The three-dimensional ultrasonography of the fetal face--history and progress.

Fetal face was the main concern of researchers who developed three-dimensional ultrasound. 3-D ultrasound beginnings date back to 1973. Parallel concerns of researchers from different parts of the world have led to a constantly changing the equipment and software. 3-D images of the fetal face were obtained since 1986, but those that are available on the ultrasound devices sold today dates from 1992, and the 4-D since 1996. Techniques such as volume rendering and multiplanar volume rendering, led to the development of 3-D ultrasound. Late 2000 revealed study fetal face by multiplane three-dimensional ultrasound, through the acquisition of volume and its processing. Study of fetal profile by this method provides new data on the jaw, naso-maxillo-mandibular angle, even a diagram of the fetal profile or of dimensions of the fetal face or nasal bone length. Fetal profile analyzed by 16 parameters measured by 3-D ultrasound, with the creation of a craniofacial index variable is useful in assessing normal and abnormal fetal face. Today, the bones of fetal face--nose, jaw, bone palace, those of the orbit, can be studied in dynamics, from 12-14 gestational weeks. The best ultrasound images can be obtained after 21 gestational weeks, when fetal size and its ratio with amniotic fluid are optimal for the acquisition of fetal volume.