Someda H, Saka H, Matsunaga S, Ide Y, Nakahara K, Hirata S, Hashimoto M
Department of Anatomy, Tokyo Dental College, Chiba, Japan.
Forensic Sci Int. 2009 Mar 10;185(1-3):110-4. doi: 10.1016/j.forsciint.2009.01.001. Epub 2009 Feb 7.
The purpose of this study was to investigate an age estimation method that considers gender as well as three-dimensional measurement of the components, specifically enamel and dentin. A total of 155 mandibular central incisors aged 12-79 years old which was chosen from the collection stored at the Department of Anatomy in Tokyo Dental College and had no opened apex, caries or restorative treatment, were examined. Samples were scanned using micro-CT HMX225 ACTIS4. Based on the sliced image data, three-dimensional structures were obtained and the volumes of enamel, dentin, and pulp cavity were measured. Regression equations for age estimation were then determined. The accuracy of age estimation equations for each region, volume ratio, and sex was assessed using the determination coefficient R(2) as well as the standard errors of estimated values. The root region alone had a comparable accuracy to that of the whole tooth and the crown region had a relatively lower accuracy. In the whole tooth and the crown region, slightly higher correlations were observed for pulp/tooth volume ratios in which enamel was excluded. Females tended to have higher accuracy compared to males. The estimated age was higher in males compared to females for the same volume ratio of the pulp cavity. The highest correlation in both genders with age was observed for the volume ratio of the pulp cavity to the whole tooth excluding the enamel (males, R(2)=0.67; females, R(2)=0.76). The 95% confidence intervals for the population regression showed different distributions for each sex. In the 95% prediction intervals for age estimation, females tended to have narrower intervals and higher accuracy compared to males. Therefore, the use of gender-specific equations is recommended for age estimation.
本研究的目的是探究一种年龄估计方法，该方法将性别以及牙体各组成部分（特别是牙釉质和牙本质）的三维测量考虑在内。从东京齿科大学解剖学系保存的标本中选取了155颗年龄在12至79岁之间的下颌中切牙，这些牙齿根尖未开放、无龋坏或修复治疗史，并对其进行了检查。使用微CT HMX225 ACTIS4对样本进行扫描。基于断层图像数据，获取三维结构并测量牙釉质、牙本质和牙髓腔的体积。然后确定年龄估计的回归方程。使用决定系数R²以及估计值的标准误差评估每个区域、体积比和性别的年龄估计方程的准确性。仅牙根区域的准确性与整个牙齿相当，而牙冠区域的准确性相对较低。在整个牙齿和牙冠区域，排除牙釉质后的牙髓/牙齿体积比的相关性略高。女性的准确性往往高于男性。对于相同的牙髓腔体积比，男性的估计年龄高于女性。在排除牙釉质后的牙髓腔与整个牙齿的体积比方面，男女与年龄的相关性最高（男性，R² = 0.67；女性，R² = 0.76）。总体回归的95%置信区间显示男女分布不同。在年龄估计的95%预测区间内，女性的区间往往比男性更窄，准确性更高。因此，建议使用特定性别的方程进行年龄估计。
