Anat Sci Int. 2026 Jan 31. doi: 10.1007/s12565-026-00918-w. Online ahead of print.
ABSTRACT
Although previous research has examined the first lumbar (L1) vertebra for sex estimation, studies focusing on its role in age estimation have been limited. This study expands on earlier work by investigating the morphological variations in shape and size of the L1 vertebra across different age groups within the Malaysian population. A sample of 440 abdominal CT images was collected from the Radiology Department at Universiti Kebangsaan Malaysia Medical Centre. These images included adults aged 18 to 80, who visited the department in 2019. Twenty-seven 3D landmarks were marked on each L1 vertebra using digitized 3D CT scan images. Statistical analyses were performed using a geometric morphometric approach to evaluate age-related variations in the shape and size of the L1 vertebra. Principal Component Analysis identified 74 shape variables describing the shape of the L1 vertebra, with the first five principal components explaining 38.27% of the variance. The Canonical Variate Analysis scatter plot showed slight separation among the confidence ellipses for the three age groups, with significant p-values (p < 0.001). Procrustes ANOVA revealed significant differences in both the size and shape of the L1 vertebra across all age groups. Additionally, multivariate regression of shape on continuous age revealed a significant, biologically meaningful pattern (R² = 0.022, p = 0.001). This study shows that the size and shape of the L1 vertebra differ across various age groups. In elderly individuals, the L1 vertebra is characterized by longer spinous processes and shorter, flatter vertebral bodies. Conversely, younger individuals tend to have L1 vertebrae with shorter transverse spinous processes and taller vertebral bodies.
PMID:41619075 | DOI:10.1007/s12565-026-00918-w
