Micheletti Cremasco M
Dept. of Animal and Human Biology, University of Turin.
Boll Soc Ital Biol Sper. 1998 Mar-Apr;74(3-4):19-28.
The amount of sclerotic root dentine increases with age, proceeding from the apex towards the crown. There are obvious optical changes in the tissue, which becomes translucent (dentine is normally opaque). Therefore, the sclerosis of root dentine could be a reliable indicator of age in anthropological studies of human remains. We studied the histological aspects of sclerotic dentine in longitudinal thin sections (70-140 microns) of undecalcified premolars, cut in the bucco-lingual plane. To quantify the sclerosis and to construct a reference standard, we sectioned 85 premolars from subjects of known age (70 from odontological extractions and 15 from a university collection). Another 10 teeth from medieval subjects were studied to assess the applicability of the method to ancient skeletal collections. The technique consists of embedding the tooth in a polyester resin (cold method), sectioning it with a diamond blade microtome. Qualitative analysis was performed with polarized light microscopy and measurements were made with a quote 2D x,y viewer and on digital images. The sclerotic root dentine was quantified with both linear and surface area parameters in order to assess the correlation with age. The quality of the sections was sufficient for the clear discernment and quantification of the sclerotic dentine. Indeed, the technique allowed us to obtain good results with a considerable saving of time and money compared with other dental histological techniques. The best correlation with age was obtained from the surface area parameter, particularly after exclusion of the cementum and pulp chamber. To produce comparable data from similar studies, we advise the use of cold resins, as used here, and digital computerized analyzers because of their accuracy, precision and quickness. The qualitative analysis of the ancient teeth indications that this dental aging techniques can be applied to both recent and ancient dental tissues.
硬化根牙本质的量随年龄增长而增加，从根尖向牙冠方向发展。组织中存在明显的光学变化，其变得半透明（牙本质通常是不透明的）。因此，在对人类遗骸的人类学研究中，根牙本质的硬化可能是年龄的可靠指标。我们研究了在颊舌平面切割的未脱钙前磨牙纵向薄片（70 - 140微米）中硬化牙本质的组织学特征。为了量化硬化程度并构建参考标准，我们对已知年龄受试者的85颗前磨牙进行了切片（70颗来自牙科拔牙，15颗来自大学收藏）。还研究了另外10颗中世纪受试者的牙齿，以评估该方法对古代骨骼标本的适用性。该技术包括将牙齿嵌入聚酯树脂中（冷法），用金刚石刀片切片机进行切片。用偏光显微镜进行定性分析，并用二维x,y图像查看器和数字图像进行测量。用线性和表面积参数对硬化根牙本质进行量化，以评估与年龄的相关性。切片质量足以清晰辨别和量化硬化牙本质。事实上，与其他牙科组织学技术相比，该技术使我们能够在节省大量时间和金钱的情况下获得良好的结果。与年龄的最佳相关性来自表面积参数，特别是在排除牙骨质和牙髓腔之后。为了从类似研究中产生可比数据，我们建议使用此处使用的冷树脂和数字计算机分析仪，因为它们具有准确性、精确性和快速性。对古代牙齿的定性分析表明，这种牙齿老化技术可应用于近期和古代的牙齿组织。
