上、下尖牙髓腔/牙体表面积比值的年龄判定价值研究

目的通过三维重建测量上、下颌尖牙髓腔/牙体表面积比值(Pulp/Tooth area Ratio,PTR)来推断个体年龄,为临床年龄推断的应用提供科学依据。方法收集口腔门诊患者年龄在16~65岁200例锥形束CT(Cone beam computed tomography,CBCT)影像资料,以4个尖牙为测量对象并进行三维重建,测量各尖牙髓腔和牙体表面积,计算PTR值。应用SPSS17.0软件进行统计学分析,推导实际年龄的推断公式。结果Pearson相关分析显示上、下颌尖牙PTR值与实际年龄呈高度负相关(P<0.001,r值为-0.833~-0.891)。4个尖牙间的PTR值无显著差异(P>0.05)。男女性别间尖牙PTR值无显著差异(P>0.05)。尖牙PTR值(x)推断年龄公式为:年龄=84.42-222.22x,R²=0.739。结论检测尖牙的PTR值,可明显提高临床年龄推断的准确性。

Age estimation by pulp cavity/tooth surface area ratio in maxillary and mandibular canines

Objective To estimate individual age by measuring the Pulp/Tooth area Ratio(PTR)of maxillary and mandibular canines by Cone-beam CT and 3 D reconstruction technique,so as to provide scientific basis for clinical age estimation.Methods The CBCT images of 200 subjects aged 16~65 years old were collected.Threedimensional reconstruction of four canines images was performed in each patient.The pulp cavity and tooth surface area of each canine were measured and the PTR ratio was calculated.SPSS17.0 was used for statistical analysis,and the inferential formula of actual age was deduced.Results Pearson’s correlation analysis showed that the ratio of maxillary and mandibular pulp cavity/tooth surface area was significantly negatively correlated with actual age(P<0.001),and the correlation coefficient r was between-0.833 and-0.891.There was no significant difference between the canine PTR values of maxillary and mandibular canines(P>0.05).There was no significant difference in the PTR value of canine between male and female(P>0.05).The age formula of canine PTR(x)was as follows:actual age=84.42-222.22 x,R²=0.739.Conclusions The PTR value of canines may significantly increase the accuracy of age estimation.