Bastir Markus, Rosas Antonio, O'higgins Paul
Hull York Medical School, The University of York, Heslington, York, UK.
J Anat. 2006 Nov;209(5):637-54. doi: 10.1111/j.1469-7580.2006.00644.x.
It is well known that the human skull achieves adult size through a superior-inferior gradient of maturation. Because the basicranium matures in size before the face, it has been suggested that the form of the basicranium might have ontogenetic knock-on effects on that of the face. However, although sequential spatially organized maturation of size is well described in the cranium, the maturation of skull shape is not. Knowledge of the maturation of shape is important, nevertheless, because it is claimed that the early determination of the spatial configuration of basicranial components, where the facial skeleton attaches, is relevant in the spatio-temporal ontogenetic cascade from basicranium to face. This paper examines the ontogeny of various components of the human skull in 28 individuals from the longitudinal Denver Growth Study. Sixty-six landmarks and semilandmarks were digitized on 228 X-rays and analysed using geometric morphometric methods. Bootstrapped confidence intervals for centroid size support previous studies suggesting a supero-inferior gradient of growth maturation (size over time), while developmental maturation (shape over time) is more complex. A sequence of shape maturation is described, in which the earliest structure to mature in shape was the midline cranial base (7-8 years), followed by the lateral cranial floor (11-12), midline neurocranium (9-10) and facial and mandibular structures (15-16). The absolute ages of shape maturation of the latter three depended on the criterion of maturity used, which was not the case for the basicranial components. Additionally, ontogenetic dissociations were found between the maturation of size and shape of the midline cranial base and lateral floor, possibly underlining its role as structural 'interface' between brain and facial ontogeny. These findings imply potential for bidirectional developmental influences between the lateral cranial floor and the face until about 11-12 years. The findings are discussed with regard to their relevance for palaeoanthropology and especially the evolutionary and developmental bases of skull morphological variation.
众所周知,人类头骨通过上下成熟梯度达到成人大小。由于颅底在面部之前成熟,有人提出颅底的形态可能对面部形态有个体发育的连锁效应。然而,尽管颅骨大小的顺序性空间组织成熟已有很好的描述,但颅骨形状的成熟情况却并非如此。然而,形状成熟的知识很重要,因为据称面部骨骼附着的颅底成分空间构型的早期确定与从颅底到面部的时空个体发育级联相关。本文研究了来自丹佛纵向生长研究的28名个体的人类头骨各组成部分的个体发育。在228张X光片上对66个地标和半地标进行数字化处理,并使用几何形态计量学方法进行分析。质心大小的自举置信区间支持了先前的研究,表明生长成熟存在上下梯度(随时间的大小),而发育成熟(随时间的形状)则更为复杂。描述了形状成熟的顺序,其中最早形状成熟的结构是中线颅底(7 - 8岁),其次是外侧颅底(11 - 12岁)、中线脑颅(9 - 10岁)以及面部和下颌结构(15 - 16岁)。后三者形状成熟的绝对年龄取决于所使用的成熟标准,而颅底成分并非如此。此外,在中线颅底和外侧颅底的大小和形状成熟之间发现了个体发育解离,这可能凸显了其作为脑和面部个体发育之间结构“界面”的作用。这些发现意味着直到大约11 - 12岁,外侧颅底和面部之间存在双向发育影响的潜力。本文讨论了这些发现与古人类学的相关性,特别是头骨形态变异的进化和发育基础。