Three-dimensional ultrasound diagnosis of cleft palate: 'reverse face', 'flipped face' or 'oblique face'--which method is best?Ultrasound Obstet Gynecol. 2009 Apr; 33(4):399-406.UO
To compare the performance of three sonographic techniques, the 'reverse-face', 'flipped-face' and 'oblique-face' methods, for visualizing the hard and soft palate in diagnosing cleft lip and palate (CLP).
A total of 60 fetuses (10 with CLP) with a gestational age ranging from 20 to 33 weeks were examined. We compared visualization of the secondary palate with the previously described reverse-face and flipped-face methods (the latter modified by us) and the oblique-face method developed by us using Oblique View imaging technology.
Among the 10 fetuses with CLP the defect involved the lip, alveolus and secondary palate in seven, and the primary palate only in the remaining three. The upper lip and alveolar ridge were well visualized in all cases with all three methods. Involvement of the hard palate was diagnosed correctly in 71% (5/7) of the cases using the reverse-face view, in 86% (6/7) with the flipped-face view, and in 100% (7/7) with the oblique-face view; the hard palate was correctly found to be intact in 78%, 84% and 86%, respectively, of the 50 normal fetuses examined with each view. Involvement of the soft palate was diagnosed correctly in only one of the seven fetuses with defects of the secondary palate in flipped-face and oblique-face views, and was correctly considered intact in only 16% of normal fetuses in flipped-face view and in 26% in oblique-face images.
Accurate visualization of the soft palate requires an excellent initially acquired volume, fluid between the fetal tongue and palate, and curving of the plane to follow the structure of the palate. The oblique-face or flipped-face views make it possible to visualize the soft palate well in selected cases.