Anatomical dimensions and variances of the foramen ovale in adult human skulls

Morphometry of the foramen ovale



Foramen ovale, Cranial base, Morphometry, Anatomy


Background/Aim: The foramen ovale (FO) is very important in neurosurgical approaches; however, studies and developments in the literature report that no definite consensus about the cannulation of the FO is available. Therefore, more morphometric information concerning the FO is needed in addition to the previously defined morphological and morphometric features. The aim of this study was to compare the features of the foramen ovale stated in the literature and to analyze the topographic relationship between the FO and the anatomical structures around it to determine its precise location.

Methods: The study included 70 sides from 35 dry skulls of unknown age and gender. Skulls with any deformity or pathology that would affect the measurements were not included in the study. All skulls were placed in the horizontal plane with the external occipital protuberance facing posteriorly, the piriform aperture facing anteriorly, and the skull base pointing upwards at a 90° angle after which it was photographed vertically with the length scale. A Nikon D5300 Digital Camera was used for the photography, and digital image processing software (Image J) was used for foramen ovale measurements. In addition, the shape of the foramen ovale was classified as oval, almond, D-shaped, slit-shaped, round, and irregular. SPSS 21.0 was used for the statistical analysis.

Results: The mean anteroposterior diameter length of the FO was 6.144 mm, and the transverse diameter length was 2.885 mm. When the distribution of the shape of the FO was examined, oval and almond shapes were most common shapes (34.29%). In addition, round (12.85%), D-shaped (10%), and slit-shaped (8.57%) were obtained. According to Pearson’s correlation analysis, the highest correlation was between the distance from the carotid canal to the foramen ovale and the shortest distance from the foramen ovale to the midline (FO-CC and the FO-ML, respectively; r = 0.427).

Conclusion: The morphology of the FO is important in terms of surgical and interventional approaches. In the literature, no significant differences between the right and left sides for the foramen ovale were found in contrast to our study. When the FO shape percentages were examined in most previous studies, it was seen that most of them were oval. In this study, the ratios of oval and almond shapes were the same. Morphometric measurements can give different results in every race due to the structure of the bones, which may vary according to the population. We think that presenting data on the Turkish population in this study will set an example for conducting future studies.


Download data is not yet available.


Zdilla MJ, Hatfield SA, McLean KA, Laslo JM, Cyrus LM, Lambert HW. Orientation of the Foramen Ovale: An Anatomic Study With Neurosurgical Considerations. J Craniofac Surg. 2016 Jan;27(1):234-7. doi: 10.1097/SCS.0000000000002332. PMID: 26703059; PMCID: PMC4706813. DOI:

Reymond J, Charuta A, Wysocki J. The morphology and morphometry of the foramina of the greater wing of the human sphenoid bone. Folia Morphol (Warsz). 2005 Aug;64(3):188-93. PMID: 16228954.

Natsis K, Piagkou M, Repousi E, Tegos T, Gkioka A, Loukas M. The size of the foramen ovale regarding to the presence and absence of the emissary sphenoidal foramen: is there any relationship between them? Folia Morphol (Warsz). 2018;77(1):90-8. doi: 10.5603/FM.a2017.0068. Epub 2017 Jul 13. PMID: 28703850. DOI:

Doğan Ü, Fazlıoğulları N, Uysal Z, Uysal İİ, Şeker M, Karabulut AK. Anatomical examination of the foramens of the middle cranial fossa. Int J Morphol. 2014 Mar;32(1):43-8. doi: 10.4067/S0717-95022014000100008. DOI:

Karthikeyan G, Sankaran PK, Raghunath G, Yuvaraj M, Arathala, R. Morphometric study of various foramina in the middle cranial fossa of the human skull. Indian J Clin Anat Physiol. 2017;4(4):574-8.

Mishra SJ, Sushobhana S, Singh S, Singh R, Gaharwar A. Morphometric and Topographic Study of Foramen Ovale in Indian Skulls. Malays J Med Biol Res. 2018 Dec;5(2):75-84. Doi: 10.18034/mjmbr.v5i2.455. DOI:

Patil J, Kumar N, K G MR, Ravindra S S, S N S, Nayak B S, et al. The foramen ovale morphometry of sphenoid bone in South Indian population. J Clin Diagn Res. 2013 Dec;7(12):2668-70. doi: 10.7860/JCDR/2013/7548.3727. Epub 2013 Dec 15. PMID: 24551606; PMCID: PMC3919287.

Zdilla MJ, Fijalkowski KM. The Shape of the Foramen Ovale: A Visualization Aid for Cannulation Procedures. J Craniofac Surg. 2017 Mar;28(2):548-51. doi: 10.1097/SCS.0000000000003325. PMID: 28027173. DOI:

Daimi SR, Siddiqui AU, Gill SS. Analysis of foramen ovale with special emphasis on pterygoalar bar and pterygoalar foramen. Folia Morphol (Warsz). 2011 Aug;70(3):149-53. PMID: 21866524.

Yanagi S. [Developmental studies on the foramen rotundum, foramen ovale and foramen spinosum of the human sphenoid bone]. Hokkaido Igaku Zasshi. 1987 May;62(3):485-96. Japanese. PMID: 3610040.

Ray B, Gupta N, Ghose S. Anatomic variations of foramen ovale. Kathmandu Univ Med J (KUMJ). 2005 Jan-Mar;3(1):64-8. PMID: 16401947.

Lang J, Maier R, Schafhauser O. Postnatal enlargement of the foramina rotundum, ovale et spinosum and their topographical changes. Anat. Anz. 1984;156(5):351-87.

Lang J, Maier R, Schafhauser O. Uber die postnatale Vergrösserung der Foramina rotundum, ovale et spinosum und deren Lageveränderungen [Postnatal enlargement of the foramina rotundum, ovale et spinosum and their topographical changes]. Anat Anz. 1984;156(5):351-87. German. PMID: 6486466.

Somesh MS, Sridevi HB, Prabhu LV, Swamy MS, Krishnamurthy A, Murlimanju BV, et al. A morphometric study of foramen ovale. Turk Neurosurg. 2011;21(3):378-83. doi: 10.5137/1019-5149.JTN.3927-10.2. PMID: 21845575. DOI:

Das S, Bhattacharjee S, Pal S. A morphometric study of foramen ovale. Indian J Clin Anat Physiol. 2019;6(3):359–62. Doi: 10.18231/j.ijcap.2019.078. DOI:

Ajrish George S, Thenmozhi MS. The morphometric study of occurrence and variations of foramen ovale. Drug Invent Today 2019;12(1):98–100.

Ravinthar TK. Morphometric Study of Size and Symmetry of Foramen Ovale in Dry Skulls. J Pharm Sci Res. 2015;7(10):830-3.

Srikantaiah VC, Shetty H. Anthropometric Evaluation of Foramen Ovale in Adult Dry Skulls of the Mysuru-based Population. J Morphol Sci. 2019;36(01):14-6. Doi: 10.1055/s-0039-1678754. DOI:

Sridhar S, Jayasree N, Chidambaram S, Vetrayan V. Morphometric Observations In Foramen Ovale (Fo) And Foramen Spinosum (Fs) Of Human Sphenoid Bones In Andhra Pradesh Populaiıons. J Head Neck Physicians Surg. 2014;3(1):18-28.

Burdan F, Umławska W, Dworzański W, Klepacz R, Szumiło J, Starosławska E, Drop A. Anatomical variances and dimensions of the superior orbital fissure and foramen ovale in adults. Folia Morphol (Warsz). 2011 Nov;70(4):263-71. PMID: 22117244.

Akçay E, Chatzioglu GN, Gayretli O, Gürses IA, Öztürk A. Morphometric measurements and morphology of foramen ovale in dry human skulls and its relations with neighboring osseous structures. Med Sci. 2021;10(3):1039-46. Doi: 10.5455/medscience.2021.04.149. DOI:

Özalp H, Beger O, Erdoğan O, Koç T, Kayan G, Hamzaoğlu V, et al. Morphometric Assessment of the Carotid Foramen for Lateral Surgical Approach. J Int Adv Otol. 2019 Aug;15(2):222-8. doi: 10.5152/iao.2019.6154. PMID: 31347511; PMCID: PMC6750789. DOI:

van Meurs JB, Boer CG, Lopez-Delgado L, Riancho JA. Role of Epigenomics in Bone and Cartilage Disease. J Bone Miner Res. 2019 Feb;34(2):215-30. doi: 10.1002/jbmr.3662. Epub 2019 Feb 4. PMID: 30715766. DOI:






Research Article

How to Cite

Açikgöz AK, Babacan S, Tuncel Çini N, Bozkir MG. Anatomical dimensions and variances of the foramen ovale in adult human skulls: Morphometry of the foramen ovale. J Surg Med [Internet]. 2022 Sep. 30 [cited 2024 Feb. 28];6(10):839-43. Available from: