The growth of the nasal septum in the 6-9 week period of foetal development - Warfarin embryopathy offers a new insight into prenatal facial development

Background: The aim of this study was to determine the role of the nasal septum in embryonic facial development. Methods: Nasal septal growth and facial profile development were examined in sagittally-sectioned 6-9 week human foetuses and compared to previously published data for later prenatal periods. To complement this data a cephalometric study of a child with untreated warfarin embryopathy was undertaken since a previous study in rats had shown warfarin exposure interferes with septal growth. Results: The results showed that prenatal septal growth was maximal during the 6-9 week period and resulted in the establishment of a facial profile that was maintained until birth. This critical period of growth corresponds to the period of warfarin exposure of the human foetus that results in the warfarin embryopathy. The cephalometric examination of a child with untreated warfarin embryopathy showed a combination of short anterior cranial base and a short maxilla had contributed to a significant retrusion of the maxilla suggestive of failure of the midface to develop over the 6-9 week period. Conclusion: These-findings would support the hypothesis that the nasal septum plays an active role in embryonic midfacial development.