Craniosynostosis: Quantifying Differences in Skull Architecture.

Craniosynostosis, a condition marked by the premature fusion of one or more cranial sutures, exhibits diverse phenotypes. This study aims to advance the understanding of these phenotypes beyond the conventional 2-dimensional analysis by focusing on identifying indicators of increased intracranial pressure (ICP) such as bony thinning or irregularities in skull morphology. A retrospective review was conducted for all pediatric patients with midline craniosynostosis who presented to our tertiary academic center for evaluation. Control patients were carefully selected to match for age, sex, and weight. All computed tomography data were segmented in 3-dimensional Slicer and then delineated along with suture lines into occipital, parietal, and frontal segments. Main outcome measures included general skull shape (assessed via measures of flatness and surface area to volume ratio) and skull topography (analyzed via measures of bone thickness, surface variance, and surface standard deviation). Forty-one patients with midline craniosynostoses were identified (22 metopic and 19 sagittal). Patients with sagittal craniosynostosis had significantly angulated frontal and occipital bones, reflective of the frontal bossing and occipital bulleting commonly seen in this population, and significantly flatter parietal bones, reflective of limited growth along with the transverse axis. Interestingly, evaluation of bone topography revealed that patients with sagittal craniosynostosis had significantly higher parietal bone surface variance, reflective of gyral impressions secondary to increased ICP. In contrast, patients with metopic craniosynostosis had statistically flatter frontal bones-reflective of limited anterior brain growth caused by the fused metopic suture-with minimal impacts to parietal or occipital bones.