Ontogeny of morphological variations in the vertebral column: Prevalence and bony variability in young Spanish children.

Pre- and postnatal development and variability in discrete vertebral traits have been poorly described in embryonic studies. Numerous authors have reported that these variations are observable only from adolescence; scientific publications on the vertebrae of fetuses and infants are scarce. Thus, the aims of this study were to (1) describe the ontogeny and variability of anatomical variations in the vertebral column of a Spanish infant population and (2) analyze the frequency and relationship between sex, age, and intertrait variables. A total of 4728 vertebrae from 197 skeletons were studied. The age at death ranged from 22 intrauterine weeks to 8 years. Twenty morphological traits related to vertebral column development were analyzed. A descriptive statistical analysis was performed, and the chi-square test was used to measure the relationship between sex, age, and intertrait variables. We observed that 88.32% of skeletons expressed discrete traits along the spine. In fetuses, the double transverse foramen and unclosed transverse process of the axis were the most prevalent traits. In infants older than one year, the appearance of the L5 cleft neural arch, unclosed transverse process of the atlas, and craniocaudal shifts were frequent. A significant result was found between sex and the unclosed transverse process in the axis. The intertrait relationship was significant for all traits that shared the same embryonic structure. Morphological variations became visible following the appearance of ossification centers during the pre- and postnatal periods, and their etiology was associated with embryonic development.

Sternal human variability and population affinity: Frequency of discrete traits and their relationship with sex and age.

Sternal morphological variations differ among populations and are influenced by the interaction between inheritance, development, and environment. There are currently no studies that include all variability from a morphogenesis approach following a homogeneous definition. The aims of this study were (a) to develop a standardized method for the anatomical study of the sternum; (b) to analyze the prevalence of the morphological variations and their relationship between sex and age; (c) to compare the results with other populations. The sterna of 155 skeletons from a Spanish population were studied. The age at the time of death was 17 to 97 years. We analyzed two metric and 22 sternal morphological variations described in the literature and designed an illustrated atlas. The atlas was validated using the intraclass correlation coefficient (ICC). A descriptive statistical analysis was conducted to measure the prevalence and relationship between sex and age. To analyze the interpopulation variability, we compared our results with those from other authors. The atlas with definitions and reference images improves the observation and detection of all morphological variations of the sternum (ICC = 0.90). The dependence between the morphological traits and sex was significant for the variations in the sternal angle, the number of esternebra, and the development of the xiphoid process. No significant differences were found between age group and morphological traits. The expression of the sternal morphological variation and sex are population-specific. The results will help standardize future studies and provide valuable information on the variability of the sternal morphological variation.

Validation methods of Fazekas and Kósa and Molleson and Cox for age estimation of the ilium in Western Mediterranean non-adult population: proposal of new regression formulas.

The purpose of this study is to test the applicability of the age estimation methods of Fazekas and Kósa [1] and Molleson and Cox [2] in Western Mediterranean non-adults and to develop accurate and rapidly applied formulas for their age estimation, using a sample of 149 non-adults of known sex and age from the cemetery of San José in Granada (Spain). Measurements have been taken of the maximum length and width of each ilium for application of the formulas of Fazekas and Kósa [1] and Molleson and Cox [2]. There has been no significant intra- or inter-examiner variation in measurements. The documented age of the individuals has been underestimated with the Fazekas and Kósa method and overestimated with Molleson and Cox. Based on these findings, new formulas are proposed for the age estimation of non-adults in Western Mediterranean populations.