经典的头影测量角度能否反映颌骨突度的实际变化

Inferring landmark displacements from changes in cephalometric angles

目的 讨论正畸临床常用的反映上下颌骨矢状位置的经典头影测量角度能否客观地反映上下颌骨突度的实际改变。方法 对 48例错患者治疗前后的头颅侧位片进行计算机头影测量 ,选择 3对反映上颌和下颌突度的角度及线距测量项目进行对比计数。结果 虽然角度测量与线距测量具有极显著意义的相关关系 ,但对比计数显示该 3对测量的不符合率分别达到 10 4%、2 2 9%和37 5 %。结论 单纯依据头影测量中的经典角度变化来评价上颌或下颌相对颅底的突度改变是不准确的。

Objective To investigate the appropriateness of using changes in angular measurements to r eflect the actually profile changes. Methods The sample consists of 48 growing malocclusion patients , contained 24 Class Ⅰ and 24 Class Ⅱ subjects, treated by an experienced orth odontist using Edgewise technique. Landmark and superimpositional data were extr acted from the previously prepared numerical database. Three pairs of angular an d linear measures were computed by the Craniofacial Software Package. Results Although the associations between all three angular mea sures and their corresponding linear measures are statistically significant at t he 0001 level, the disagreement between these three pairs of measures are 10 4%, 229% and 375% respectively in this sample. Conclusions The direction of displacement of anterior facial la ndmarks during growth and treatment cannot reliably be inferred merely from chan ges in cephalometric Angles.