Welcome to International Journal of Anatomy and Research

Type of Article: Original Research

Year: 2016 | Volume 4 | Issue 3 | Page No. 2593-2599

Date of Publication: 31-07-2016

DOI: http://dx.doi.org/10.16965/ijar.2016.283

MORPHOMETRY AND SEXUAL DIMORPHISM IN FORAMEN MAGNUM: A STUDY OF HUMAN SKULL BONES

Vinutha. S.P *¹, Shubha. R ².

^*1 Assistant Professor, Department of Anatomy, JSS Medical College, Mysuru, Karnataka, India.

² Professor, Department of Anatomy, Kempegowda Institiute of Medical Sciences, Bengaluru, Karnataka, India.

Address: Dr Vinutha. S.P, Assistant Professor, Department of Anatomy, JSS Medical College, Mysuru – 570015, Karnataka, India. Mobile No: +919481155140, +919916372652
E-Mail: drvinutha.sp@gmail.com

ABSTRACT

Background and Objectives: The foramen magnum is a fundamental component in the interaction of bony, ligamentous and muscular structures composing the craniovertebral junction. The measurements of the foramen magnum have a crucial importance in surgical resection and thereby reaching the lower clivus and premedullary region in transcondylar approach. The objectives of the present study are to find out the shape and dimensions of foramen magnum in human skull bones.

Materials and Methods: The study sample comprised of 200 skull bones (100 males and 100 females) of south Indian origin. Measurements were taken using sliding vernier calipers. The parameters were noted meticulously and the statistical analysis for sex comparison was made by student’s t-test and was considered significant whenever p≤0.05.
Results: The Foramen magnums were classified into 8 types based on shape. Commonest being oval and pentagonal was the least common type.  The mean APD of FM in male and female skull bones were found to be 33.37 mm ± 2.33 and 29.72 mm ± 1.89 respectively. The mean TD of FM in male and female skull bones were found to be 27.40 mm ± 2.44 and 24.73 mm ± 2.05 respectively. The mean circumference of FM in male and female skull bones was found to be 102.58 mm ± 4.68 and 92.65 mm ± 4.37 respectively.  The area of the FM was calculated using three different formulas. The mean area 1 of FM in male and female skull bones was found to be 718.41 mm² ± 83.75 and 577.52 mm² ± 64.36 respectively. The mean area 2 of FM in male and female skull bones was found to be 727.50 mm² ± 83.12 and 583.71 mm² ± 63.58 respectively. The mean area 3 of FM in male and female skull bones was found to be 838.77 mm² ± 75.94 and 684.36 mm² ± 64.10 respectively. All parameters were significantly greater in males than in females (P<0.001).
Conclusion: The data obtained may be useful to the neurosurgeon in analyzing the morphological anatomy of the craniovertebral junction. The findings are of particular interest in anthropology, anatomy, forensic medicine and other medical fields.
KEY WORDS: Foramen magnum, Sexual dimorphism, Shape, Anteroposterior Diameter, Transverse Diameter.

REFERENCES

1. Standring S, Borely NR, Collins P, Crossman AR, Gatzoulis MA, Healy JC, et al. Gray’s Anatomy : The Anatomical Basis of Clinical Practice. 40^th Ed, London: Elsevier Ltd; 2008. P. 415,420,424,711.
2. Murshed KA, Cicekcibasi AE, and Tuncer I. Morphometric Evaluation of the Foramen Magnum Variations in its Shape: A Study on Computerized Tomographic Images of Normal Adults. Turkish Journal of Medical Sciences.2003; 33(1):301-306.
3. Manoel C, Prado FB, Caria PHF, Groppo FC. Morphometric analysis of the foramen magnum in human skills of Brazilian individuals: its relation to gender. Brazilian Journal of Morphologic sciences. 2009; 26(2): 104-108.
4. Galdames ICS, Russo PP, Matamala DAZ, Smith RL. Sexual Dimorphism in the Foramen Magnum Dimensions. International Journal of Morphology. 2009; 27(1): 21-23.
5. Macaluso PJ. Metric sex determination from the basal region of the occipital bone in a documented French sample. Bull. Mem. Soc. Anthropol. Paris. 2011; 23:19-26.
6. Govsa F, Ozer MA, Celik S, Ozmutaf NM. Three-Dimensional Anatomic Landmarks of the Foramen Magnum for the Craniovertebral Junction. The journal of Craniofacial Surgery. 2011; 22(3):1073-1076.
7. Radhakrishna SK, Shivarama CH, Ramakrishna A, Bhagya B. Morphometric Analysis of Foramen Magnum for Sex Determination in South Indian Population. Nitte University Journal of Health Science. 2012; 2(1):20-22.
8. Chethan BV, Prakash KG, Murlimanju BV, Prabhu LV, Saralaya VV, Krishnamurthy A, et al. Morphological Analysis and Morphometry of the Foramen Magnum: An Anatomical Investigation. Turkish neurosurgery. 2011; 22(4):416-419.
9. Muthukumar N, Swaminathan R, Venkatesh G, Bhanumathy SP. A morphometric analysis of the transcondylar approach. Acta Neurochir (wien). 2005; 147:889-895.
10. Prakash BS, Latha PK, Menda JL, Ramesh BR. A tubercle at the anterior margin of foramen magnum. International Journal of Anatomical Variations. 2011; 4:118-119.
11. Tubbs RS, Griessenauer CJ, Loukas M, Shoja MM, Cohen-Gadol AA. Morphometric Analysis of the Foramen Magnum: An Anatomic Study. Neurosurgery. 2010; 66(2):385-388.
12. Gapert R, Black S, Last J. Sex determination from the foramen magnum: discriminant function analysis in an eighteenth and nineteenth century British sample. International Journal of Legal Medicine. 2009; 123:25-33.
13. Babu Raghavendra YP, Kanchan T, Attiku Y, Dixit PN, Kotian MS. Sex estimation from foramen magnum dimensions in an Indian population. Journal of Forensic and Legal Medicine. 2012; 19(3):162-167. 

Vinutha. S.P, Shubha. R. MORPHOMETRY AND SEXUAL DIMORPHISM IN FORAMEN MAGNUM: A STUDY OF HUMAN SKULL BONES. Int J Anat Res 2016;4(3):2593-2599. DOI: 10.16965/ijar.2016.283