Methods : we have divided the 636 molars ( without dental caries or pathological changes of root ) collected in school of forensic medicine and stomatological hospital in shanxi medicine university into four groups : maxl , max2 , manl , man2 , and selected 5 indexes closely related to changes of dental age ( dental attrition , contact area , the index of dentine marrow cavity , the thickness of cementum of root , the diaphaneity of dentine of root ) , and proposed the grading standard and scoring standard date processing and statistical analysis after measuring the teeth of the four groups 方法：从山西医科大学法医学院及口腔医院收集的636磨牙(无龋坏、无根尖病变)分为max1 、 max2 、 man1 、 man2四组，根据牙齿的增龄变化特点，筛选了5个与牙龄变化密切相关的指标(牙齿的磨耗、接触区面积、牙本质髓室指数、根尖牙骨质的厚度、根尖牙本质透明) ，提出了指标的分级标准和评分标准，对各组的牙齿测量后进行数据处理和统计分析。
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Results : all the five indexes ( dental attrition , contact area , the index of dentine marrow cavity , the thickness of cementum of root , the diaphaneity of dentine of root ) revealed a highly interrelated relationship with age . regression height was significant when the multiple regression equation , which was formulated with these five indexes and age and used to judge the age was statistically analyzed 结果：牙齿的磨耗、接触区面积、牙本质髓室指数、根尖牙骨质的厚度、根尖牙本质透明均反映出与年龄高度相关关系，用这5个指标与年龄所建立的判别年龄的多元回归方程经统计学分析，回归高度显著。
