Indian Academy of Forensic Medicine (IAFM) - Official website of IAFM

More documents

Recommendations

Info

J Indian Acad Forensic Med. Jan- March 2012, Vol. 34, No. 1 ISSN 0971-0973 the area and were supplied from cadaver dissection for routine teaching purpose. Osteometric measurements were taken by a technical quality divider and metallic (steel) graduated scale with readings up to one mm. All measurements were taken keeping the bone in the anatomical positions. To test the intra observer differences and repeatability of those measurements ten randomly selected hipbones were measured after one week and the values of the two groups were tested by a paired t test. No significant difference was found in the two measurements of all the three variables. The following measurements (in cm.) were taken. (Figure 1) 1. Sciatic notch width (AB): Measured from the ischial spine to the pyramidal process of the posterior border of the ilium. 2. Acetabular height (CD): This is the vertical diameter of the acetabulum measured along the axis keeping the bone in anatomical position. The Sciatic notch /Acetabular index (SAI) was calculated for each bone from the following formula – SAI = AB/CD x 100 Metric data was summarized as maximum, minimum, range, mean and standard deviations. One-Sample Kolmogorov-Smirnov Test was used to examine the normality of the distribution. Sectioning point (sum of the mean of the two sexes divided by two) was obtained for each variable. Student t-Test for independent sample was performed to examine the difference in the means of the variables in the two groups. Sex was determined by using the Kelley’s rule and compared with the documented sex of the bone. Subsequent sectioning point for the sciatic notch /acetabular ratio was calculated from the sample and it was applied for to determine the sex of the bone. This new rule of thumb was then compared with the Kelley’s and examined in the sample under study. Statistical analysis was performed using SPSS software version 10.0 for windows. A two-tailed P value of less than 0.05 was considered significant. Results: The table 1 and 1A shows the summary statistics of the variables used in the present study. The sciatic notch width in males was 4.39 and in females it was 4.91cm. The mean acetabular height in cm for the male and female were 5.29 and 4.80 respectively. The results of t-Test are seen from table number 2.The t-test indicates that there is significant difference in the mean sciatic notch width and Kelley’s index between male and 28 female. The acetabular height was also significantly different in the two sexes. (t = 6.95, degree of freedom = 28, p value= .000) Table 3 shows the results of applying Kelley’s rule of thumb approach to the study sample in the present series. It was observed that moderate 76.7% of the total bones could be correctly classified into its proper sex. Of these, 64.28% of the male bones and 87.5% of the female hipbones were classified correctly by the Kelley’s rule. According to Kelley’s method bones with sciatic notch /acetabular height ratio equal or greater than 88 were female while those with values less or equal to 86 were male. Table 4 shows the sectioning point obtained for the variables in the present series. For the Kelley’s index the sectioning point for Indian Bengali sample was 0.93.The Kelley’s index was significantly greater in females than in males (t= 8.39, degree of freedom = 28, p= 0.000). Thus we computed the cut off value of 0 .93 from the present series and formulated a new rule of thumb (Hereafter Called the new rule). The new rule was as follows. Bones with sciatic notch /acetabular height index equal or greater than .93 (or 93 when expressed as a percentage) were definitely female and those with values less than .93 were male. Table 5 shows the results of applying the new rule on the present series of Indian Bengali hipbones the results indicate that 93.3 % of the total sample could be correctly classified in to the proper sex. Of those 13 out of 14 (92.8%) of the males and 15 out of 16 (93.75%) of the females were correctly classified by the new rule. Discussion: The present investigation was conducted to examine the applicability of Kelley’s index in sexing hipbones of Indian skeletal remains. The results clearly indicate that the Kelley’s rule of thumb approach could correctly classify only moderate of the hipbones. This is in consonance with works on English and Dutch samples where % could be correctly assigned to its proper sex. [7] Regarding sex specific application of Kelley’s rule the results are better for female than male bones. This fact is contrary to the earlier observation on English and Dutch sample where males could be classified with greater accuracy. This proves, though highly dimorphic, the pelvis shows some racial /population variation in Morphometric. The Kelley’s index was significantly different in the two sexes. The index was greater in females than in males. Taking the individual variables it was seen that the mean Acetabular
J Indian Acad Forensic Med. Jan- March 2012, Vol. 34, No. 1 ISSN 0971-0973 height was more in males and this difference was statistically significant. This finding is in congruence with the observations of investigators on European sample. [6, 7] The sciatic notch width in the present series were comparable with those from a North Indian study [10] that showed the mean width for males was 4.49cm (standard deviation 0.44) and for females it was 4.84 cm (standard deviation of .48)The sciatic notch width is significantly different in the two sexes. The sciatic notch is rather a better indicator of sex in the hipbone as has been postulated by earlier workers. [8, 9, 10, 11] In the present study a new rule of thumb was formulated on the basis of the sectioning point and the standard deviation of the values of the index in the two sexes. On applying this rule 93.3% of the bones could be correctly assigned to its proper sex. These results are better than the Kelley’s approach when applied to the Indian Bengali sample. Thus the present investigation clearly showed that the sciatic notch /acetabular height index is a good method of sexing human hipbones in Indians when the new rule is applied. This will be equally effective even in fragmentary remains as the index can be easily calculated by measuring the two variables. This method has one shortcoming that had also been highlighted by Kelley. The main difficulty lies with defining the exact anatomical landmark for the measurements and the effects of wear and destruction of the bony points in bones that are obtained for forensic casework. Also the chances of inter-observer variations could not be tested in this series, as it was a single author work. However in the present series a standard protocol [10, 11] was followed for the measurement that has been described in the method section. Besides the present work is a preliminary study as the sample comprised thirty fully ossified human bones belonging to the Indian Bengali population. Given the diversity of the Indian population and the results of earlier works [12], such a small sample size is not at all effective in providing results that can be generalized. This approach need to be further worked out with a larger sample preferably in a multicentric study. There is also ample scope to examine the regional variation in Indian bones and its applicability in sexing skeletal remains. It is concluded that the present new rule of thumb approach is a valid, effective, reliable, population specific and easy method to differentiate between male and female pelvis in Indian Bengali skeletal remains. This will have useful application in anthropology, archaeology and Forensic casework involving unidentified 29 human remains belonging, the Indian Bengali population. References: 1. W.M. Krogman, M.Y. İşcan. The Human Skeleton in Forensic Medicine, Charles C. Thomas, Springfield, IL, 1986: 202-08. 2. Bruzek J. A method for visual determination of sex, using the human hipbone, Am. J. Phys. Anthropol. 2002; 117: 157-68. 3. MacLaughlin S.M, Bruce M.F. Sex determination from the pelvis in a Dutch skeletal series, J. Anat. 1985; 140: 532. 4. Albanese J. A metric method for sex determination using the hipbone and the femur, J. Forensic Sci. 2003; 48 (2): 263-73. 5. DiBennardo R, Taylor J.V. Multiple discriminant function analysis of sex and race in the postcranial skeleton, Am. J. Phys. Anthropol. 1983; 61: 305-14. 6. Kelley M.A. Sex determination with fragmented skeletal remains, J. Forensic Sci. 1979; 24(1): 154-58. 7. MacLaughlin S.M, Bruce M.F. The sciatic notch/acetabular index as a discriminator of sex in European skeletal remains. J.Forensic Sci 1986; 31(4): 1380-90. 8. Walker P.L. Greater sciatic notch morphology: Sex, age, and population differences, Am. J. Phys. Anthropology. 2005; 127 (4): 385-91. 9. Milne N. Sexing of human hip bones J. Anat. 1990; 172: 221-26. 10. Singh S, Potturi B.R. Greater sciatic notch in sex determination J. Anatomy 1978; 125: 619-22. 11. Kalsey G, Singla R .K, Sachdeva K. Role of the greater sciatic notch of the hip bone in sexual dimorphism: a morphometric study of the North Indian population Med Sci Law 2011; 51(2): 81–86. 12. Nagesha K.R., Kanchana T, Bastiab B K. Sexual dimorphism of acetabulum–pubis index in South-Indian population Legal Medicine 2007; 9(6): 305-08. Table 1A: Showing summary statistics SEX Statistic SCIATICN Male Mean 4.3929 Std. Deviation .3050 Minimum 4.00 Maximum 5.30 Female Mean 4.9125 Std. Deviation .2778 Minimum 4.50 Maximum 5.30 Range .80 ACETABUH Male Mean 5.2929 Std. Deviation .1817 Minimum 5.00 Maximum 5.60 Range .60 Female Mean 4.8000 Std. Deviation .2033 Minimum 4.40 Maximum 5.10 Range .70 KELLYS Male Mean .8317 Std. Deviation 7.785E-02 Minimum .77 Maximum 1.06 Range .29 Female Mean 1.0237 Std. Deviation 4.511E-02 Minimum .94 Maximum 1.10 Range .17 Table1: Descriptive Statistics of the Variables N Minimum Maximum Mean Std. Deviation KELLYS 30 .77 1.10 .9341 .1151 SCIATICN 30 4.00 5.30 4.6700 .3888 ACETABUH 30 4.40 5.60 5.0300 .3142
Page 1 and 2: J Indian Acad Forensic Med. Jan- Ma
Page 29: J Indian Acad Forensic Med. Jan- Ma
Page 81 and 82:
J Indian Acad Forensic Med. Jan- Ma
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
show all

Indian Academy of Forensic Medicine (IAFM) - Official website of IAFM

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?