目的：研究先天性外耳道狭窄、外耳道闭锁患者卵圆窗和圆窗的空间方位特点，探讨其临床意义。方法： 将先天性外耳道狭窄、先天性外耳道闭锁患者和正常人的CT数据三维重建后，计算圆窗龛口平面、圆窗膜平面、 卵圆窗平面、圆窗龛中轴线的空间方位。结果：圆窗膜与法兰克福平面的夹角在外耳道狭窄组（42.43°±25.58°） 小于正常组（66.72°±45.18°）。圆窗膜与矢状面的夹角在外耳道狭窄组（74.70°±17.94°） 小于正常组 （91.62°±21.36°）。圆窗膜与冠状面的夹角在外耳道狭窄组（72.14°±20.10°）和外耳道闭锁组（71.38°±27.59°） 均小于正常组（92.39°±29.36°）。卵圆窗与冠状面的夹角在外耳道狭窄组（103.38°±20.52°）大于外耳道闭锁组 （88.43°±20.14°）和正常组（82.40°±17.25°）。圆窗龛中轴线与矢状面的夹角在外耳道闭锁组（25.38°±7.63°） 大于正常组（17.14°±7.50°）。结论：在先天性外耳道狭窄患者圆窗膜后半部分向外下方倾斜，卵圆窗后半部分 向内下方倾斜。在外耳道闭锁患者，圆窗龛整体向前倾斜。本研究可为经卵圆窗区和圆窗区手术提供解剖学基础， 以避免损伤面神经、圆窗膜和椭圆囊等内耳重要结构。

Objective：To investigate spatial characteristics of the oval window（ OW） and round window（ RW） among a congenital aural atresia （CAA）， a congenital aural stenosis （CAS） and a normal control group， and to explore its clinical significance. Methods ： Three-dimensional reconstructions based on CT images of normal subjects，CAS and CAA patients were processed. The morphological data about the spatial characteristics contained the angles between the round window niche （RWN） opening plane， the round window membrane （RWM） plane， OW plane and the central axis line of RWN. Results ： The angle between the RWM plane and the Frankfurt horizontal plane in the CAS group（42.43°±25.58°） was smaller than that in the control group （66.72°±45.18°）. The angle between the RWM plane and the sagittal plane in the CAS group （74.70°±17.94°） was smaller than that in the control group （91.62°±21.36°）. The angle between the RWM plane and the coronal plane was （90.31°±31.47°） in the control group，（ 72.14°±20.10°） in the CAS group， and（ 71.38°±27.59°） in the CAA group， and this angle in both the CAS and the CAA group were smaller than that in the control group. The angle between the OW plane and the coronal plane were smaller in both the control group （82.40°±17.25°） and the CAA group （88.43°±20.14°） than that in the CAS group （103.38°±20.52°）. The angle between the central axis line of the RWN and sagittal plane was larger in the CAA group （25.38°±7.63°） than that in the control group （17.14°±7.50°）. Conclusion ： The posterior portion of the RWM tends to be more lateral-inferiorly displaced and the posterior portion of the OW is more posterior-inferiorly positioned in patients with CAS. Moreover， the RWN in whole tends to anteriorly tilt in patients with CAA. This study can be helpful to provide the anatomical basis for surgery in the OW and RW area and to avoid iatrogenic injuries of the facial nerve， RWM， and utricle.