机械耳点和解剖耳点的相对位置关系研究

Study of the location relationship of mechanical porion and anatomical porion

目的:对机械耳点和解剖耳点的相对位置关系进行测量分析,探讨两点不一致产生的原因。方法:选择正畸初诊患者124例,男42例,女82例,平均年龄11.3岁。用西门子Orthophos3型X光机拍摄头颅定位侧位片。以机械耳点最上缘为原点,以FH平面为X轴,建立直角坐标系。将全部病例两耳点位置关系描记于同一张描图纸上。结果:①解剖耳点和机械耳点的完全重叠率仅为20.1%;②.两点间相对位置关系有4种表现形式;③.解剖耳点多位于机械耳点后上方,散布于90°～150°范围内,距机械耳点最大垂直距离为15.1mm,最大水平距离9.0mm,平均向后2.3mm,向上8.9mm,平均距离9.2±3.89mm。结论:外耳道的解剖结构决定了解剖耳点与机械耳点的不一致。在临床中,要根据选择分析法的不同而选择相应的耳点。

Objective：To study the location relationship and assess the reason of the different location of mechanical Potion （Po-m）and anatomical Potion （Po-a）. Method：Lateral head films from 124 subjects with 42 males and 82 females whose average age was 11.3 years old were selected.Right-angled reference frame was build with the upside of Po-m as origin and FH plane as x-axis.The location relationship of Po-m and Po-a of all subjects was traced on one tracing paper. Result： 1.The rate of entire superposition of Po-m and Po-a was only 20.1%.2.There were four kinds of location relationship between Po-m and Po-a.3.Po-a often lies 2.3mm superior and 8.9mm C, posterior to Po-m. Conclusion-The different location of Po-m and Po-a was determined by the anatomical structure of outer earhole.It was concluded that corresponding Potion was selected based on different analytic methods.