牙构造与年龄的关系——第一磨牙内部构造与年龄的关系

本文根据牙本质终身不断地向髓腔方面增生的生理现象,对我国华南地区97颗上颌第一磨牙进行了研究。在研究中应用显微测量技术,在按统一标准制成的牙磨片上测量有关项目,依据指数公式求出髓室牙本质指数。研究结果表明,髓室牙本质指数与年龄的变化呈负相关关系。本文求出了用指数推算年龄的回归方程,并列出了可供参考的年龄估计值全体均数的95％可信限表。

THE RELATIONSHIP BETWEEN THE CONSTRUCTION OF MAXILLARY FIRST MOLAR AND AGE

97 maxillary first permanent molars of Southern Chinese were investigated in this report. The method of study is as follows: the teeth investigated were ground into 0.5 mm thick slics through the central part of the buccolingual sides of the molar. The height and width of the pulp chamber and the dentine of the slice were measured with the micrometer through microscope. The pulp-dentine index was calculated according to the following formula: Pulp-dentine index=(height width of pulp chamber)/height width of dentinexxxxxxxxxxx100 We found that there is a negative correlation between the pulp-dentine index and the age of all teeth examined. The regression formula to estmate age is: y=(-1.01))x 82.82 (where: y=pulp-dentine index, x=estimated age).