Premature Fusion of the Sagittal Suture as an Incidental Radiographic Finding in Young Children

Craniosynostosis typically develops prenatally and creates characteristic changes in craniofacial form. Nevertheless, postnatal forms of craniosynostosis have been described. The purpose of this study was to determine the prevalence of incidentally identified, but temporally premature, cranial suture fusion in normocephalic children.

Computed tomographic scans obtained from children aged 1 to 5 years evaluated in the authors' emergency department between 2005 and 2016 were reviewed for evidence of craniosynostosis. Patients with prior ventriculoperitoneal shunt, brain or cranial abnormality, or known syndromes were excluded. The presence of craniosynostosis and cranial index was assessed by a panel of three craniofacial surgeons and one pediatric neurosurgeon. Demographic information, fusion type, reason for the computed tomographic scan, and medical history were recorded as covariates. Cranial shape and intracranial volume were calculated using a previously validated automated system.

Three hundred thirty-one patients met the inclusion criteria. The mean age was 2.4 ± 1.3 years. Eleven patients (3.3 percent) were found to have a complete (n = 9) or partial (n = 2) fusion of the sagittal suture. All patients had a normal cranial index (0.80; range, 0.72 to 0.87) and a grossly normal head shape. Only two fusions (18.2 percent) were documented by the radiologist. Cranial shape analysis performed in five of the 11 patients showed subtle phenotypic changes along the scaphocephaly spectrum in four patients, with a normal shape in the remaining case.

Sagittal fusion is present in 3.3 percent of otherwise phenotypically normal children aged 1 to 5 years. The clinical significance of this result is unclear, but routine screening of affected patients is paramount.

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