Coronal cleft of vertebrae, a variant of normal enchondral ossification.

In 157 spontaneously aborted human embryos and fetuses the incidence and evolution of coronal cleft formation was investigated radiologically and histologically. Complete clefts were formed in nine cases and incomplete clefts in 16 cases. There was a predominance of males. It is concluded that coronal clefts are variations of normal enchondral ossification and that the notochord plays no role in its pathogenesis. Coronal clefts seen on radiographs of newborn should not be interpreted as a malformation. Thus no preventive or treatment regimen is indicated.