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Compression in the head-neck complex often causes fractures of the first cervical vertebra (C1). The type of fracture often determines whether the injury is stable or unstable, which significantly affects the ultimate injury severity. The often unstable bursting fracture of C1 is thought to be caused by a transformation of axial compressive forces into lateral bursting forces by the wedge-shaped lateral masses. The purpose of this study was to measure the orientation of the joint surfaces of C1 to determine whether this symmetry exists. An additional goal was to determine whether the orientation of the joint surfaces varied significantly with location on the surface. Direct measurements of surface coordinates were taken from 40 dried vertebrae. The angles of two areas on each of the four joint surfaces of the lateral masses of C1 were then calculated. The resulting angles agreed with previous investigations of upper cervical vertebral anatomy.