Kotze Daniël, Mole Calvin G, Phillips Vincent M, Gibbon Victoria E
Division of Clinical Anatomy and Biological Anthropology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Private Bag X3, Observatory, Cape Town, 7935, South Africa.
Division of Forensic Medicine and Toxicology, Department of Pathology, University of Cape Town, Cape Town, South Africa.
Int J Legal Med. 2025 Mar;139(2):887-899. doi: 10.1007/s00414-024-03360-7. Epub 2024 Nov 1.
Age-at-death estimation is pivotal in the identification of unknown human decedents in forensic medicine. The pulp/tooth area ratio (PAR) method, assessing pulp cavity size as a marker of secondary dentine apposition, is widely utilised for adult age estimation. Despite extensive evaluation of this technique, the influence of image type and enamel area inclusion on method accuracy is insufficiently explored. The present study evaluated the PAR method's applicability using maxillary canines from a South African cadaveric sample, examining reliability, sex bias, and accuracy across different image types and enamel area considerations. An observational, cross-sectional study design was followed. Fifty-two adult maxillary canines were radiographed, sectioned, and analysed using stereomicroscopy. Labiolingual and mesiodistal periapical radiographs, alongside labiolingual stereomicroscopic tooth section images, were analysed using ImageJ to calculate PARs. Age estimation linear regression models were developed for each image type, with and without enamel area inclusion. Models were compared for performance and accuracy using best-subsets regression and cross-validation analyses. Results indicated that the PAR method is a reliable, sex-independent technique, providing relatively accurate age-at-death estimates for South African adults. Image type significantly influenced accuracy, with tooth section images exhibiting the best/lowest error values, followed by labiolingual and mesiodistal radiographs, respectively. Exclusion of enamel area consistently enhanced model performance across all image types. This study contributes valuable data to the underexplored field of dental age estimation techniques for South African adults, highlighting optimal approaches when applying the PAR method to maxillary canines. Additionally, it introduces a refined stereomicroscopic technique, augmenting and enhancing existing practices.
死亡年龄估计在法医学中识别不明身份的人类死者方面至关重要。牙髓/牙面积比（PAR）方法通过评估牙髓腔大小作为继发性牙本质沉积的标志，被广泛用于成人年龄估计。尽管对该技术进行了广泛评估，但图像类型和釉质面积纳入对方法准确性的影响尚未得到充分探索。本研究使用来自南非尸体样本的上颌尖牙评估了PAR方法的适用性，研究了不同图像类型和釉质面积考量下的可靠性、性别偏差和准确性。采用了观察性横断面研究设计。对52颗成人上颌尖牙进行了放射照相、切片，并使用体视显微镜进行分析。使用ImageJ分析唇舌向和近远中根尖片以及唇舌向体视显微镜牙齿切片图像，以计算PAR值。针对每种图像类型，分别建立了包含和不包含釉质面积的年龄估计线性回归模型。使用最佳子集回归和交叉验证分析对模型的性能和准确性进行比较。结果表明，PAR方法是一种可靠的、与性别无关的技术，可为南非成年人提供相对准确的死亡年龄估计。图像类型对准确性有显著影响，牙齿切片图像的误差值最佳/最低，其次分别是唇舌向和近远中根尖片。排除釉质面积在所有图像类型中均持续提高了模型性能。本研究为南非成年人牙齿年龄估计技术这一未充分探索的领域提供了有价值的数据，突出了将PAR方法应用于上颌尖牙时的最佳方法。此外，它还引入了一种改进的体视显微镜技术，增强并完善了现有做法。
