prominence. They attach the genioglossus muscles at the superior tubercles and the geniohyoid muscles at the inferior tubercles to the mandible. They are well visualized on mandibular occlusal radiographs as one or more small projections. Their appearance on periapical radiographs of the mandibular incisor region is variable; often they appear as a radiopaque mass 3 to 4 mm in diameter in the midline below the incisor roots. Lingual foramen is a radiolucent structure seen in the midline.Ref: White and Pharoah, pg-144,145 