1. A general survey was made on the foramen rotundum of the external basal surface of the cranium in 60 adults. 60具成人颅骨颅底外面的圆孔观察和测量结果表明：圆孔多呈圆形，其次是卵圆形，其它形较少见。
2. Objective:To develop rational surgical approach and to further improve the surgical outcomes to foramen magnum tumors. 目的：探讨枕骨大孔区腹侧肿瘤的合理手术入路，进一步提高其手术治疗效果。
3. Objective To study the mechanism and differential diagnosis of cervical nerve compression syndrome of the external intervertebral foramen. 目的研究椎孔外颈神经卡压综合征的机制及其与颈椎病的鉴别方法。
英英解释
n.
1. a natural opening or perforation through a bone or a membranous structure
