Ultrasonographic evaluation of fetal facial anatomy (I): ultrasonographic features of normal fetal face in vitro study.

Background: Because of lacking skills in scanning the normal fetal facial structures and their corresponding ultrasonic features, misdiagnoses frequently occur. Therefore, we studied the appearance features and improved displaying skills of fetal facial anatomy in order to provide basis for prenatal diagnosis.

Methods: Twenty fetuses with normal facial anatomy from induced labor because of other malformations except facial anomalies were immersed in a water bath and then scanned ultrasonographically on coronal, sagittal and transverse planes to define the ultrasonic image features of normal anatomy. The coronal and sagittal planes obtained from the submandibular triangle were used for displaying the soft and hard palate in particular.

Results: Facial anatomic structures of the fetus can be clearly displayed through the three routine orthogonal planes. However, the soft and hard palate can be displayed on the planes obtained from the submandibular triangle only.

Conclusions: The superficial soft tissues and deep bony structures of the fetal face can be recognized and evaluated by routine ultrasonographic images, which is a reliable prenatal diagnostic technique to evaluate the fetal facial anatomy. The soft and hard palate can be well demonstrated by the submandibular triangle approach.