Mental foramen is?

• A. The posterior opening of the inferior alveolar canal
• B. A foramen in the maxillary sinus
• C. The anterior opening of the inferior alveolar canal
• D. An opening for the mental nerve on the lingual surface

Answer: (C)

The mental foramen is the anterior opening of the inferior alveolar canal on the external surface of the mandible through which the mental nerve exits to supply the chin and lower lip. The nerve travels inside the canal from the posterior opening at the mandibular foramen (on the inner aspect of the ramus) toward the front. A foramen in the maxillary sinus is a different structure, and the mental foramen is not on the lingual surface—it’s on the facial/anteromedial surface near the premolars.