正常人面神经管垂直部与外耳道解剖位置关系的影像与临床研究

Imaging and clinical study of the location relation between vertical facial nerve canal and external acoustic meatus in normal people

目的观察、测量面神经管垂直部毗邻解剖关系及乳突的形态学指标,分析面神经管垂直部和外耳道后壁、外耳门后缘位置变化的相关性,探讨乳突气化程度与面神经管垂直部之间的关系及临床意义。方法1.评价CT影像测量相关结构的正确性,采用64层螺旋CT对4具干颅标本进行扫描,在横断位测量面神经管垂直部至外耳道后壁、外耳门后缘的距离,在矢状平面上测量乳突的前后径(外耳道下壁最低点至乳突后缘的水平距离)和高度(外耳道下壁至乳突尖的垂直距离);按影像层面锯开标本,对上述距离行实体测量。影像测量均值与实体测量均值的差异行显著性检验。2.在体研究:随机入选无耳部疾患的118人(236侧),其中男性55例(110侧),女性63例(126侧),行颌面部CT扫描。如上选择层面,并测量面神经管垂直部至外耳道后壁、外耳门后缘及乳突前后径和高度的距离,以乳突前后径与高度乘积的1/2定义为乳突面积,以乳突面积的大小来定义乳突气化程度,同时将乳突面积分别与面神经管垂直部至外耳道后壁、外耳门后缘距离分别进行相关和回归分析。结果1.标本部分:各项指标的影像测量值与实体测量值差异无统计学意义(P>0.05)。2.在体研究:各项指标测量结果侧别差异无统计学意义(P>0.05),性别差异有统计学意义(P<0.05)。乳突面积与面神经管垂直部至外耳道后壁距离之间呈负相关性,且相关性有统计学意义;乳突面积与面神经管垂直部至外耳门后缘有相关性,但相关性无统计学意义。结论乳突发育气化好,面神经垂直部位置偏前。CT检查可以明确面神经管垂直部与外耳道后壁的关系,有助于耳外科手术术式的选择以及对术中重要结构损伤的控制。

Objective To observe and measure the anatomical structure of approach of vertical facial nerve canal and put forward the normal measurement range and the location relationship among the vertical segment of facial nerve canal, the posterior wall of external acoustic meatus and the rear edge of external ear, and discuss the relationship and clinical significance between the mastoid gasification and the vertical segment of facial nerve canal. Methods 1. Evaluate the accuracy of CT image of related structure, using spiral CT in scanning four skull specimens, get the horizontal distances of the vertical segment of facial nerve canal to the posterior wall of external acoustic meatus and the rear edge of external in the axial position, and get the sagittal diameter of mastoid （the horizontal distance from the lowest point of external auditory inferior canal to the rear edge of mastoid） and the height （the vertical distance between the lowest points of the external auditory canal wall to the mastoid tip） in the sagittal position. And then saw the skull specimens to measure the distance in the same lay with CT image, and discuss the statistics difference of the distance between the values of CT imaging measurements and the dry entities cranial measurements on hand. 2. Study on people： 118 patients （236 sides） with non-ear disorders were randomly selected, among which there were 63 females （126 sides） and 55 males （110 sides） . They were subjected to maxillofacial CT scan in the same layer that used above, and the horizontal distances of the facial nerve eanal to the posterior wall of external acoustic meatus and the rear edge of external ear were measured. In addition, half of the product of diameter and height of the mastoid was defined as mastoid area, which was used to define tile extension of mastoid gasification. Then related analysis and regression analysis were done between the vertieal segment of facial nerve canal and the posterior wall of external acoustic meatus, as well as the rear edge of external ear. Results 1. Part of the experiment： There was no signifieantly different on the indicator values between CT image the entity measurements among the four skull specimens （ P 〉 0.05） . 2. Study on people： There was no significantly different between left side and right side（ P 〉 0.05）, but significantly different t）etween genders（ P 〈 0.05） . Between mastoid area and the distance from the vertical segment of facial nerve canal to the posterior wall of external acoustic meatus there is inverse correlation, and the relevance has the remarkable significance. However, ~here was no correlation between mastoid area and the vertical segment of facial nerve canal to the rear edge of external ear. Conehlsion There was some relationship between the location of the vertical segment of facial nerve canal and external aeoustic meatus. Anatomic position of vertical facial nerve eancal and the posterior wall of external acoustie meatus can be showed clearly. CT and in eombination with primitive axial images may provide reliable evidence for the diagnosis facial nerve dieases and the choice of ear surgery route.