The Accuracy of Classification Systems in Nonsyndromic Sagittal Craniosynostosis

Abstract

Numerous classification systems of nonsyndromic sagittal craniosynostosis (NSC) are applied but none has gained a wide acceptance, since each classification is focused on distinct aspects. The aim of the study was to assess the accuracy of 4 classifications of NSC discussed in the literature by defining the associations among the classifications, individual features (sex, age, cranial index), and objective morphologic criteria (frontal bossing, retrocoronal constriction, sagittal ridge, and occipital bulleting). The study was conducted on anonymized thin-cut CT scans of 133 children with NSC 1 to 12 months old (mean age 5.42 mo). The type of cranial dysmorphology was assessed using 4 classification systems, focusing on skull shape, pattern of sagittal suture closure (Heuzé classification), deformation of skull vault (Sakamoto classification), and a single-dominant feature (David classification). Each patient was also independently investigated for the presence of morphologic criteria. A multivariate analysis was performed to explore the relations among the classifications and assess their accuracy. In the analyzed cohort sphenocephaly (38.3%), CFF type by Heuzé (30.8%), type I by Sakamoto (72.9%), and a central type by David (42.9%) were dominant findings. Regarding the morphologic criteria, frontal bossing was observed the most frequently (91.7%). The age of patients and cranial index differed significantly among the shapes of skull and David classifications (P<0.001). The shape-based system showed the strongest correlation with other classifications and with measurable variables. Other classifications have much in common and some overlap, but none of them constitutes a standalone system to define all aspects of cranial dysmorphology in NSC.