The incidence of craniosynostosis in the Netherlands, 1997-2007
Objects: The first aim of this study was to determine the incidence of craniosynostosis, metopic synostosis and sagittal synostosis in the Netherlands from 1997 to 2007. The second aim was to study whether a shift in the proportion of different subtypes of craniosynostosis had taken place in the Netherlands during the study period. Methods: Patients of all six units performing craniofacial procedures in the Netherlands that met the inclusion criteria participated in the study (n = 927). A logistic regression in a weight sample was used to assess the differences in both the proportion and the incidence of different subtypes of craniosynostosis each year. The angle of the metopic ridge was compared using a regression analysis. Results: The incidence of craniosynostosis increased from 2.6 per 10 000 live births in 1997 to 6.4 in 2007. The incidence of metopic synostosis showed a significant increase of 6% each year (p = 0.029). We observed a significant change in the proportion of metopic synostosis, with a mean percentage of 20% during 1997-2000 and 27% during 2001-2007 (p = 0.046). The incidence of sagittal synostosis annually increased by 3% (p = 0.89). We did not find a significant change regarding the proportion of sagittal synostosis during 2000-2001. No significant difference in the severity of metopic synostosis was found between 1997-2000 and 2001-2004. Conclusion: The incidence of craniosynostosis, metopic synostosis and sagittal synostosis is 6.4; 1.9; and 2.8 per 10,000 live births, respectively. Both the incidence and the proportion of metopic synostosis have significantly increased over the study period, concluding that metopic synostosis is on the rise.