title: Frontomaxillary and mandibulomaxillary facial angles at 11 + 0 to 13 + 6 weeks in fetuses with trisomy 18.
abstract: OBJECTIVE
  To define the relative position of the maxilla and mandible in fetuses with trisomy 18 at 11 + 0 to 13 + 6 weeks of gestation.
  
  
  METHODS
  A three-dimensional (3D) volume of the fetal head was obtained before karyotyping at 11 + 0 to 13 + 6 weeks of gestation in 36 fetuses subsequently found to have trisomy 18, and 200 chromosomally normal fetuses. The frontomaxillary facial (FMF) angle and the mandibulomaxillary facial (MMF) angle were measured in a mid-sagittal view of the fetal face.
  
  
  RESULTS
  In the chromosomally normal group both the FMF and MMF angles decreased significantly with crown-rump length (CRL). In the trisomy 18 fetuses the FMF angle was significantly greater and the angle was above the 95(th) centile of the normal range in 21 (58.3%) cases. In contrast, in trisomy 18 fetuses the MMF angle was significantly smaller than that in normal fetuses and the angle was below the 5(th) centile of the normal range in 12 (33.3%) cases.
  
  
  CONCLUSIONS
  Trisomy 18 at 11 + 0 to 13 + 6 weeks of gestation is associated with both mid-facial hypoplasia and micrognathia or retrognathia that can be documented by measurement of the FMF angle and MMF angle, respectively.
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Borenstein
authors.forename: N
authors.initials: N
authors.lastname: Persico
authors.forename: I
authors.initials: I
authors.lastname: Strobl
authors.forename: J
authors.initials: J
authors.lastname: Sonek
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D002887:Chromosomes, Human, Pair 18; D005260:Female; D005865:Gestational Age; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008334:Mandible / Q000000981:diagnostic imaging / Q000196:embryology*; D008437:Maxilla / Q000000981:diagnostic imaging / Q000196:embryology*; D008844:Micrognathism / Q000000981:diagnostic imaging / Q000196:embryology*; D008875:Middle Aged; D011247:Pregnancy; D012044:Regression Analysis; D014314:Trisomy; D016216:Ultrasonography, Prenatal