Estimation of sex and assessment of age based on morphological variations of the atlas vertebra (C1) using Cone Beam Computed Tomography: A retrospective study

Abstract

Background The atlas (C1) vertebra joins the cervical column to the cranial base and differs anatomically from other cervical vertebrae. Skeletal analysis may provide the only way to assess biological sex and age in poorly preserved and decomposed remains to estimate their biological profile. It is thus essential that methods are devised that allow such estimates from a wide range of bones. Aim This study applies Cone Beam Computed Tomography (CBCT) to evaluate whether the C1 vertebrae can be used in estimating age and sex. Materials and Methods CBCT of 61 male and 61 female subjects from South India with an age range of 20-60 years were included in the study, and C1 vertebrae were measured using axial and coronal sections. Data were analysed to gen¬erate an equation to predict age according to independent variables using linear regression, while discrimi¬nant analysis was used to derive an equation that classifies the values into either biological sex. Results Male subjects showed higher maximum anteroposterior diameter, maximum transverse diameter, and the distance between the base of the skull and the anterior tubercle than females (p=0.001). The highest standard error for males was observed in the maximum anteroposterior diameter. The base of the skull to the anterior tubercle had the highest standard error among female subjects. The base of skull to posteriori tubercle had the lowest standard error for males, while the angulation from the transverse to the anterior tubercle had the least standard error for females. The accuracy of sex classification was 89.3%. How¬ever, parameters did not demonstrate sufficient reliability for age estimation. ConclusionThe presented parameters may be used for sex determination in forensic identification and other medico-legal practices. In contrast, these parameters are not reliable for age estimation in our sample.