Jawad Salam N, Alwan Safa H
College of Dentistry, Bilad Alrafidain University, Baqubah, IRQ.
College of Dentistry, Al-Farahidi University, Baghdad, IRQ.
Cureus. 2025 Aug 2;17(8):e89236. doi: 10.7759/cureus.89236. eCollection 2025 Aug.
This retrospective cross-sectional study evaluates the effectiveness of using the pulp/tooth area ratio of mandibular second molars for identifying minors (<18 years) in an Iraqi population and compares its diagnostic performance to the third molar root completion status.
A total of 216 panoramic radiographs were analyzed. Pulp/tooth area ratios were measured using ImageJ (National Institutes of Health, Bethesda, MD), and third molar root completion was recorded as a binary variable. Three logistic regression models were constructed and evaluated using sensitivity, specificity, and area under the ROC curve (AUC).
Incomplete third molar root development showed high sensitivity (0.90), while the second molar pulp/tooth ratio demonstrated superior specificity (0.99). The combined model (ratio + third molar) yielded the highest overall performance (AUC = 0.96), outperforming individual predictors (third molar only: AUC = 0.90; ratio only: AUC = 0.84).
While the pulp/tooth ratio alone is less sensitive, it provides excellent specificity and enhances overall model performance when combined with third molar status. These findings support the combined use of both variables for accurate age estimation in forensic settings lacking reliable documentation.
这项回顾性横断面研究评估了利用下颌第二磨牙的髓腔/牙体面积比来识别伊拉克人群中未成年人（<18岁）的有效性，并将其诊断性能与第三磨牙牙根发育完成情况进行比较。
共分析了216张全景X线片。使用ImageJ（美国国立卫生研究院，马里兰州贝塞斯达）测量髓腔/牙体面积比，并将第三磨牙牙根发育完成情况记录为二元变量。构建了三个逻辑回归模型，并使用敏感性、特异性和ROC曲线下面积（AUC）进行评估。
第三磨牙牙根发育不完全显示出高敏感性（0.90），而第二磨牙髓腔/牙体比显示出更高的特异性（0.99）。联合模型（比值+第三磨牙）产生了最高的总体性能（AUC = 0.96），优于单个预测指标（仅第三磨牙：AUC = 0.90；仅比值：AUC = 0.84）。
虽然单独的髓腔/牙体比敏感性较低，但它具有出色的特异性，并且与第三磨牙状态联合使用时可提高总体模型性能。这些发现支持在缺乏可靠文件的法医环境中联合使用这两个变量进行准确的年龄估计。
