Sex Determination from Measurements of the Sternum Using Multislice Computed Tomography of the Chest in Pashtun Population of Swat
DOI:
https://doi.org/10.31580/pjmls.v4i4.2261Keywords:
Sternum, Male, Female, Sexual dimorphism, Pathan, SwatAbstract
This study was designed to study for the first time sexual dimorphism in the sternum bone of a specific race Pathan of district Swat Khyber Pakhtunkhwa. It is hypothesized that the osteometric traits of the sternum will be sexually dimorphic in the peoples of District Swat. The target population was among the patients who came to Radiology Department Saidu Teaching Hospital Swat for routine investigations with multi-slice computed tomography for chest problems. The population included in the study were, adults aged ranged from 20 to 60 years old, and had no chest wall pathology. A total of 260 (130 each male and female) patients were selected. The parameters studied were sternal area, manubrium length, sternal length, manubrium width and sternal width at two levels. There was a significant difference in the sternum of male and female in the Pashtoon population of Swat. All the measurements were significantly (p <0.001) lower in females as compared to the males population. The most important prediction of gender is manubrium length, manubrium width and body length. There were the most useful dimensions of the sternum to discriminate genders. In other words, due to the significant differences in the dimensions of the sternum in various ethnicities, gender differentiation is possible by examining all studied parameters.
References
In this research, we observed statistically significant differences (p>0.05) for manubrium length (ML) between the studied genders. Parallel to our results, earlier studies on the same sternal measurements also stated significant differences (p<0.05) between the genders (22,23). The average manubrium length of male and female obtained in this study was 5.51±0.74 and 5.21±0.77 cm, respectively. Evaluating morphological resemblances and variances in sternal osteometric data with the earlier reports are important for assessing the consistency of measurement methods. However, different values are reported for ML measured through MDCT images in a different population and regions of the world for male (M) and female (F) i.e. M: 6.07± 1.07cm, F:6.0 ±.61 cm (23), M: 4.626 cm, F: 4.3 cm (24), M:5.39cm, F: 5.03 cm (16), within the Turkish population and M:5.25 cm, F:4.82cm, (8). The average manubrium width (MW) of male and female calculated in this study was 5.95±0.77 cm and 4.49±0.40 cm, respectively. (M:4.37cm, F:4.85cm) Hindustan population (25), (M: 4.39cm, F: 4.70cm) in Europe population (26), (M:4.84cm, F:5.14cm) in United States population (22). Therefore, osteometric standards for a specific population cannot be applied generally. The differences in the findings of the current study, with the previous studies, maybe due to the regional variances. Similar to manubrium length, different values are reported for MW measured through MDCT images in different populations and regions of the world i. e. M: 5.97± 1.17cm, F: 5.51 ± .11 cm (23). The findings of all these studies conducted in different geographical conditions are showing some similarities and also have differences with our study. It can be inferred from this study and previous reports that the values of sternum-related dimensions are very different and heterogeneous in various populations.
The Bwa (Body width A) and BWb (Body width B) were found to be significantly higher (<0.001) in males than females population. Analogous results were reported (25) for the peoples of (26) for the subjects of Northwest Indian. Parallel to our results, earlier studies on the same sternal measurements also stated significant differences (p<0.05) between the genders (22,23). Contrary to this study, (16) observed in African subjects that the Bwa were not significantly higher in male than female. The Bwa measured in the present was 3.15 ± 0.47 cm and 2.86 ± 0.34 cm, in male and female in the individuals of Swat. Nearly similar values (3.25 ± 0.17 cm and 2.75 ± 0.14 cm) were reported for Body width A (23). From the results of this study and earlier studies, it can be concluded that the Bwa and Bwb are also a predictor of gender identification. However, a disagreement with this study, (26) stated that the Bwa and Bwb values cannot be applicable for differentiating genders in the Iranian subjects.
In the present study, the total sternal area was significantly higher (<0.001) in male than the female population as narrated for Croatia population (27). The total sternal area measured in this research was 67.09±8.86 cm2 and 50.03±6.82cm2 for male and female patients, respectively. Nearly similar values (M: 63.86±7.68 cm2, F: 50.26±7.45 cm2) to our study were reported for Croatia population for the total sternal area (27). The total sternal area in the present study also provides accurate criteria for sex identification. It was concluded from the current study that total sternal area alone may be used for sex estimation in forensic studies. We had noted differences in all measurements of the male and female sternum. We did not further elaborate on the structure of sternum for other differences. However, (27) found no difference in the general structure of the sternum (27).
In our study, the manubrium length was highly correlated to gender, thus can easily be used for discriminating genders. The manubrium length and width of males were also significantly longer than females. According to (28), all sternal measurements were significantly greater in the males linked to the females. In this favour, the length of the manubrium had the highest correlation in both genders. Parameters measured for the sternum were greater in males compared to females (p < 0.001). In another similar study, conducted by (29) reported that manubrium length had the maximum correlation coefficient in both males and females (correlation coefficient: 0.721 and 0.740, respectively). These observations incurred from this study and the previously reported data recommend that sternal lengths measurements can be used for the assessment of sex. However, among the sternum measurements, ML and MW were obtained as the most reliable sternal lengths for approximating sex with an accuracy rate of over 90 %.
In the previous studies, the pelvic and craniofacial morphometric parameters yielded 95% and 77.15%, accuracy for sex estimation, respectively (30,8). The pelvic and craniofacial bones provided the highest accuracy for sex estimation in the past, however, the sternum, did not explore thoroughly for sex estimation, give (91.5%) the most accurate predictor of gender in the current study. The sternum was also reported to provide over 80% sex discrimination property (8). The results of the present study can declare the usefulness of sternum for estimation of gender from the human remnants. The findings of our current research are parallel with earlier reported data from several researchers (2,31,16).
The limitations of our study included the possibility of observers bias in the measurement of the sternum and been keeping in mind that gender may be a different measurement as this was not a double-blind study. Other limitations may include the possible osteopenia especially in our female population which may affect the development of bones including the sternum. Also due to anaemia either because of nutritional deficiency or because of menstrual bleeding in female many have affected the hematopoietic site in sternum so may affect the size.
The Bwa (Body width A) and BWb (Body width B) were found to be significantly higher (<0.001) in males than females population. Analogous results were reported (25) for the peoples of (26) for the subjects of Northwest Indian. Parallel to our results, earlier studies on the same sternal measurements also stated significant differences (p<0.05) between the genders (22,23). Contrary to this study, (16) observed in African subjects that the Bwa were not significantly higher in male than female. The Bwa measured in the present was 3.15 ± 0.47 cm and 2.86 ± 0.34 cm, in male and female in the individuals of Swat. Nearly similar values (3.25 ± 0.17 cm and 2.75 ± 0.14 cm) were reported for Body width A (23). From the results of this study and earlier studies, it can be concluded that the Bwa and Bwb are also a predictor of gender identification. However, a disagreement with this study, (26) stated that the Bwa and Bwb values cannot be applicable for differentiating genders in the Iranian subjects.
In the present study, the total sternal area was significantly higher (<0.001) in male than the female population as narrated for Croatia population (27). The total sternal area measured in this research was 67.09±8.86 cm2 and 50.03±6.82cm2 for male and female patients, respectively. Nearly similar values (M: 63.86±7.68 cm2, F: 50.26±7.45 cm2) to our study were reported for Croatia population for the total sternal area (27). The total sternal area in the present study also provides accurate criteria for sex identification. It was concluded from the current study that total sternal area alone may be used for sex estimation in forensic studies. We had noted differences in all measurements of the male and female sternum. We did not further elaborate on the structure of sternum for other differences. However, (27) found no difference in the general structure of the sternum (27).
In our study, the manubrium length was highly correlated to gender, thus can easily be used for discriminating genders. The manubrium length and width of males were also significantly longer than females. According to (28), all sternal measurements were significantly greater in the males linked to the females. In this favour, the length of the manubrium had the highest correlation in both genders. Parameters measured for the sternum were greater in males compared to females (p < 0.001). In another similar study, conducted by (29) reported that manubrium length had the maximum correlation coefficient in both males and females (correlation coefficient: 0.721 and 0.740, respectively). These observations incurred from this study and the previously reported data recommend that sternal lengths measurements can be used for the assessment of sex. However, among the sternum measurements, ML and MW were obtained as the most reliable sternal lengths for approximating sex with an accuracy rate of over 90 %.
In the previous studies, the pelvic and craniofacial morphometric parameters yielded 95% and 77.15%, accuracy for sex estimation, respectively (30,8). The pelvic and craniofacial bones provided the highest accuracy for sex estimation in the past, however, the sternum, did not explore thoroughly for sex estimation, give (91.5%) the most accurate predictor of gender in the current study. The sternum was also reported to provide over 80% sex discrimination property (8). The results of the present study can declare the usefulness of sternum for estimation of gender from the human remnants. The findings of our current research are parallel with earlier reported data from several researchers (2,31,16).
The limitations of our study included the possibility of observers bias in the measurement of the sternum and been keeping in mind that gender may be a different measurement as this was not a double-blind study. Other limitations may include the possible osteopenia especially in our female population which may affect the development of bones including the sternum. Also due to anaemia either because of nutritional deficiency or because of menstrual bleeding in female many have affected the hematopoietic site in sternum so may affect the size.
