Definition: A foramen seen near the apex of the mandibular second premolar. It may be projected as far mesially as the first premolar and distally as the first molar. To determine if a radiolucent area seen at the apex of the second premolar is pathosis associated with the tooth or normal anatomy (mental foramen) you need to evaluate the periodontal ligament space and lamina dura. If it is intact around the apex, the radiolucent area is most likely normal anatomy (mental foramen). If it is not intact around the apex and continuous with the radiolucent area, it is most likely pathosis of odontogenic origin.
Radiographic Features:
Location: Apical to the mandibular second premolar.
Edge: Well-defined.
Shape: Round to ovoid.
Internal: Radiolucent.
Other: None.
Number: Single (per side :))
(click to enlarge)
Mental foramen
Round/ovoid radiolucent entity mesial to second premolar apex (yellow circle)
Mental foramen – periapical radiographs
Mental foramen – pantomograph
