Facial skeleton displacement in non-syndromic brachycephaly.

To analyse the deformations affecting the facial skeleton as a consequence of craniosynostosis in isolated brachycephaly, we performed a 3D vestibular orientation of a series of 41 CT scans acquired from 25 cases of brachycephaly using the 3DSlicer application. They were first superimposed using a single age-matched CT scan of patients free of craniofacial anomalies, oriented in the same way, and then superimposed onto oriented 3D templates to reduce bias. The Virchow laws were confirmed; more interestingly, in all cases, the facial skeleton was displaced upward. We hypothesised that the skeletal complex associating the petrous bone with the basi-occipital acts as an anchoring; thus, the narrowing of the skull's circumference in the sagittal plane would lift the facial skeleton.