Premaxillary protrusion: a sonographic clue to bilateral cleft lip and palate.

Sonograms from 49 fetuses with cleft lip, with or without cleft palate, were reviewed. Among 37 fetuses with adequate pathologic or clinical correlation, 10 (27%) demonstrated premaxillary protrusion, seen as a paranasal echogenic mass. Nine of ten fetuses with a paranasal echogenic mass proved to have bilateral cleft lip and cleft palate. Conversely, only two of 27 fetuses who did not show a paranasal echogenic mass proved to have bilateral cleft lip and cleft palate, and neither of these fetuses showed premaxillary protrusion at birth. Sonographic evaluation of the cleft alone erroneously misclassified eight fetuses with bilateral cleft lip and cleft palate as having unilateral clefts. Premaxillary protrusion is an important clue to the presence of cleft lip and cleft palate and may be more conspicuous than the cleft itself. Furthermore, the presence of a paranasal echogenic mass favors the presence of bilateral cleft lip and cleft palate, even when sonographic evaluation of the cleft itself suggests a unilateral cleft. This information should be useful in the detection and management of fetuses with suspected facial clefts.