Atlas: 19.3% of the inside oblique angle of superior articular face, 10.7% of outside oblique angle of inferior articular face and 7.3% of inside oblique angle of aside massa were asymmetry.

• 寰椎上关节面内倾角、下关节面外倾角及侧块内倾角两侧不对称分别占 19.；3%25、10