• Svetlana Jovevska Faculty of Medical Sciences, Goce Delcev, University, Stip
  • Sanja Baldzieva Faculty of Medical Sciences, Goce Delcev, University, Stip
Keywords: Occipital bone, great occipital opening, variations, form, oval, circular, irregular


Nowadays, in the diagnosis of the extensive endocranial processes, major significance is attributed to the secondary changes in the skull that appear also in the X-Rays. Despite some successes in the development of the X-ray anatomy of the skull and in the study of secondary changes, there are major difficulties in reading the X-rays. This is explained by the fact that the variability in the construction of the various parts of the skull is more frequent, especially at its base and in the area of the great occipital opening.
In the literature it can hardly be found how the variations in the shape of the great occipital opening are described and peculiarities in the construction of its rear end. In healthy persons, the semi-axial X-rays of the great occipital opening have an oval shape, a clear and smooth back end, surrounded by a solid bone cylinder that passes toward the middle in the vertically set ridge of the occipital bone.
When tumors in the posterior cranial fossa are described, many authors note changes in the great occipital opening in the form of osteoporosis, atrophy, and slinging the skull at the posterior end of the opening, with local cleavers and leveling of the corresponding part of the occipital bone, known as the Bapcin symptom.
The anatomical variation of the form of the foramen occipital magnum was axsamined on 80 calvarials. With detail analysis we identified three normal variations of the form of the foramen occipital magnum : the oval (48 cases), the round (21 cases) and the anomalous form (11 cases). Also the dorsal end and osseous configuration of the occipital bone was examined.
The importance of this study is it’s prognostic and diagnostic application in the clinical and roentgengratic research.
Greatest difficulties arise in the malignant brainstem process, especially when the invasive process goes to the middle of the back of the great occipital opening.
Knowledge of foramen occipital magnum variations is important for surgeons in pereforming many procedures and it may help to avoid clinical coplications, especially, during radiological examination.


Iqbal S1, Robert AP2, Mathew D2. Computed tomographic study of posterior cranial fossa, foramen magnum, and its surgical implications in Chiari malformations.Asian J Neurosurg. 2017 Jul-Sep;12(3):428-435.

Kanodia G1, Parihar V, Yadav YR, Bhatele PR, Sharma D. Morphometric analysis of posterior fossa and foramen magnum.J Neurosci Rural Pract. 2012 Sep;3(3):261-6.

Muthukumar N1, Swaminathan R, Venkatesh G, Bhanumathy SP A morphometric analysis of the foramen magnum region as it relates to the transcondylar approach.Acta Neurochir (Wien). 2005 Aug;147(8):889-95. Epub 2005 Jun 9.

Raghavendra Babu YP1, Kanchan T, Attiku Y, Dixit PN, Kotian MS. Sex estimation from foramen magnum dimensions in an Indian population. J Forensic Leg Med. 2012 Apr;19(3):162-7. doi: 10.1016/j.jflm.2011.12.019.

Dowd GC1, Zeiller S, Awasthi D. Far lateral transcondylar approach: dimensional anatomy. Neurosurgery. 1999 Jul;45(1):95-9

How to Cite
Jovevska, S., & Baldzieva, S. (2017). VARIATION OF THE FORM OF THE FORAMEN OCCIPITALE MAGNUM. Knowledge International Journal, 19(4), 1521 - 1524. Retrieved from