Background: Cranial base sutures are important drivers of both facial and cranial growth. The purpose of this study was to compare the incidence and location of cranial base suture fusion among three groups: nonaffected controls, patients with nonsyndromic craniosynostosis, and patients with syndromic craniosynostosis.
Methods: Patients and computed tomographic scans were accrued from the authors' prospective craniofacial database. Computed tomographic scans were graded on the frequency of cranial vault and cranial base suture/synchondrosis fusion (0, open; 1, partially/completely fused) by an attending craniofacial surgeon and neuroradiologist. Statistical comparisons were conducted on location and rates of fusion, age, and diagnosis.
Results: One hundred forty patients met inclusion criteria: 55 syndromic, 64 nonsyndromic, and 21 controls. Average age at computed tomography of syndromic patients (3.6 ± 3.1 months) was younger than that of nonsyndromic patients (5.4 ± 3.1 months; p = 0.001) and control subjects (5.1 ± 3.2 months; p = 0.058). Syndromic craniosynostotic patients had over three times as many cranial base minor sutures fused (2.2 ± 2.5) as nonsyndromic craniosynostosis patients (0.7 ± 1.2; p < 0.001) and controls (0.4 ± 0.8; p = 0.002), whose rates of fusion were statistically equivalent (p = 0.342). Syndromic craniosynostosis patients had a greater frequency of cranial base suture fusion in the coronal branches, squamosal arch, and posterior intraoccipital synchondrosis (p < 0.05).
Conclusions: Patients with syndromic craniosynostosis have higher rates of cranial base suture fusion in infancy, especially in the coronal arches, and this may have significant implications for both cranial and facial growth. In contrast, patients with nonsyndromic craniosynostosis have similar rates and sites of cranial base suture fusion as controls. Interestingly, there is a low, "normal," rate of cranial base suture/synchondrosis closure in infancy, the implications of which are unknown.
Clinical question/level of evidence: Risk, III.