U-shaped palatal defect in the Robin anomalad: developmental and clinical relevance.

The palatal defect in patients with the Robin anomalad was found to be U shaped. This finding is compatible with the hypothesis that the underlying dysmorphic event is usually early mandibular hypoplasia with secondary extrinsic obstruction of palatal closure by a posteriorly displaced tongue. The more common V-shaped defects of palate closure arise by a different mechanism. Unfortunately, available recurrence risk data for cleft palate do not allow for this distinction. Furthermore, physicians should be alert for instances in which the Robin anomalad is but one feature of a broader pattern of malformation. In the current study, 25% of the 28 patients ascertained as having the Robin anomalad had a recognizable syndrome for which specific, but varying, genetic counsel was indicated.