Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia.
Adelaide Dental School, University of Adelaide, Adelaide, South Australia, Australia.
Am J Phys Anthropol. 2021 Feb;174(2):375-383. doi: 10.1002/ajpa.24120. Epub 2020 Aug 10.
Carabelli is a nonmetric dental trait variably expressed as a small pit to a prominent cusp in the maxillary molars of modern humans. Investigations on the occurrence and expression rates of this trait have been conducted extensively, tracing its origin to genetic sources. However, there remains a lack of understanding about its potential role in chewing. In this study, we examine molar macrowear with the aim of reconstructing Carabelli trait occlusal dynamics occurring during chewing.
We have examined 96 deciduous and permanent maxillary molars of children and young adults from Yuendumu, an Australian Aboriginal population that was at an early stage of transition from a nomadic and hunter-gatherer way of life to a more settled existence. We apply a well-established method, called Occlusal Fingerprint Analysis, which is a digital approach for analyzing dental macrowear allowing the reconstruction of jaw movements required to produce wear pattern specific to each tooth.
Carabelli trait slightly enlarges the surface functional area, especially in those molars where this feature is expressed in its cuspal form and it is closer to the occlusal plane. Moreover, the highly steep contact planes would also indicate that Carabelli wear areas contribute to increasing the shearing abilities of the occluded teeth, which are particularly important when processing fibrous and tough foods.
The macrowear analysis suggests that Carabelli trait in the Aboriginal people from Yuendumu slightly enhanced occlusion and probably played some functional role during mastication. Future biomechanical and microwear analyses could provide additional information on the mechanical adaptation of Carabelli trait in modern human dentition.
卡巴利（Carabelli）是一种非度量性牙齿特征，在上颌磨牙中表现为从小的凹陷到明显的尖峰不等。对这种特征的发生和表达率的研究已经广泛开展，追溯其起源于遗传来源。然而，对于其在咀嚼中的潜在作用仍缺乏了解。在本研究中，我们检查了磨牙的宏观磨损，旨在重建卡巴利特征在咀嚼过程中的咬合动力学。
我们检查了来自于尤伦杜姆（Yuendumu）的 96 颗儿童和年轻成人的上颌恒磨牙和乳磨牙，这是一个澳大利亚原住民群体，正处于从游牧和狩猎采集生活方式向更加定居生活方式转变的早期阶段。我们应用了一种成熟的方法，称为咬合指纹分析（Occlusal Fingerprint Analysis），这是一种用于分析牙齿宏观磨损的数字方法，可以重建产生特定于每个牙齿的磨损模式所需的颌骨运动。
卡巴利特征略微增大了表面功能区域，特别是在那些以尖峰形式表现出该特征的磨牙中，并且更接近咬合平面。此外，高度陡峭的接触平面也表明卡巴利磨损区域有助于增加咬合牙齿的剪切能力，这在处理纤维状和坚韧食物时尤为重要。
宏观磨损分析表明，尤伦杜姆原住民的卡巴利特征略微增强了咬合，并在咀嚼过程中可能发挥了一些功能作用。未来的生物力学和微观磨损分析可以提供有关现代人类牙齿中卡巴利特征的机械适应性的更多信息。
