[Malformations of the nasal fossa and paramedian facial clefts. New perspectives].

Since choanal atresia may be associated with other cranio-facial malformations, including various degrees of nasal fossa malformation, and be a part of paramedian facial clefts, (as described by Tessier), they can be integrated into the larger group of neurocristopathies. We identified four such cases with combined clinical elements corresponding to Tessier's paramedian facial cleft, including eyelid coloboma, mild to severe choanal and nasal fossa anomalies, ethmoidal hypoplasia and anterior skull base malformation, sometimes with proboscis lateralis. These various malformations are due to abnormality of the olfactive placode and the adjacent mesenchyme. These discoveries incited us to elaborate a conception first of all on the pertinent embryology involved, second, to propose a new classification based on anatomical and pathogenic embryological considerations. And finally, since endonasal laser therapy is particularly dangerous in such cases, to propose the use of transpalatal approach to restore choanal permeability. Pediatric ENT surgeons should pay special attention to any small stigmatism of facial cleft when dealing with children affected by choanal atresia.