Introduction: The primary aim of this study was to assess the interobserver and intraobserver reproducibility of the first-trimester frontomaxillary facial angle (FMFA) measurement using both 2D and 3D ultrasound. Assessment of the relationship between crown-to-rump length (CRL) and FMFA measurement was also reviewed. Materials and Methods: Two experienced operators imaged the same 30 patients over a 1-month period collecting both 2D static images and 3D volumes during nuchal translucency assessment at 11-14 weeks' gestation. The operators were blinded to each other's images and results. Results: The mean 2D FMFA measurement was 88.0° and 88.4° for observer 1 and 2, respectively; while the mean 3D FMFA measurement was 87.8° and 88.0°, respectively. Intraclass correlation suggests good intraobserver and interobserver agreement with no statistically significant difference between operators in either 2D (p = 0.14) or 3D (p = 0.11) measurements. The FMFA was unchanged with increasing CRL. Discussion: Both 2D and 3D FMFA measurements have been demonstrated to be equivalent and reliable. Strict image acquisition criteria must be followed for accurate and reproducible FMFA measurements. There was no change demonstrated in FMFA measurement with increasing CRL.

Keywords:
Frontomaxillary, Facial angle, Ultrasound, 2D imaging, 3D imaging, First trimester
1.
Cicero S, Bindra R, Rembouskos G, Tripsanas C, Nicolaides KH: Fetal nasal bone length in chromosomally normal and abnormal fetuses at 11-14 weeks of gestation. J Maternal-Fetal Neonat Med 2002;11:400-402.
2.
Cicero S, Longo D, Rembouskos G, Sacchini C, Nicolaides KH: Absent nasal bone at 11-14 weeks of gestation and chromosomal defects. Ultrasound Obstetr Gynecol 2003;22:31-35.
3.
Mavrides E, Sairam S, Hollis B, Thilaganathan B: Screening for aneuploidy in the first trimester by assessment of blood flow in the ductus venosus. BJOG 2002;109:1015-1019.
4.
Falcon O, Auer M, Gerovassili A, Spencer K, Nicolaides KH: Screening for trisomy 21 by fetal tricuspid regurgitation, nuchal translucency and maternal serum free β-hCG and PAPP-A at 11 + 0 to 13 + 6 weeks. Ultrasound Obstetr Gynecol 2006;27:151-155.
5.
Bilardo CM, Timmerman E, Robles De Medina PG, Clur SA: Low-resistance hepatic artery flow in first-trimester fetuses: an ominous sign. Ultrasound Obstetr Gynecol 2011;37:438-443.
6.
Nicolaides KH: Turning the pyramid of prenatal care. Fetal Diag Ther 2011;29:183-196.
7.
Cicero S, Curcio P, Rembouskos G, Sonek J, Nicolaides KH: Maxillary length at 11-14 weeks of gestation in fetuses with trisomy 21. Ultrasound Obstetr Gynecol 2004;24:19-22.
8.
Dagklis T, Borenstein M, Peralta CF, Faro C, Nicolaides KH, Peralta CFA: Three-dimensional evaluation of mid-facial hypoplasia in fetuses with trisomy 21 at 11 + 0 to 13 + 6 weeks of gestation. Ultrasound Obstetr Gynecol 2006;28:261-265.
9.
Plasencia W, Dagklis T, Sotiriadis A, Borenstein M, Nicolaides KH: Frontomaxillary facial angle at 11 + 0 to 13 + 6 weeks' gestation-reproducibility of measurements. Ultrasound Obstetr Gynecol 2007;29:18-21.
10.
Alphonse J, Cox J, Clarke J, Schulter P, McLennan A: Comparison of frontomaxillary facial angles using both 2D and 3D ultrasound at 11 + 0 to 13 + 6 weeks of gestation. Fetal Diag Ther 2010;28:14-21.
11.
McLennan AC, Schluter PJ: Construction of modern Australian first trimester ultrasound dating and growth charts. J Med Imaging Radiat Oncol 2008;52:471-479.
12.
Bland JM, Altman DG: Applying the right statistics: analyses of measurement studies. Ultrasound Obstet Gynecol 2003;22:85-93.
13.
Portney LG, Watkins MP: Foundations of Clinical Research: Applications to Practice. Third edition, 2009, Ch 26, pp 594-597.
14.
Yang X, Chen M, Wang HF, Leung TY, Borenstein M, Nicolaides KH, et al: Learning curve in measurement of fetal frontomaxillary facial angle at 11-13 weeks of gestation. Ultrasound Obstetr Gynecol 2010;35:530-534.
15.
Borenstein M, Persico N, Kaihura C, Sonek J, Nicholaides KH: Frontomaxillary facial angle in chromosomally normal fetuses at 11 + 0 to 13 + 6 weeks. Ultrasound Obstetr Gynecol 2007;30:737-741.
16.
Sonek J, Borenstein M, Dagklis T, Persico N, Nicolaides KH: Frontomaxillary facial angle in fetuses with trisomy 21 at 11-13(6) weeks. Am J Obstetr Gynecol 2007;196:271.e1-e4.
17.
Chen M, Yang X, Leung TY, Sahota DS, Fung TY, Chan LW, et al: Study on the applicability of frontomaxillary facial angle in the first-trimester trisomy 21 fetuses in Chinese population. Prenatal Diagn 2009;29:1141-1144.
18.
Vos FI, De Jong-Pleij EAP, Ribbert LSM, Tromp E, Bilardo CM: Three-dimensional ultrasound imaging and measurement of nasal bone length, prenasal thickness and frontomaxillary facial angle in normal second- and third-trimester fetuses. Ultrasound Obstetr Gynecol 2012;39:636-641.
19.
Kwon J, Son GH, Choi HM, Hur HW, Kim Y, Park Y: Frontomaxillary facial angle measurement may not be a useful early screening marker in Korean population. Ultrasound Obstetr Gynecol 2009;34:6.
20.
Jeon SR, Choi HM, Roh YH, Kim YH, Son GH, Nam KH, et al: Frontomaxillary facial angle measurements in euploid Korean fetuses at 11 weeks' to 13 weeks 6 days' gestation. J Ultrasound Med 2010;29:1565-1571.
© 2013 S. Karger AG, Basel
2013
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