First Trimester Ultrasound Evaluation of the Cleft Palate: Midsagittal, Axial or Coronal View-Which View is Best?

Abstract

Objective First trimester evaluation of the palate is now gaining importance and the ''maxillary gap sign'' described in the midsagittal view and the retronasal triangle serves as a potential marker for detection of cleft palate (CP). The objective is to describe an ultrasound technique for evaluation of the palate in the axial view and to assess the utility of this view in assessing palatine clefts. Materials and methodsThe anatomical landmarks in sagittal, coronal and in axial view were evaluated in 17 cases of palatine clefts with known postnatal outcomes. Along with the midsagittal and coronal view, the alveolar ridge of the maxilla and the echogenic secondary palate was examined in the transverse view of the base of the skull at the level of the pharynx. Results Visualisation of the bony landmarks of the palate in all three planes was possible in all cases. Of the 17 cases, there were 7 unilateral Cleft Lips Palate (CLP), 5 bilateral CLP, 2 median CLP, 2 isolated CP and 1 atypical cleft. 2 cases of bilateral CLP showed no demonstrable maxillary gap in the midsagittal view (the vomer can often mimic the maxillary line). 2 cases showed a normal retronasal triangle (RNT) when the cleft was confined to the premaxilla alone. However, the axial view showed abnormal appearance in all 17 cases. Conclusion A combination of all three planes can be used as an effective screening tool but the axial view has more potential for detection of CP in first trimester. However large scale prospective studies are needed to confirm this observation.