Size and placement of developing anterior teeth in immature Neanderthal mandibles from Dederiyeh Cave, Syria: implications for emergence of the modern human chin.
Size and placement of developing anterior teeth in immature Neanderthal mandibles from Dederiyeh Cave, Syria: implications for emergence of the modern human chin.
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叙利亚德德里耶洞穴中未成熟尼安德特人下颌骨发育中前牙的大小和位置：对现代人类下巴出现的影响。
DOI：
10.1002/ajpa.22665
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发表时间：
2015
影响因子：
2.8
通讯作者：
Ishida H
中科院分区：
文献类型：
--
作者：
Fukase H.;Kondo O.;Ishida H
人类下巴的进化和功能意义已经从不同的角度进行了探索，包括咀嚼生物力学，语音和前牙大小。最近的个体发育研究表明，内形成的前牙的空间位置部分限制成人下颌骨联合形态。因此，本研究初步研究了Dederiyeh 1和2的未成熟尼安德特人下颌骨中发育前牙的大小和位置，与年龄相似的现代人（N= 16）和黑猩猩（N= 7）进行了比较，后者的门牙在现存的原始人中分别相对较小和较大。Dederiyeh 1下颌骨被描述为略微呈现颏三角和伴随的颏窝，而Dederiyeh 2完全缺乏这种下巴相关的构型。结果表明，尽管联合的大小是在现代人类的范围内，Dederiyeh下颌骨容纳整体较大的前牙列，并显示出显着广泛的双齿间隙相比，现代人类。Dederiyeh 2有相对较厚的乳牙牙根和更扩大的恒切牙隐窝比Dederiyeh 1，但这两个Dederiyeh个人表现出的总牙齿大小主要是现代人类和黑猩猩之间的中间。这些发现可能意味着大的乳牙/恒切牙共同扩张了唇侧牙槽骨，掩盖了早期的颏三角。因此，假设下巴相关特征的出现，特别是颏三角和颏窝的出现，可以部分地由下颌可用空间和前牙的大小之间的发育关系来解释。然而，这一假设必须在未来的研究中进一步解决更多的参考样本。美国物理人类学杂志156：482-488，2015年。© 2014 Wiley Periodicals，Inc.
Evolutionary and functional significance of the human chin has long been explored from various perspectives including masticatory biomechanics, speech, and anterior tooth size. Recent ontogenetic studies have indicated that the spatial position of internally forming anterior teeth partially constrains adult mandibular symphyseal morphology. The present study therefore preliminarily examined the size and placement of developing anterior teeth in immature Neanderthal mandibles of Dederiyeh 1 and 2, compared with similarly‐aged modern humans (N= 16) and chimpanzees (N= 7) whose incisors are comparatively small and large among extant hominids, respectively. The Dederiyeh 1 mandible is described as slightly presenting a mental trigone and attendant mental fossa, whereas Dederiyeh 2 completely lacks such chin‐associated configurations. Results showed that, despite symphyseal size being within the modern human range, both Dederiyeh mandibles accommodated overall larger anterior dentition and displayed a remarkably wide bicanine space compared to those of modern humans. Dederiyeh 2 had comparatively thicker deciduous incisor roots and more enlarged permanent incisor crypts than Dederiyeh 1, but both Dederiyeh individuals exhibited a total dental size mostly intermediate between modern humans and chimpanzees. These findings potentially imply that the large deciduous/permanent incisors collectively distended the labial alveolar bone, obscuring an incipient mental trigone. It is therefore hypothesized that the appearance of chin‐associated features, particularly of the mental trigone and fossa, can be accounted for partly by developmental relationships between the sizes of the available mandibular space and anterior teeth. This hypothesis must be, however, further addressed with more referential samples in future studies. Am J Phys Anthropol 156:482–488, 2015. © 2014 Wiley Periodicals, Inc.