Mandibular foramen

The mandibular foramen is an opening on the internal surface of the ramus of the mandible for divisions of the mandibular nerve and blood vessels to pass through.

Mandibular foramen
The mandibular foramen sits in the ramus of the mandible
Mandible viewed from the inner side of the mandible, showing the mandibular foramen at left.
Details
Identifiers
Latinforamen mandibulae
TA98A02.1.15.028
TA2865
FMA53172
Anatomical terms of bone

Structure

The mandibular foramen is an opening on the internal surface of the ramus of the mandible for divisions of the mandibular nerve and blood vessels to pass through.

Variation

There are two distinct anatomies to its rim.

  • In the common form the rim is “V” shaped, with a groove separating the anterior and posterior parts.
  • In the horizontal-oval form there is no groove, and the rim is horizontally oriented and oval in shape, the anterior and posterior parts connected.

Rarely, a bifid inferior alveolar nerve may be present, in which case a second mandibular foramen, more inferiorly placed, exists and can be detected by noting a doubled mandibular canal on a radiograph.[1]

Function

The mandibular nerve is one of three branches of the trigeminal nerve, and the only one having motor innervation.

One branch of it, the inferior alveolar nerve as well as the inferior alveolar artery enter the foramen traveling through the body in the mandibular canal and exit at the mental foramen on the anterior mandible at which point the nerve is known as the mental nerve.

These nerves provide sensory innervation to the lower teeth, as well as the lower lip and some skin on the lower face.

Additional images
  • View from behind of the mandibular foramina (red).

References
  1. Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, page 59
  • cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (V)
  • Nicholson, Michael L. (1985). "A study of the position of the mandibular foramen in the adult human mandible". The Anatomical Record. 212 (1): 110–2. doi:10.1002/ar.1092120116. PMID 4073538.
  • Hetson, George; Share, Jack; Frommer, Jack; Kronman, Joseph H. (1988). "Statistical evaluation of the position of the mandibular foramen". Oral Surgery, Oral Medicine, Oral Pathology. 65 (1): 32–4. doi:10.1016/0030-4220(88)90187-9. PMID 3422395.
  • Smith, Fred H. (1978). "Evolutionary significance of the mandibular foramen area in neandertals". American Journal of Physical Anthropology. 48 (4): 523–31. doi:10.1002/ajpa.1330480412. PMID 96699.
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