Sexual dimorphism of foramen magnum using South Indian dry skulls

 

Geethika. B¹*, Dr. Thenmozhi²

¹BDS-I, Saveetha Dental College, Chennai.

²Head of Department, Department of Anatomy, Saveetha Dental College, Chennai.

 

ABSTRACT:

Sexual dimorphism plays an inevitable role in the field of forensics. Previous studies done have shown foramen magnum to show significant morphometric difference with sexual difference but it varies from race to race. This study aims to contribute to the existing evidence for better knowledge.

 

 

 

INTRODUCTION:

Foramen magnum is a three dimensional opening within the basal area of the occipital bone. The structures that are transmitted by this aperture include the medulla oblongata and its membranes, vertebral arteries, the spinal accessory nerve, anterior and posterior spinal arteries, membrana tectorium and alar ligaments.(1) The variations in dimensions of the foramen magnum due to compression in cases such as foramen magnum herniation, foramen magnum meningiomas and foramen magnum achondroplasia. This has a great clinical importance the above mentioned vital structures pass through it. (2)

 

The location of foramen magnum plays a crucial role in understanding the evolution. Compared to others read of the skull foramen magnum shows increased resistance to physical stress and inhumation. (3)

 

Many authors have classified foramen magnum depending upon its shapes, such as egg shaped, oval, tetragonal, round, pentagonal, hexagonal and irregular (2,4,5)

 

Sex determination is one of the first steps in the identification of any human skeletal remains discovered with regard to forensics or archaeology. (7)

 

Catalina-Herrera (1987) indicated that the sagittal and transverse dimensions of the foramen magnum were significantly higher in men’s skulls. Various studies have reported that significant differences exist in the morphometry of foramen magnum between the two sexes within a restricted geographical region and historical period.  (4,6,7)

 

MATERIALS AND METHOD:

Fifty dry South Indian skulls of known sex were taken. Skulls that were damaged were excluded from the studied. The sample for the study were examined from Saveetha Dental college, Chennai. The measurements were recorded using a digital vernier calliper. The Anteroposterior diameter of foramen magnum which is the distance between Basion and opisthion was measured. Transverse diameter of foramen magnum is the distance measured at right angles to anteroposterior diameter of foramen magnum was also noted. The measurements were taken by a single observer and was checked twice to avoid errors.

 

RESULTS AND DISCUSSION:

The mean of maximum transverse diameter of foramen magnum in males was to be 28.217 and in females it was 24.245 with a standard deviation of 3.001 and 3.011 respectively. The mean of maximum anteroposterior diameter in males is 33.072 and in females is 26.266 with a standard deviation of 2.356 and 2.188 respectively.

From the above results we can see that the dimensions of foramen magnum- both anteroposterior and transverse is significantly higher in the male population. These results are consistent with most of the literature that were analysed. It is also seen that these values differ for different population and are the lowest in a population that has large ethic mix. (8,9,10)

 

Statistics of Foramen Magnum
	Sex	Mean	SD
Maximum transverse diameter	Male	28.217	3.001
	Female	24.245	3.011
Maximum anteroposterior diameter	Male	33.072	2.356
	Female	26.266	2.188

 

CONCLUSION:

In the present study the Anteroposterior and transverse diameter of the foramen magnum of male and female South Indian skulls were recorded.  The morphometric analysis of foramen magnum is important to anatomists, anesthetists, orthopedicians, neurosurgeons, radiologists, forensic scientist. Determination of sex is an important and inevitable procedure in forensics. The following study will add to the existing evidence in the field of forensics.

 

REFERENCES:

1.     Scheuer L, Black S. The Juvenile Skeleton. Elsevier, London.200 I Pp 55, 148

2.     Murshed K A, Cicekeibasi A E, Tuncer I. Morphometric evaluation of the foramen magnum and variations in its shape. A study of computerized tomographic images of normal adults. Tur J Med Sci 2003;33:301-306.

3.     Krogman WM, Iscan MY. 1986. The human skeleton in forensic medicine. Springfield, Illinois: Charles Thomas Pub Ltd.

4.     Radhakrishna SK, Shivarama CH, Ramakrishna A, Bhagya B. Morphometric analysis of foramen magnum for sex determination in South Indian population. NUJHS, March 2012; 2(1): 20-22.

5.     Chethan P, Prakash KG, Murlimanju BV, Prashant KU, Prabhu LV, Saralaya VV et.al Morphological Analysis and Morphometry of the Foramen Magnum: An Anatomical Investigation. Turkish Neurosurgery 2012; 22 (4): 416-419

6.     Suazo GIC, Russo PP, Zavando MDA, Smith RL, Sexual dimorphism in foramen magnum dimensions. International Journal of Morphology; 2009; 27(1): 21-23.

7.     Manoel C, Prado FB, Caria PHF, Groppo FC. Morphometric analysis of the foramen magnum in human skulls of brazilian individuals: its relation to gender . Braz. J. Morphol. Sci 2009; 26(2): 104-108.

8.     Suazo, G. I. C.; Zavando, M. D. A. and Smith, R. L. Evaluating accuracy and precision in morphologic traits for sexual dimorphism in malnutrition human skull: a comparative study. Int. J. Morphol., 26(4): 876-83, 2008a.

9.     Suazo, G. I. C.; Zavando, M. D. A. and Smith, R. L. Accuracy of palate shape as sex indicator in human skull with maxillary teeth loss. Int. J. Morphol., 26(4):989-93, 2008b.

10.   Suazo, G. I. C.; Zavando, M. D. A. and Smith, R. L. Sex determination using mastoid process measurements in Brazilian skulls. Int. J. Morphol., 26(4): 941-4, 2008c.

 

 

Accepted on 20.07.2016        © RJPT All right reserved

Research J. Pharm. and Tech 2016; 9(11): 1867-1868.