The foramen rotundum is a circular bony opening in the sphenoid bone at the skull base.
Anatomy
The maxillary nerve passes through the foramen rotundum as the second branch of the trigeminal nerve.
The diameter of the foramen rotundum is approximately 3 mm in an adult1:
| Foramen rotundum | Mean diameter (mm) | Standard deviation |
|---|---|---|
| Left foramen rotundum | 3,01 mm | 0,43 mm |
| Right foramen rotundum | 3,00 mm | 0,43 mm |
During development, the foramen rotundum can be observed in the fetus from the fourth month of development onward as an oval structure, which assumes a round shape at birth2.
Anatomical variants
Individual cases have been described in the literature in which the foramen rotundum was duplicated3.
Figure
References
Sepahdari, A. R., & Mong, S. (2012). Skull base CT: normative values for size and symmetry of the facial nerve canal, foramen ovale, pterygoid canal, and foramen rotundum. Surgical and Radiologic Anatomy, 35(1), 19–24. ↩ ↩
Yanagi S. Developmental studies on the foramen rotundum, foramen ovale and foramen spinosum of the human sphenoid bone Hokkaido Igaku Zasshi The Hokkaido Journal of Medical Science. 1987 May;62(3):485-496. ↩ ↩
Syed, A., et al. "Duplication of the foramen rotundum: A rare case report." Morphologie 107.356 (2023): 138-141. ↩ ↩