Sex and stature estimation from adult lumbar vertebrae in a Thai population based on image analysis / Estimación de sexo y estatura de vértebras lumbares adultas en una población Tailandesa basada en análisis de imagen

SUMMARY: 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.

RESUMEN: Los métodos antropológicos de evaluación del esqueleto siguen siendo una herramienta importante en el proceso de identificación en las investigaciones médico-legales. El objetivo de este estudio fue desarrollar una ecuación de función discriminante para estimar el sexo y la estatura utilizando varias medidas de las vértebras lumbares en una población tailandesa. Se estudiaron 150 columnas lumbares (75 hombres y 75 mujeres) con un rango etario de 22 a 89 años del Centro de Investigación de Osteología Forense, Universidad de Chiang Mai, Tailandia. Las variables cuantitativas de sexo se analizaron mediante el análisis de función discriminante y la estatura fue calculada mediante regresión lineal. En cuanto a la determinación de sexo, la densidad de píxeles del eje mayor de superficie trabecular de la placa terminal superior de la primera vértebra lumbar fue de mayor precisión. La ecuación de regresión con variables cuantitativas en la estimación de la estatura describió el 32,3 % de la varianza total con el error estándar de estimación de 7,736 cm. Las vértebras lumbares se pueden utilizar como parte de la estatura y el sexo, estimando cuantitativa y cualitativamente los restos esqueléticos incompletos en sujetos tailandeses.

Age Estimation of Lumbar Vertebrae by Visual Assessment in a Thai Population.

BACKGROUND: The age estimation of bone is essential for identification of the unknown-identity persons in both forensic and anthropological sciences. The lumbar vertebrae carry the most weight; hence, they have more biomechanical stress than any other vertebrae. As a result, the degenerative changes commonly occur in them. However, the estimation from visual assessment in lumbar vertebrae has not been reported in a Thai population. OBJECTIVE: To evaluate the age estimation from the degree of osteophyte formation, the macroporosity, and the cortical surface to develop equations of lumbar vertebrae. MATERIALS AND METHODS: A total of 250 lumbar columns (125 males and 125 females) in age range of 22 to 89 years were collected from the Forensic Osteology Research Center (FORC), Faculty of Medicine, Chiang Mai University. RESULT: The most appropriate linear regression equation was used to estimate age by the inferior surface of L1 vertebra (R2= 0.408) with the standard error of 11.686 years. CONCLUSION: It was clear to recognize that three morphological aspects will be useful methods for forensic situations.

The interlaminar and the narrowest distances at the L3/4 and L4/5 interspinous spaces and location of the intercrestal line in Thai cadavers.

BACKGROUND: Data on the L3/4 andL4/5 interspinous distances are important in performing a lumbar puncture. This has not been studied in Thais. OBJECTIVE: To study the interlaminar and the narrowest distances at theL3/4 and L4/5 interspinous spaces and location ofthe intercrestal line in Thai cadavers. MATERIAL AND METHOD: The interlaminar and the narrowest distances at the L3/4 and L4/5 interspinous spaces and location of the intercrestal line were measured in 87 cadavers. Mean age of cadavers was 66.7±10.6 years (range 40-80 years). Measurements were statistically analyzed using unpaired t-tests. RESULTS: The intercrestal line most often intersected at the lower halfofthe L4spinousprocess (32/87, 36.8%), rangingfrom the lower half ofL3 spinous process to the upper half of Si. Mean interlaminar and the narrowest distances at the L3/4 interspinous space were not significantly different from the L4/5 interspinous space: 7.32±2.7 mm vs. 7.05±3.0 mm and 5.27±2.1 mm vs. 5.38±2.4 mm, respectively (p> 0. 05). These interspinous process distances in 71-80year old cadavers were significantly shorter than 40-60 and 61-70 year age groups (p<0.05). CONCLUSION: The present study confirms that the intercrestal line is most commonly at the lower half of the L4 spinous process. Mean interlaminar and the narrowest distances at the L3/4 and L4/5 interspinous spaces were unrelated to gender or body type. The elderly had more narrow interspinous process distances which may be benefitfrom having lumbar puncture done in the sitting andfeet supported position.