Alleviating abnormal stress on compressed cranial sutures: a potential mechanism for treating and preventing...

Abnormal stress in cranial sutures is strongly related to deformational plagiocephaly (DP) and is responsible for morphological changes in the skull, facial asymmetry, and abnormal facial tension. To evaluate the effect of biomechanical therapy on cranial sutures of DP we performed in silico analysis of normal skull in the supine position (Model 1), DP in the supine position (Model 2), and DP wearing moulding helmet (Model 3).

By utilizing 3D point cloud data, we generated finite element models (FEMs) and developed 14 cranial sutures. We evaluated the mechanical causes of the continuous progression of moderate to severe DP by comparing the Von Mises Stress (VMS) distributions of 14 cranial sutures between Model 1 and Model 2, and used the same method to compare Model 2 with Model 3 to determine the reasons for the alleviation of DP.

When the DP wore a moulding helmet, the VMS on the compressed side of the cranial sutures was reduced, and the skull support site shifted to the contralateral side. DP was associated with abnormal stress accumulation on the compressed side of the cranial sutures. Balancing the forces on both sides of the lambdoid suture, allowing the skull to accept a larger force area and applying stress to the cranial sutures on the uncompressed side may be the mechanism for the prevention and treatment of DP.

The asymmetry caused by DP may be associated with abnormal stress accumulation in cranial sutures, and eliminating abnormal stress accumulation in cranial sutures and applying stress to contralateral cranial sutures are key measures of treatment.