Seasonal Influence on the Numbers of Gender-Related Orofacial Cleft Conceptions in the Netherlands.

Background: In the multifactorial etiology of orofacial clefts (OFCs), environmental factors play an important role. To trace the influence of these factors, the timing of the cell biological mechanisms that occur during embryological development of the primary and secondary palates must be taken into account. That is, the fusion process of the facial and palatal processes, respectively, followed by their differentiation into bone and musculature, which take place during the first trimester of pregnancy.

Embryologically Based Classification Specifies Gender Differences in the Prevalence of Orofacial Cleft Subphenotypes.

Background: A recently published validated classification system divides all orofacial cleft (OFC) subphenotypes into groups based on underlying developmental mechanisms, that is, fusion and differentiation, and their timing, that is, early and late periods, in embryogenesis of the primary and secondary palates.

Aims: The aim of our study was to define gender differences in prevalence for all subphenotypes in newborns with OFC in the Netherlands.

Methods: This was a retrospective cross-sectional study on children with OFC born from 2006 to 2016.