对穿孔性中耳炎患者咽鼓管功能的测定,20多年来多沿用Miller的五级分类法,即:借吞咽动作能完全消除鼓室负压的为Ⅰ级;吞咽后尚残留1～50mmH_2O负压的为Ⅱ级;残留50mmH_2O以上负压的为Ⅲ级;如吞咽动作只能消除鼓室正压,则为Ⅳ级;如对鼓室正压和负压都不起作用,则属Ⅴ级。但有人曾指出只要吞咽后残余鼓室正压<30mmH_2O,就适于鼓 Eustachian tube function in patients with perforation of the otitis media more than 20 years to follow Miller’s five-stage classification, that is: by swallowing to completely eliminate the negative pressure of the tympanum for the class; still swallowed 1 ~ 50mmH2O negative pressure Ⅱ grade; residual negative pressure above 50mmH_2O grade Ⅲ; such as swallowing can only eliminate tympanum positive pressure, then grade Ⅳ; if the positive and negative tympanic pressure is ineffective, it is grade Ⅴ. However, it has been pointed out that as long as the residual tympanic pressure after swallowing <30mmH_2O, it is suitable for the drum