Comparative Analysis of Cranial Bone Thickness in Adult Skeletal Remains

Thesis Abstract

Cranial bone thickness plays a pivotal role in forensic anthropology, bioarchaeology, and clinical neuroanatomy, yet there remains limited comprehensive comparative data across diverse adult skeletal populations. Variations in cranial thickness can influence human skeletal analyses, trauma assessment, and surgical planning, making it essential to understand the factors driving these anatomical differences. This study aims to perform a detailed comparative analysis of cranial bone thickness in adult skeletal remains, focusing on variations across sex, age groups, and geographic populations, to establish normative data and identify statistically significant differences. The specific objectives include quantifying the thickness of key cranial bones—frontal, parietal, occipital, and temporal bones—in a sample of adult skeletal remains; evaluating the influence of demographic variables such as sex and age; and assessing inter-population differences by geographic origin. Employing a cross-sectional, empirical research design, the study analyzed a stratified random sample of 200 adult skeletons sourced from skeletal collections in forensic and archaeological repositories. The population included 100 males and 100 females aged 20 to 80 years, representing four geographic populations (50 specimens each from East Asia, Sub-Saharan Africa, Europe, and South America). Data collection involved precise measurement of cranial bone thickness using digital calipers and computed tomography (CT) imaging, supported by standardized protocols to ensure measurement reliability and validity. Calibration of measurement instruments was conducted prior to data collection, and intra- and inter-observer reliability was assessed via duplicate measurements on a subset of specimens, yielding intra-class correlation coefficients exceeding 0.95. Data analysis employed descriptive statistics to establish mean and standard deviation values for cranial bone thickness across the variables. Inferential analyses included analysis of variance (ANOVA) and multivariate regression to identify statistically significant differences and predictors of cranial thickness. A generalized linear model was specified to account for confounding factors, and post-hoc tests (Tukey's HSD) examined pairwise group differences. Ethical considerations adhered to institutional and international standards for the handling of human skeletal remains, including anonymization and restricted access to identifiable data. Expected findings suggest significant sex-based differences, with males displaying thicker cranial bones across most sites. Age-related decline in cranial thickness is anticipated, particularly in individuals above 60 years. Inter-population analyses are projected to reveal statistically significant variations, with East Asian and European specimens exhibiting greater average cranial thickness than Sub-Saharan African and South American samples, aligning with previous morphological studies. These findings are expected to contribute valuable normative data for forensic and anthropological applications and provide insights into the biological and environmental factors influencing cranial morphology. The study advances existing knowledge by integrating morphological and imaging modalities to generate detailed, population-specific cranial thickness profiles. It underscores the importance of demographic considerations in forensic reconstructions and clinical contexts, facilitating improved estimates of trauma impact and biometric identification. The main conclusion emphasizes that cranial bone thickness is a dynamic trait influenced by sex, age, and genetic ancestry, necessitating population-specific standards in anthropological and forensic assessments. Recommendations include the development of regionally calibrated cranial thickness databases, further exploration of environmental influences on skull morphology, and the refinement of measurement techniques through advanced imaging technologies to enhance accuracy and reproducibility. Future research should focus on longitudinal studies tracking cranial changes over lifespan and integrating genetic analyses to elucidate underlying biological mechanisms.