OPG showing metric measurements of MF from landmarks.Point F: The reference point of the mandibular foramen. Line AF – distance from the reference point of MF to the anterior border of the ramus. PF – Distance between the reference point of MF to the posterior border of the ramus. NF – Distance reference point of MF to mandibular notch. LF – Distance from the reference point of MF to the lower border of the mandible.