Exploring the biomechanics of taurodontism
Exploring the biomechanics of taurodontism
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DOI：
10.1111/joa.12260
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发表时间：
2015-02-01
影响因子：
2.4
通讯作者：
Hublin, Jean-Jacques
中科院分区：
文献类型：
--
作者：
Benazzi, Stefano;Nguyen, Huynh N.;Hublin, Jean-Jacques
牛齿症（即髓腔扩大，伴随着牙根分叉/三叉的根尖移位）被认为是一种在当代社会中发病率相对较低的牙齿异常，但它代表了尼安德特人牙齿中常见的典型特征。可以设想四种假设来解释尼安德特人的高频率：适应特定的咬合负荷制度（生物力学优势），适应高摩擦饮食，多效性或遗传漂移效应。在这篇文章中，我们使用有限元分析（FEA）和先进的加载概念的基础上，宏观磨损信息，以评估牛牙是否提供一些牙齿生物力学的优势。将载荷施加到尼安德特人样本Le Moustier 1的右下第一磨牙（RM 1）的数字模型，以及Le Moustier RM 1的缩短和超牛磺酸版本的数字模型。此外，我们模拟了一个场景，一个物体被夹在牙齿之间，并在不同的方向上拉，以调查牛齿畸形是否可能是有用的辅助咀嚼活动。我们的研究结果并没有显示出任何有意义的差异之间的所有模拟，指出，牛齿症并没有改善牙齿的功能生物力学，并不有利于副咀嚼拉活动。因此，牛齿症应被认为是对高消耗饮食的适应，或者很可能是多效性或遗传漂变效应的结果。最后，我们的研究结果在牙髓治疗过程中对现代牙科有重要意义，因为我们观察到用牙本质样材料填充髓室会增加牙齿刚度，并最终增加牙冠中的拉伸应力，从而有利于牙齿失效。
Taurodontism (i.e. enlarged pulp chamber with concomitant apical displacement of the root bi/trifurcation) is considered a dental anomaly with relatively low incidence in contemporary societies, but it represents a typical trait frequently found in Neandertal teeth. Four hypotheses can be envisioned to explain the high frequency in Neandertals: adaptation to a specific occlusal loading regime (biomechanical advantage), adaptation to a high attrition diet, pleiotropic or genetic drift effects. In this contribution we used finite element analysis (FEA) and advanced loading concepts based on macrowear information to evaluate whether taurodontism supplies some dental biomechanical advantages. Loads were applied to the digital model of the lower right first molar (RM1) of the Neandertal specimen Le Moustier 1, as well as to the digital models of both a shortened and a hyper-taurodontic version of Le Moustier RM1. Moreover, we simulated a scenario where an object is held between teeth and pulled in different directions to investigate whether taurodontism might be useful for para-masticatory activities. Our results do not show any meaningful difference among all the simulations, pointing out that taurodontism does not improve the functional biomechanics of the tooth and does not favour para-masticatory pulling activities. Therefore, taurodontism should be considered either an adaptation to a high attrition diet or most likely the result of pleiotropic or genetic drift effects. Finally, our results have important implications for modern dentistry during endodontic treatments, as we observed that filling the pulp chamber with dentine-like material increases tooth stiffness, and ultimately tensile stresses in the crown, thus favouring tooth failure.