The size and shape of the human pelvis: a comparative study of modern and medieval age populations

Sex Estimation Through Orbital Measurements: A Machine Learning Approach for Forensic Science

BACKGROUND

Sex estimation has been extensively investigated due to its importance for forensic science. Several anatomical structures of the human body have been used for this process. The human skull has important landmarks that can serve as reliable sex estimation predictors.

METHODS

In this study, orbital measurements from 92 dried skulls, comprising 35 males and 57 females, were utilized to develop a machine-learning-based classifier for sex estimation with potential applications in forensic science. The parameters evaluated included optic foramen height (OFH), optic foramen width (OFW), optic canal height (OCH), optic canal width (OCW), intraorbital distance (IOD), extraorbital distance (EOD), orbit height (OH), and orbit width (OW).

RESULTS

A Random Forest classifier was employed to analyze the data, achieving an overall test accuracy of 0.68. The model demonstrated a precision of 0.65, indicating a moderate level of false positives. The recall was 0.70, reflecting that 70% of the positive cases were correctly identified. The F1 score was calculated at 0.675, suggesting a balanced performance between precision and recall. The area under the curve (ROC AUC) score was also 0.72, indicating that the model can distinguish between classes. The most important features in the best subset were OW (0.2429), IOD (0.2059), EOD (0.1927), OFH (0.1798), and OFW (0.1787), highlighting their significant contributions to the model's predictions.

CONCLUSIONS

These findings suggest that orbital measurements could potentially serve as reliable predictors for automated sex estimation, contributing to advancements in forensic identification techniques.

Radiographic Study of L5-S1 Transforaminal Endoscopic Access in a Sample from the Brazilian Population

Objective  This study evaluated lumbar spine radiographs using the Choi and Patgaonkar classifications to verify parameters potentially influencing the L5-S1 transforaminal approach. Materials and Methods  We studied 167 lumbosacral spine radiographs from patients over 18 years old with no history of surgeries, tumors, fractures, or scoliosis to measure the iliac crest height and rim angle. We categorized the cases per pelvic morphology, mega-apophysis presence, and Choi and Patgaonkar classifications. Results  Seventy-five cases had an android pelvis and 92 had a gynecoid pelvis. The mean iliac height was 25.9 ± 7.5 cm, and the rim angle was 23.4 ± 7.5 degrees. The gynecoid pelvis showed a lower iliac height. According to Patgaonkar, 63 cases indicated a suprailiac approach, and per the Choi classification, 37 were suitable for a suprailiac approach and 106 for a suprailiac approach with foraminoplasty. Conclusion  Gynecoid pelvises had a lower iliac height. Furthermore, 37.7% of the cases were suitable for a suprailiac approach per the Patgaonkar classification. The Choi classification indicated a suprailiac approach for 22.1% of the cases and a suprailiac approach with foraminoplasty for 63.4% of the subjects.

A survey of pelvic types on computed tomography images

BACKGROUND

In the medical literature several classifications of the pelvis according to its shape can be found. The most common classification distinguishes four general pelvis types: gynecoid, android, anthropoid and platypelloid. Natural childbirth may be significantly prolonged, difficult or even impossible if the pelvis shape is not in proportion to the size of the fetus. The objectives of our study were to calculate major diameters and conjugate diameters of the female bony pelvic ring and to determine the major pelvic types according to their shape. Based on the parameters obtained, we aimed to establish a relationship between some pelvic types and difficult childbirth.

METHODS

The study was prospective in design and included 54 female subjects of various ages who had been referred for computed tomography of the pelvis, as part of the diagnosis of an underlying condition. In each patient, five most important parameters in two planes were measured and the pelvic type was determined by using the brim index and a special formula for android type. All measurements were performed using the Vue PACS v 12.1.6.1005 program. The description of the pelvic inlet was used to confirm all pelvic types. Data on previous births were taken from the questionnaire filled out by the subjects during the radiological examination.

RESULTS

Gynecoid pelvic type was the most common in our sample (28 pelvises - 52%), followed by platypelloid type (11 pelvises - 20%), anthropoid type (8 pelvises - 15%) and finally android type (7 pelvises - 13%). There was a statistically significant difference in the diameter bispinous length (p<0.05) between the platypelloid and anthropoid pelvic types. Pathological degree of stenosis was present in seven pelvises (the first degree in six pelvises and the second degree in one pelvis). The frequency of cesarean section was 31.82% and this technique was most frequently used in the subjects with a gynecoid pelvic type. The duration of natural labor ranged from 4 to 18hours. There was no statistically significant difference in the duration of labor between subjects with different pelvic types.

CONCLUSIONS

Gynecoid pelvic type was present in more than half of our subjects. Although this type is considered ideal for labor, we have not established that it has a great influence on whether the labor will be performed naturally or by cesarean section, neither that it significantly affects the length of birth. The gross narrowing of the pelvic ring is present in non-gynecoid pelvic types. The data obtained will certainly be useful to the obstetrician when planning the labor and considering all the factors that may affect the course of birth.