Population differences in the morphology of the first cervical vertebra

Cephalometric radiographs from 180 healthy Caucasian females, 90 of whom lived in the north of Finland and 90 in the south, were analysed with respect to the morphology of the atlas vertebra. The main findings were a smaller dorsal arch height and a larger ventral arch height in those from the north, including a longer atlas vertebra. These results are interpreted as evidence of morphogenetic reactions to changes in function, in this case a raised head posture attributable to climatic conditions.