Magri Stefano, Higgins Owen Alexander, Lugli Federico, Silvestrini Sara, Vazzana Antonino, Bondioli Luca, Nava Alessia, Benazzi Stefano
Department of Cultural Heritage, University of Bologna, Ravenna, Italy.
Department of Odontostomatological and Maxillo Facial Sciences, Sapienza University of Rome, Rome, Italy.
PLoS One. 2024 Dec 5;19(12):e0304051. doi: 10.1371/journal.pone.0304051. eCollection 2024.
Understanding the growth patterns and developmental trajectories of teeth during early life stages provides valuable insights into the ontogeny of individuals, particularly in archaeological populations where such information is scarce. This study focuses on first deciduous molars, specifically investigating crown formation times and daily secretion rates, through histological analysis. A total of 34 teeth from the Early Medieval necropolises of Casalmoro and Guidizzolo (Mantua, Lombardy, northern Italy) were analysed assessing growth parameters and identifying possible differences between sites and between sexes, which are determined through proteomic analysis. Furthermore, a robust linear regression model relating prism length and secretion time was built to estimate growth rates also in teeth in which the finest incremental markings are not visible. The daily secretion rates (DSR) in inner enamel showed a high homogeneity between dental arches, sexes and the two sites. Values fall within the known range reported in the literature for the same tooth class in archaeological populations. However, a difference in DSR was observed when compared with modern sample published values. Crown formation times and age at crown completion differ between dental arches, with maxillary first molars initiating their matrix apposition earlier than mandibular molars as formerly reported. However, no significant differences were highlighted in association with sex. This study expands our understanding of the growth and development of the first deciduous molars in a medieval population, providing valuable insights into growth trajectories specific to the dental arch. These findings highlight the need for extensive investigations using similar methodologies to attain more accurate and comprehensive information about the developmental patterns of first deciduous molars. Additionally, proteomic analysis improves the capability to conduct sex-specific histological assessments of immature individuals, thanks to this method's application in determining their sex.
了解牙齿在生命早期阶段的生长模式和发育轨迹，能为个体的个体发育提供有价值的见解，特别是在考古人群中，此类信息十分匮乏。本研究聚焦于第一乳磨牙，通过组织学分析具体研究牙冠形成时间和每日分泌率。对来自意大利北部伦巴第大区曼图亚的卡萨莫罗和圭迪佐洛早期中世纪墓地的34颗牙齿进行了分析，评估生长参数，并确定不同地点和不同性别之间可能存在的差异，这些差异通过蛋白质组学分析来确定。此外，建立了一个强大的线性回归模型，将棱柱长度与分泌时间相关联，以估计即使在最细微的增量标记不可见的牙齿中的生长速率。内釉质的每日分泌率（DSR）在牙弓、性别和两个地点之间表现出高度的同质性。数值落在考古人群中相同牙齿类别的文献报道的已知范围内。然而，与现代样本公布的值相比，观察到DSR存在差异。牙冠形成时间和牙冠完成时的年龄在牙弓之间存在差异，上颌第一磨牙开始基质附着的时间比下颌磨牙更早，正如之前所报道的那样。然而，未发现与性别相关的显著差异。本研究扩展了我们对中世纪人群中第一乳磨牙生长发育的理解，为特定牙弓的生长轨迹提供了有价值的见解。这些发现凸显了使用类似方法进行广泛研究的必要性，以获得关于第一乳磨牙发育模式更准确和全面的信息。此外，蛋白质组学分析提高了对未成熟个体进行性别特异性组织学评估的能力，这得益于该方法在确定其性别的应用。
