Charles D K, Condon K, Cheverud J M, Buikstra J E
Am J Phys Anthropol. 1986 Nov;71(3):311-20. doi: 10.1002/ajpa.1330710306.
In order to test the feasibility of cementum annulations to estimate age in humans, observer error and tooth variability in cementum ring counts were evaluated in a sample of 42 mandibular canine and first premolar pairs. Additionally, two sectioning techniques were evaluated. Demineralized thin sections (7 micron) stained with hematoxylin are the preferred technique since their age related variance is greater than 75% for all tooth types examined. In contrast, less than 50% of the total variance was accounted for among individuals when mineralized sections (80 micron) stained with alizarin red were used. Intertooth variability in ring counts of demineralized sections was large between canines and premolars (43%). Premolars provide counts with lower interobserver error and are the preferred tooth. In an expanded sample (N = 51) of demineralized premolars, intraobserver and interobserver error accounted for 2% and 5% of the total variance, respectively. Evaluation of several experimental designs showed that increasing the number of slides per tooth has the greatest effect on reducing variance followed by increasing the number of observers. Increasing the number of observations has little effect. Cementum ring counts are measurable to a highly repeatable extent and provide a level of repeatability greater than that reported for the pubic symphysis and auricular surface aging techniques.
为了测试牙骨质年轮用于估计人类年龄的可行性，在一个包含42对下颌犬齿和第一前磨牙的样本中，评估了牙骨质环计数中的观察者误差和牙齿变异性。此外，还评估了两种切片技术。用苏木精染色的脱矿薄切片（7微米）是首选技术，因为在所检查的所有牙齿类型中，其与年龄相关的方差大于75%。相比之下，当使用茜素红染色的矿化切片（80微米）时，个体间的总方差不到50%。脱矿切片的环计数在犬齿和前磨牙之间的牙齿间变异性很大（43%）。前磨牙提供的计数观察者间误差较低，是首选牙齿。在一个扩大的脱矿前磨牙样本（N = 51）中，观察者内误差和观察者间误差分别占总方差的2%和5%。对几种实验设计的评估表明，增加每颗牙齿的切片数量对减少方差的影响最大，其次是增加观察者数量。增加观察次数的影响很小。牙骨质环计数在高度可重复的程度上是可测量的，并且提供了比耻骨联合和耳郭表面老化技术所报告的更高的重复性水平。
