From the Department of Plastic Reconstructive Surgery, Osaka Medical College; Food and Nutrition, Japan Women's University; and Molecular Craniofacial Embryology, Tokyo Medical and Dental University.
Plast Reconstr Surg. 2022 Jan 1;149(1):28e-37e. doi: 10.1097/PRS.0000000000008665.
The haploinsufficiency in the TWIST1 gene encoding a basic helix-loop-helix transcription factor is a cause of one of the craniosynostosis syndromes, Saethre-Chotzen syndrome. Patients with craniosynostosis usually require operative release of affected sutures, which makes it difficult to observe the long-term consequence of suture fusion on craniofacial growth.
In this study, we performed quantitative analysis of morphologic changes of the skull in Twist1 heterozygously-deleted mice (Twist1+/-) with micro-computed tomographic images.
In Twist1+/- mice, fusion of the coronal suture began before postnatal day 14 and progressed until postnatal day 56, during which morphologic changes occurred. The growth of the skull was not achieved by a constant increase in the measured distances in wild type mice; some distances in the top-basal axis were decreased during the observation period. In the Twist1+/- mouse, growth in the top-basal axis was accelerated and that of the frontal cranium was reduced. In the unicoronal suture fusion mouse, the length of the zygomatic arch of affected side was shorter in the Twist1+/- mouse. In one postnatal day 56 Twist1+/- mouse with bilateral coronal suture fusion, asymmetric zygomatic arch length was identified.
The authors'results suggest that measuring the length of the left and right zygomatic arches may be useful for early diagnosis of coronal suture fusion and for estimation of the timing of synostosis, and that more detailed study on the growth pattern of the normal and the synostosed skull could provide prediction of the risk of resynostosis.
The data from this study can be useful to better understand the cranial growth pattern in patients with craniosynostosis.
TWIST1 基因编码一个基本的螺旋-环-螺旋转录因子，其杂合缺失是颅缝早闭综合征之一——Saethre-Chotzen 综合征的病因。颅缝早闭患者通常需要手术松解受累的缝线，这使得很难观察到缝线融合对颅面生长的长期影响。
在这项研究中，我们使用微计算机断层扫描图像对 Twist1 杂合缺失小鼠（Twist1+/-）的颅骨形态变化进行定量分析。
在 Twist1+/- 小鼠中，冠状缝融合在出生后第 14 天前开始，并持续到第 56 天，在此期间发生了形态变化。野生型小鼠的测量距离不断增加，从而实现了颅骨的生长；在观察期间，一些顶底轴的距离减小了。在 Twist1+/- 小鼠中，顶底轴的生长加速，而额颅骨的生长减少。在单侧冠状缝融合的小鼠中，受影响侧的颧骨弓长度在 Twist1+/- 小鼠中更短。在一只双侧冠状缝融合的出生后第 56 天的 Twist1+/- 小鼠中，发现了不对称的颧骨弓长度。
作者的结果表明，测量左右颧骨弓的长度可能有助于早期诊断冠状缝融合，并估计融合的时间，对正常和融合颅骨的生长模式进行更详细的研究可以预测再融合的风险。
这项研究的数据可以帮助更好地理解颅缝早闭患者的颅骨生长模式。
