Panoramic X-rays illustrating the vertical linear measurements D1 to D7 on left and right sides (‘). D1: vertical distance from the inferior border of the mental foramen to the inferior limit of the base of mandible; D2: vertical distance from the superior border of the mental foramen to the superior limit of the highest alveolar ridge; D3: vertical distance from the inferior border of the mandibular canal to the inferior border of the base of mandible, on a vertical line through the mandibular ramus anterior border; D4: vertical distance from the superior border of the mandibular canal to the inferior limit of the oblique line, on a vertical line through the mandibular ramus anterior border; D5: vertical distance from the lowest point of the mandibular canal to the inferior limit of the base of mandible; D6: vertical distance from the lowest point of the mandibular notch to the mandibular foramen; D7: vertical distance from the lowest point of the mandibular notch to the inferior border of the mandibular ramus. The mean values were calculated for distances D1-D7, considering sex, side, and age group.