Frontal sinus hypoplasia in unoperated older patients with craniosynostosis: a pilot study

Purpose: The purpose of this study is to determine whether patients with unoperated craniosynostosis have different frontal sinus pneumatization than unaffected controls.

Methods: Retrospective review was performed between 2009 and 2020 of previously unoperated patients with craniosynostosis older than 5 years old at first presentation to our institution. Total frontal sinus volume (FSV) was calculated using 3D volume rendering tool in Sectra IDS7 PACS system. Age-matched normative FSV data was collected from 100 normal CT scans for the control group. The two groups were statistically compared using Fisher's exact test and T-test.

Results: Study group included nine patients, 5-39 years old, median age 7 years. Frontal sinus pneumatization was absent in 12% of the normal 7-year-old controls, while frontal sinus pneumatization was absent in 89% of the studied craniosynostosis patients (p < .001). Mean FSV of the study group (113 ± 340 mm³) was significantly different from that of age matched control mean FSV (2016 ± 2529 mm³) (p = .027).

Conclusions: Frontal sinus pneumatization is suppressed in unreleased craniosynostosis and may be an intracranial space conservation phenomenon. This absent frontal sinus can have implications in future frontal region trauma and frontal osteotomies.