Effects of body size on cranial capacity in Korean youth

Cranial capacity is an important parameter in the fields of evolutionary biology and anthropology and is closely related to brain size. Owing to modern imaging technologies such as computed tomography and magnetic resonance imaging (MRI), the exact measurement of cranial capacity is possible. Our group has reported the effects of body size on brain size in Korean youths based on MRI volumetry. However, the effects of body size on cranial capacity and related analyses have not yet been reported in a Korean population. In this study, we constructed three-dimensional models of the intracranial cavities of young Koreans and calculated the volumes. We evaluated the relations of stature and body weight with cranial capacity and analyzed the correlation of cranial capacity with brain volume. Stepwise linear regression showed that body height is a key parameter contributing to cranial capacity, which is expressed by the following equation: (intracranial capacity, cm³) = (11.440 × body height) – 420.03, R² = 0.51. The correlation between intracranial cavity volume and brain volume was strong (r = 0.89), which allowed us to calculate an equation for brain volume based on intracranial cavity volume.