Kimura S, Schaumann B
First Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan.
Anat Rec. 1988 Sep;222(1):83-9. doi: 10.1002/ar.1092220112.
A study of the embryological development and morphology of the thumb flexion creases is presented. We used 178 human fetuses, at 6-20 weeks of gestational age, and 225 normal adults, aged 19-81 years, to observe the morphology and the timing and location of the appearance of the flexion creases. Most creases, that is, the regular, extra, and oblique creases, were found to develop concurrently with the appearance of the fetal volar pads, apparently independently of the thumb flexion movements. Although the regular creases usually appear to be simple, single creases, they seem to be formed by the radial and ulnar lateral crease segments that develop inwards from each lateral side. Our observations also suggest that the oblique and extra creases on the proximal phalanx of the thumb should be considered as common or "regular" creases, rather than anomalies, because of their high frequency in fetuses and in normal healthy adults.
本文介绍了一项关于拇指屈褶的胚胎发育和形态学的研究。我们使用了178例孕龄为6至20周的人类胎儿以及225名年龄在19至81岁的正常成年人，来观察屈褶的形态、出现时间和位置。研究发现，大多数屈褶，即规则、额外和斜行屈褶，是与胎儿掌垫的出现同时发育的，显然与拇指的屈曲运动无关。尽管规则屈褶通常看起来是简单的单一屈褶，但它们似乎是由从两侧向内发育的桡侧和尺侧屈褶段形成的。我们的观察还表明，拇指近节指骨上的斜行和额外屈褶应被视为常见或“规则”屈褶，而非异常，因为它们在胎儿和正常健康成年人中出现的频率很高。
