Wormian bones in simple sagittal synostosis: incidence and correlations

Wormian bones are accessory cranial bones of interest to neurosurgeons, radiologists, and anthropologists. Its origin is attributed to alteration in deformational forces. Sagittal synostosis alters normal cranial development and is a suitable model to explore the role of mechanical forces in wormian bone development. We aim to study the incidence and clinical correlations of wormian bones in patients with isolated sagittal synostosis operated on at Hospital La Fe in the past 10 years.

We retrospectively reviewed clinical and radiological data from patients with isolated sagittal synostosis treated at Hospital La Fe over the past 10 years. Demographic and clinical data were collected. Preoperative CT scans, including 3D reconstructions and MIP images, were assessed for anterior fontanelle and metopic suture patency, sagittal suture fusion, presence of apical wormian bones, and anthropometric measurements.

A total of 104 patients (80 males, 24 females) were included. Mean age at diagnosis was 3.72 months; average cranial index was 0.64. Complete anterior fontanelle and metopic suture closure were observed in nine and 24 patients, respectively. Apical wormian bones were present in 41 patients. Fontanelle and metopic suture closure followed an age-dependent pattern. However, wormian bone presence was independent of age but significantly associated with occipital incline.

Apical wormian bones are frequently observed in sagittal synostosis. Their presence may reflect a compensatory response to altered cranial forces and correlates with occipital morphology. Apical wormian bones need not be included in the surgical resection plan.