The mental foramen and anterior loop of the mandibular canal are important landmarks for mandibular surgical procedures. The purpose of this study was to analyze the shape and position of the mental foramen and anterior loop of the mandibular canal on the computed tomography (CT) images, and apply the results clinically. CT images of 96 patients (33 male, 36 female, age range 17~43 years, mean $24.6{pm}4.99$ years) were enrolled. The horizontal and vertical position of the mental foramen, as well as the distance from the root apices were measured. The distance of the anterior loop of the mandibular canal to the root apices, and the buccal angle were measured. The mental foramen was found mostly below the second premolar observed in 81 cases (46.0%), between the first and second premolars in 67 cases (38.0%), and between the second premolar and first molar in 19 cases (10.2%). The mean distance between the mental foramen and the lower border of the mandible was $12.20{pm}1.77$ mm, the mean distance between the mental foramen and root apex was $5.16{pm}0.98$ mm. The mean distance of the anterior loop of the mandibular canal was $5.80{pm}2.00$ mm. The buccal angle measured at $47.7{pm}9.07^{circ}$. The distance between the root apex and mental foramen measured as $5.16{pm}0.98$ mm on panoramic radiography, and $6.2{pm}3.07$ mm on CT. The mean distance between the mental foramen and mandibular canal was $5.39{pm}1.62$ mm. When performing surgical procedures such as installing dental implants, it is important to minimize surgical trauma, especially the risk of damage to the mental nerve. To optimize the surgical outcome, a careful assessment of the shape and position of the mental foramen and the anterior loop of the mandibular canal must be made. CT images are useful for finding such anatomic structures.