内容介绍：环枕畸形 枕骨畸形– 扁平颅底(platybasia) – 颅底凹陷(basilar impression) 环椎和枢椎畸形– 环椎枕化(atlanto-occipital assimilation) – 枢椎畸形(axis deformity) 枢椎分节不良(axis assimilation) 齿状突发育不良(odentoidproeess hypoplasia) 齿状突分离（o