SONOGRAPHIC DEPICTION OF FETAL TOOTH GERMS

Recently, sonography of the fetal face has gained increasing importanc e in prenatal diagnosis. It is not yet clear whether sonographic depic tion of fetal tooth germs would have an influence on the prenatal diag nosis of ectodermal dysplasia syndromes. During routine malformation s creening, horizontal sections of fetal jaws were visualized and examin ed for tooth germs in 124 pregnant women following sonographic 'facing '. Histological jaw sections of fetuses that had died in utero at vari ous gestational ages were produced in order to examine the degree of c orrespondence between the sonographic and histological findings. At le ast four tooth germs were found in the jaws of all fetuses between 19 and 34 gestational weeks (n=104). Although jaw visualization was possi ble between 14 and 18 gestational weeks (n=20), the exact number and l ocation of the tooth germs could not be determined. Assessment of toot h germs may become increasingly important, as aplasia of the tooth ger ms is one of the principal signs of various hereditary ectodermal dise ases.