3-27. RADIOLUCENT LANDMARKS ON MANDIBULAR RADIOGRAPHS
a. Mandibular Foramen. The mandibular foramen is seen on extraoral
mandibular films as a dark area near the middle of the mandibular ramus.
b. Mandibular Canal. The mandibular canal (see figure 3-28) appears as a
dark band with radiopaque borders running downward and forward from the mandibular
foramen in the ramus to the region of the bicuspid teeth in the body of the mandible. It
may be seen below the roots of the posterior teeth.
Figure 3-28. Mandibular canal.
c. Mental Foramen. The mental foramen (see figure 3-29) is seen as a dark
area below and between the bicuspids. Since it is not contiguous with either bicuspid,
its relationship to these teeth appears different on radiographs made at different
Figure 3-29. Mental foramen.