Sex and Stature Estimation from Adult Lumbar Vertebrae in a Thai Population Based on Image Analysis

Abstract

Although molecular techniques evolved considerably in last years, anthropological methods of assessing skeletal remains, continues to be an important tool in the identification process in medico legal investigations. The objective of this study was to develop a discriminant function equation for estimating sex and stature using several measurements of lumbar vertebrae in a Thai population. We studied 150 lumbar columns (75 male and 75 female) age range of 22 to 89 years from the Forensic Osteology Research Center, Chiang Mai University, Thailand. The quantitative variables with sex were analyzed by the discriminant function analysis and that with stature were calculated using linear regression. The pixel density of the major axis of the trabecular surface of superior endplate of the first lumbar vertebra had the most accuracy in sex determination. The regression equation with quantitative variables in stature estimation described 32.3 % of the total variance with standard error of estimate of 7.736 cm. Lumbar vertebrae can be used as part of the stature and sex quantitatively and qualitatively estimating in Thais incomplete skeletal remains.

Deep learning and morphometric approach for Sex determination of the lumbar vertebrae in a Thai population

“…19 Suwanlikhid et al used dry bone and image analysis which had an accuracy of 81.8% from the discriminant equation of L1. 18 The results of using deep-learning image classification on dry bone images in this study were satisfactory. Similar to other studies that used different types of medical images to determine sex, the utilization of CT-scanned pelvic images had accuracies between 94% and 98.5%, whereas the lumbar spine X-ray images achieved an accuracy of 98%, and hand radiograph was able to correctly determine sex with an accuracy of 98%.…”

“…31 The mean age of the subjects is similar to a previous study that used CT images and 2D dry bone images. [17][18][19][20] The previous studies showed that age did not impact the results of sex determination from the vertebral body. Using dry bone is useful in burned events that causes bones to be fragmented.…”

“…Similarly, previous sex estimation studies which investigated all levels of lumbar vertebrae reported decreased accuracy decreasing from the first to the fifth lumbar vertebra. [17][18][19] For instance, Ostrovsky et al suggested that the lower lumbar region presents less pronounced sexual dimorphism. 9 In archaeology, the vertebral column is a bone fragment that can be identified due to its density.…”

“…14 Numerous studies have stated that sexual dimorphism is most correlated with the size of the vertebral body, and lumbar vertebrae offer an accuracy range of 47.0% to 94.5% for sex determination. 3,4,9,[15][16][17][18][19][20][21] The lumbar upper endplate depth and width variables are found to be useful for sex determination by discriminant function analysis. 13 Sex determination studies based on lumbar vertebral morphometry utilize various techniques, including computed tomography (CT), magnetic resonance imaging (MRI), and dry bone.…”

“…Morphometric assessment is capable of sex determination from all levels of lumbar vertebrae, with accuracy dependent upon the level of lumbar vertebra used, the parameters, study population, and measurement methods. 3,4,9,[15][16][17][18][19][20][21] Although morphometric methods are effective, they are highly dependent on the observer's experience to assess the parameters, and they can still be subject to measurement errors. 22 In recent years, deep learning (DL) has been increasingly included in various studies because it automatically extracts features from numerous images and then performs image classification.…”