Laboratory of Personal Identification and Forensic Morphology, Department of Health Sciences, University of Florence, Florence, Italy.
Research Group in Forensic Dental Sciences FORENSEMED from the Research Unit UICOB, Faculty of Dental Medicine, University of Lisbon, Portugal.
J Forensic Odontostomatol. 2024 Aug 29;42(2):60-75. doi: 10.5281/zenodo.13371720.
Estimating the post-mortem interval (PMI) of human remains based on the histomorphology of dental pulp parameters is promising, but available evidence is scarce and sometimes contradictory without a scientific model. The aim of the study is to characterise the histomorphological changes of dental pulp associated with the decomposition of human remains by a qualitative and quantitative approach. The main aim is to establish a correlation based on post-mortem (PM) dental pulp histomorphology and the PMI, and whether pulp degradation could be an available medico-legal tool for PMI estimation beyond the first week after death (late PMI). The eligible sample consisted of 27 sound teeth from 16 healthy patients aged 16 to 72 years due to orthodontic or oral surgery treatment, to create PMI's simulating the death of the subject as the time elapsed from tooth avulsion. Data collected from patients (sex, date of birth, tooth position, date and hour of the avulsion, date and hour of pulp extraction) were anonymised in accordance with the requirements of Faculty of Dental Medicine of the University of Lisbon. The sample was divided into 9 groups of 3 teeth according to different PMI sets from T0 (baseline) up to 2 weeks (T0, 7, 12, 24, 36, 48, and 72 hours, 1 and 2 weeks). All the dental samples were stored at room temperature up to the time of pulp extraction and then prepared with haematoxylin and eosin stain. High-resolution microscopy was performed to obtain histological images. An operator performed the qualitative evaluation of blood vessels, collagen fibres, and the extra-cellular matrix (ECM) in PM pulps and measured the variation in cells/nuclei density by counting 6 different ROIs (Regions of Interest) for each pulp manually and automatically (quantitative analysis). Qualitative results showed that the degeneration of dental pulp appears 7 hours after death but histological changes in vessels, fibres, and ECM in PM dental pulp are characterised by high variability, consequently it is not possible to generalise the results for early PMIs. Quantitative measurements proved that cell count cannot be standardised due to the presence of superimposed layers of cells and nuclei fragmentation. Odontoblasts did not demonstrate evidence of cellular or nuclear lysis up to 14 PM suggesting their applicability in late PMIs. Future research will focus on late PMIs and different techniques of tooth preparation.
基于牙髓参数的组织形态学来估计人类遗骸的死后间隔时间（PMI）是有前途的，但目前的证据很少，而且没有科学模型时有时相互矛盾。本研究的目的是通过定性和定量的方法来描述与人类遗骸分解相关的牙髓组织形态学变化。主要目的是基于死后（PM）牙髓组织形态学和 PMI 建立相关性，以及牙髓降解是否可以成为一种可用的法医学工具，用于估计死后第一周后（晚期 PMI）的 PMI。合格的样本由 16 名年龄在 16 至 72 岁之间的健康患者的 27 颗健康牙齿组成，这些牙齿是由于正畸或口腔手术治疗而拔除的，以模拟受试者的 PMI，从拔牙时开始计算。根据里斯本大学牙医学院的要求，对从患者收集的数据（性别、出生日期、牙齿位置、拔牙日期和时间、牙髓提取日期和时间）进行了匿名处理。该样本根据从 T0（基线）到 2 周（T0、7、12、24、36、48 和 72 小时、1 周和 2 周）的不同 PMI 集分为 9 组，每组 3 颗牙齿。所有牙髓样本均在室温下保存至牙髓提取时间，然后用苏木精和伊红染色进行制备。进行高分辨率显微镜检查以获得组织学图像。一名操作员对 PM 牙髓中的血管、胶原纤维和细胞外基质（ECM）进行定性评估，并通过手动和自动计数（定量分析）对每个牙髓的 6 个不同 ROI（感兴趣区域）进行细胞/核密度的变化测量。定性结果表明，死后 7 小时牙髓开始退化，但 PM 牙髓中血管、纤维和 ECM 的组织学变化具有高度可变性，因此不可能对早期 PMI 进行概括。定量测量结果表明，由于细胞和核碎片的叠加层的存在，细胞计数不能标准化。在 14 PM 时，成牙本质细胞没有表现出细胞或核溶解的证据，这表明它们在晚期 PMI 中的适用性。未来的研究将集中在晚期 PMI 和不同的牙齿准备技术上。
