Anencephaly is the most severe form of a neural tube defect resulting from the incomplete occlusion of the anterior neuropore in the fourth week of development and associated with a severely underdeveloped brain mass. As desmal ossification of the neurocranium is induced by the presence of soft tissues (brain), no bone develops as direct consequence of the missing brain. The cranial base, by contrast, is formed by chondral ossification, which is genetically determined, and thus present also in anencephaly. Morphometric characteristics of anencephalic skulls, however, have not yet been investigated in sufficient detail before.

In this study we therefore comparatively assessed macroscopic morphological-anatomical and cephalometric CT data on structures and dimensions of 11 macerated anencephalic and 4 normal neonatal skulls highlighting skeletal morphological differences.

The most striking results were the missing skullcap and the greatly changed morphology of the existing skull bones, which were reduced in size. The parameters of the skull base, the transverse orbital diameter and maxillary width were significantly smaller in anencephalic skulls. The morphology of the viscerocranium appeared similar to that of normal neonatal skulls.

The results of this study can be used in diagnosis and skeletal classification for anencephaly. This can help identify bones that are incomplete, fragmented and taphonomically altered, which is often the case in historical and forensic studies.

无脑畸形是最严重的神经管缺陷形式，由发育第 4 周前神经孔不完全闭塞引起，并与严重发育不全的脑团有关。由于软组织（大脑）的存在会诱导神经颅骨的脱骨骨化，因此没有骨骼发育是大脑缺失的直接后果。相比之下，颅底是由软骨骨化形成的，这是遗传决定的，因此也存在于无脑畸形中。然而，之前还没有对无脑颅骨的形态特征进行足够详细的研究。

因此，在本研究中，我们比较评估了 11 个浸渍无脑颅骨和 4 个正常新生儿颅骨的结构和尺寸的宏观形态解剖学和头颅测量 CT 数据，突出了骨骼形态学差异。

最显着的结果是头骨消失了，现有头骨的形态发生了很大变化，体积缩小了。无脑颅骨的颅底、眶横径和上颌骨宽度参数明显较小。内脏颅骨的形态与正常新生儿颅骨的形态相似。

本研究结果可用于无脑畸形的诊断和骨骼分类。这有助于识别不完整、支离破碎和埋藏学改变的骨骼，这在历史和法医研究中经常出现。