[Sonographic evaluation of fetal clefts of the lip, alveolus and palate].

Clefts of the lip, alveolus and palate are among the most common congenital malformations. Due to their frequent combination with other structural anomalies, chromosomal defects and genetic syndromes, the prenatal diagnosis of clefts plays an important role. Furthermore, the prenatal detection of clefts enhances the parents' psychological preparation and enables the planning of postnatal management. This article reviews the occurrence, appearance and pathophysiology of these malformations as well as the different sonographic techniques used to diagnose clefts and their extent. Previously reported 2D- and 3D-techniques as well as our own recent diagnostic approach focussing on the diagnosis of isolated cleft palate are described.