Methods:A retrospective case-control study was performed in patients with Crouzon syndrome treated at a large craniofacial center between 1984 and 2012. Inclusion criteria were a diagnosis of Crouzon syndrome and at least one high-quality CT scan in which SOS patency could be assessed. Age/gender matched control CT scans were identified and assessed for status of SOS patency. Three independent reviewers with high inter-rater reliability(kappa=.88) graded SOS patency on axial images as open, partially fused, or completely fused SOS. Wilcoxon Rank-Sum test was used to compare the Pfeiffer group to controls.
Results:Over the study period, 30 patients were identified as being diagnosed with Crouzon syndrome. A total of 24 patients with 112 head CT scans met inclusion criteria. All patients with Crouzon syndrome had some degree of midface hypoplasia. Accordingly, 112 age/gender-matched control CT scans were assessed, and no patient in the control group had midface hypoplasia. Within the Crouzon group, the average age of complete closure(14.33 ± 3.43 years;n=31) evident on CT scan was significantly younger than the control group(16.55 ± 2.15 years;n=18)(p=.0155). The average age of partial closure evident on CT scan was significantly younger(5.57± 2.04 years;n=43) within the Crouzon group compared to the control group(10.65 ± 2.44 years;n=18)(p=.0001). The average age of scans showing complete patency of the SOS in the Crouzon group(1.32 ± 1.07 years;n=38) was significantly younger than the control group (3.22 ± 2.30;n=76)(p=.0001).
Conclusions: The SOS closes significantly earlier in patients with Crouzon syndrome compared to age/gender-matched controls. Although causality cannot be concluded, there exists a strong correlation between midface hypoplasia and premature SOS closure in Crouzon syndrome.