北方汉族人Tanaka-Johnston预测方程研究

Tanaka-Johnston dentition analysis for northern Chinese

目的分析北方汉族青少年下颌切牙总宽度与尖牙、双尖牙总宽度之间的相关性,探寻适合目标人群的Tanaka-Johnston预测方程。方法从就诊于首都医科大学口腔医学院正畸科的病例中选取记存模型127副。研究下颌切牙总宽度与尖牙、双尖牙总宽度之间的相关性,建立北方汉族人的Tanaka-Johnston预测方程,并评价不同预测方程的准确性。结果男性组下颌切牙总宽度与上、下颌尖牙双尖牙总宽度之间相关系数r为0.71、0.77,女性组r为0.50、0.56。除本研究得出的方程外,其他预测方程普遍存在低估倾向。男性组实测值与预测值之差小于1mm的以北方汉族人方程上颌84%、下颌88%为最高;女性组以成都汉族人方程上颌74%,下颌81%为最高。结论与女性相比,男性下颌切牙总宽度与尖牙、双尖牙总宽度存在较强的正相关关系。预测准确度最高的方程分别为:男性上颌Y=11.8+0.5X,下颌Y=10.9+0.5X;女性上颌Y=11.1+0.5X,下颌Y=10.0+0.5X。

Objective To investigate the correlation between combined diameters of canines and premolars and lower incisors and to develop the prediction equation of Tanaka-Johnston for tooth size prediction in northern Chinese children. Methods A total of 127 northern Chinese were selected from 300 patients. Prediction equations of Tanaka and Johnston for northern Chinese were generated and the accuracy for different prediction equations was evaluated. Results The coefficients of correlation between combined diameters of canines and premolars and lower incisors were 0. 71 and 0. 77 in male, and 0. 50 and 0. 56 in female. The equations from other three studies tend to under-estimate the diameters of the permanent canines and premolars. For male, the highest proportion of evaluated error within lmm was 84% and 88% from the equations based on Northern Chinese, and for female was 74% and 81% from the equations based on Chengdu Chinese. Conclusion Correlations between combined diameters of canines and premolars and lower incisors for males were higher than those for females. The most accurate Tanaka-Johnston equations for northern Chinese were ： Y = 11.8 ＋ 0. 5X （maxilla for male） ; Y = 10. 9 ＋0. 5X （mandible for male） ; Y = 11.1 ＋0. 5X （maxilla for female） ; Y = 10. 0 ＋0. 5X （mandible for female）.