Squamosal Craniosynostosis: Defining the Phenotype and Indications for Surgical Management

Squamosal craniosynostosis is seldom reported in the craniofacial literature. Given that this is an uncommon diagnosis, phenotype and management remain unclear. The authors present a case series and review the literature to define the phenotype and management of these patients.

We retrospectively reviewed 7 patients from our institution and systematically reviewed all published cases of squamosal craniosynostosis. Demographics, medical history, imaging, clinical presentation, subsequent workup, and treatment were examined and analyzed.

A comprehensive review of the literature yielded a total of 31 cases (including our new series) of squamosal craniosynostosis. Average age of presentation was 25.3 months, 52% of female patients, 74% of cases with bilateral squamosal involvement, 44% syndromic, 39% isolated squamosal (vs 61% multisutural). Overall, 56% of cases were handled surgically, whereas 44% were managed conservatively. Thirty-three percent of surgical cases required multiple operations. One patient with isolated bilateral squamosal craniosynostosis developed elevated intracranial pressure, requiring cranial vault remodeling.

Squamosal craniosynostosis frequently presents in a delayed fashion with nonsyndromic, bilateral involvement. In isolated bilateral squamosal cases, the associated phenotype is frontal prominence, occipital flattening, scaphocephalic tendency (low-end normocephalic cranial index), and superior parietal cornering. Evaluation of clinical signs and computed tomography imaging guides management, as evidence of increased intracranial pressure may indicate need for cranial vault expansion. Although previous literature suggests that nonsyndromic cases are nonsurgical, the majority of cases reviewed required surgical intervention, including our case of isolated bilateral squamosal craniosynostosis. We recommend vigilant management in patients with squamosal craniosynostosis, even those with isolated squamosal involvement.