Palate structure in human holoprosencephaly correlates with the facial malformation and demonstrates a new palatal developmental field.

In this study we analyzed palate structure in holoprosencephaly and correlated it with the facial malformations. Eleven human holoprosencephalic fetuses (three cyclopic, two ethmocephalic, one cebocephalic, four with median cleft lip, and one with short philtrum) at 17-23 weeks of gestation and three children (age 2 1/2, 6 and 7 years) with a single central incisor were studied. Photographic and radiographic methods were used. We found that in holoprosencephaly palate structure is abnormal. The severity of this malformation decreases with decreasing severity of facial malformation. Thus, the study shows a close relationship between the facial and the palatal malformation. In all phenotypes the premaxillary area is malformed. From this region, a fan-shaped field along the midpalatal suture is involved in all facial phenotypes, the fan being broadest in cyclopia and narrowest in the short philtrum malformation. A similar fan-shaped field can be discerned in the face, where the broadest fan also indicates the greatest severity with cyclopia, and the narrowest fan the least severe median lip malformation. In the palate field, the anteroposterior furrows seemingly demarcate the field. The findings may be of importance for the future evaluation of palatal malformations in children.