Department of Anatomy Catholic Institute of Applied Anatomy, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Division of Forensic Odontology and Disaster Oral Medicine, Department of Forensic Science, Iwate Medical University, Morioka, Iwate, Japan.
PLoS One. 2022 Jul 8;17(7):e0271247. doi: 10.1371/journal.pone.0271247. eCollection 2022.
This study aimed to validate Lee's age estimation method and assess the 18-year threshold in Korean and Japanese populations. We evaluated the maxillary and mandibular second (M2) and third molars (M3) in 2657 orthopantomograms of the Korean and Japanese populations aged 15-23 years (19.47±2.62 years for Koreans, 19.31±2.60 years for Japanese), using Demirjian's criteria. Dental age was estimated, and correlations between chronological and dental ages were analyzed. Classification performance was calculated based on the 18-year threshold. The relationship between developmental stage and chronologic age was analyzed using multiple linear regression. Our results revealed that Lee's method was appropriate for estimation in the Korean population. When the Lee's method was applied to the Japanese population, a lower value of correlation coefficients between estimated and chronological age, and lower specificity were observed. Population differences were observed predominantly in the stages of root development (stages F and G) of M2s and M3s in both jaws and more frequently in females than in males. In the multiple linear regression between developmental stage and chronological age, lower values of adjusted r2 were observed in the Japanese population than in the Koreans. In conclusion, the Lee's method derived from the Korean population data might be unsuitable for Japanese juveniles and adolescents. To support the findings of this study, future studies with samples from multiple institutions should be conducted. Future studies with larger sample sizes are also warranted to improve the accuracy of dental age estimation and confirm the developmental pattern of teeth in the Japanese population.
本研究旨在验证 Lee 法在韩国和日本人群中的适用性，并评估 18 岁年龄界限。我们评估了 2657 例年龄在 15-23 岁的韩国和日本人群的全景片（韩国人为 19.47±2.62 岁，日本人 19.31±2.60 岁），使用 Demirjian 标准评估牙龄，并分析了牙龄与实际年龄的相关性。基于 18 岁年龄界限，计算分类性能。使用多元线性回归分析发育阶段与实际年龄的关系。我们的结果表明，Lee 法适用于韩国人群的牙龄评估。当将 Lee 法应用于日本人群时，观察到估计牙龄与实际年龄之间的相关系数较低，特异性较低。在韩国和日本人群中，下颌和上颌第二磨牙（M2）和第三磨牙（M3）的根发育阶段（F 和 G 期）以及女性中观察到明显的人群差异。在发育阶段与实际年龄的多元线性回归中，日本人群的调整 r2 值低于韩国人群。总之，源于韩国人群数据的 Lee 法可能不适用于日本青少年。为支持本研究的发现，未来应开展来自多个机构的样本研究。未来还需要更大的样本量研究来提高牙龄评估的准确性，并确认日本人群牙齿的发育模式。
