Molina F, Persico N, Borenstein M, Sonek J, Nicolaides K H
Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
Ultrasound Obstet Gynecol. 2008 Apr;31(4):384-7. doi: 10.1002/uog.5288.
To establish a normal range for the frontomaxillary facial (FMF) angle by three-dimensional (3D) ultrasound imaging and to examine the FMF angle in trisomy 21 fetuses at 16-24 weeks of gestation.
We measured the FMF angle using 3D volumes of the fetal profile obtained with the transducer parallel to the long axis of the nose and at 45 degrees to the palate, which had been acquired from 150 normal fetuses and 23 fetuses with trisomy 21.
In the normal group there was no significant association between the FMF angle and gestational age; the mean FMF angle was 83.9 degrees (range, 76.9-90.2 degrees ) and the 95(th) centile was 88.5 degrees . In 15 (65.2%) of the fetuses with trisomy 21 the FMF angle was greater than 88.5 degrees . Repeatability studies demonstrated that in 95% of cases the difference between two measurements of FMF angle by the same operator and different operators was less than 5 degrees .
In the majority of second-trimester fetuses with trisomy 21 the FMF angle is increased.
通过三维（3D）超声成像建立额上颌面部（FMF）角的正常范围，并在妊娠16 - 24周时检查21三体胎儿的FMF角。
我们使用与鼻长轴平行且与腭成45度角的换能器获取的胎儿面部三维容积来测量FMF角，这些容积来自150例正常胎儿和23例21三体胎儿。
在正常组中，FMF角与孕周之间无显著相关性；平均FMF角为83.9度（范围为76.9 - 90.2度），第95百分位数为88.5度。在15例（65.2%）21三体胎儿中，FMF角大于88.5度。重复性研究表明，在95%的情况下，同一操作者和不同操作者对FMF角进行两次测量的差异小于5度。
在大多数孕中期21三体胎儿中，FMF角增大。
