中国汉族人鼻背长轴与下颌生长方向的相关性研究

The correlations between nasal dorsum axis and mandibular growth direction in Chinese individuals

目的:分析鼻背生长方向与下颌生长方向的相关性。方法:随机选取311例成人正畸患者,收集其治疗前头影测量片,测量Y轴角、背长轴角,分析二者的相关性。计算代表这两个角度差异性的鼻背旋角,并分析影响鼻背旋角的因素。结果:Y轴角与鼻背长轴角有相关性(相关系数r=0.489,P=0004)。鼻背旋角的均值为2.25°±3.89°,95%可信区间为(1.82°,2.70°)。鼻背旋角与性别无明显相关性,但是与矢状骨型具有明显的相关性,即骨性I类患者的鼻背长轴角与Y轴角较接近,骨性II类患者的Y轴相对于鼻背长轴要偏后下旋转,骨性III类患者的Y轴相对于鼻背长轴则出现前上旋转倾向。随着矢状骨型由III类到I类、再到II类,其Y轴角逐渐增大(P<0.01),而不同矢状骨型患者的鼻背长轴角间未见明显差异(P>0.05)。结论:鼻背长轴与Y轴接近平行,且有一定的正相关性。不同矢状骨型患者间鼻背旋角的差异机制并不在于鼻背生长方向的不同,而在于下颌生长方向的不同。

Objective：To analyze the correlations between the growth directions of mandibular and the nasal dorsum axis.Methods：311adult orthodontic patients were chosen randomly.The lateral cephalograms of these patients before treatment were collected.Y axis angle and dorsum axis angle were measured and the correlations between them were analyzed.The dorsum swing angle which represented the difference between these two angles was calculated,and the influencing cranialfacial factors were analyzed.Results：The correlations between Y axis angle and dorsum axis angle were suggested（r=0.489,P =0004）.The mean of the dorsum swing angle was 2.25°±3.89°,and 95%confidence interal was（1.82°,2.70°）.The dorsum swing angle was not correlative with sex significantly,but it was correlative significantly with the anteroposterior relationship between upper and lower jaws.Y axis angle and dorsum axis angle in class I patients were nearly equal.Compared with the Y axis,the dorsum axis changed downward and backward in class III patients with opposite change in class II patients.As the anteroposterior skeletal pattern changed from class III to I,then to II,the Y axis angle increased（P〈0.01）,whereas there was no significant change in the dorsum axis angle（P〉0.05）.Conclusions：Y axis angle had positive correlation with the dorsal axis angle,and they were approximate parallel.The differences of dorsum swing angles among different anteroposterior patients might result from the differences of growth directions of mandibular instead of the differences of growth directions of nasal dorsum.