title: Prenatal assessment of the antero-posterior jaw relationship in human fetuses: from anatomical to ultrasound cephalometric analysis.
abstract: OBJECTIVE
  We wished to develop an ultrasound cephalometric analysis, particularly of the antero-posterior jaw relationship, to increase the accuracy of prenatal diagnosis of retrognathism during the routine midterm test.
  
  
  METHODS
  Anatomical cephalometric analysis was performed in 18 formalin-fixed human fetuses (between 16 and 39 gestational weeks), and ultrasound cephalometry was prospectively carried out in 52 pregnant women (21 to 25 gestational weeks). The same landmarks were used in the anatomical and ultrasound median sagittal planes for comparison. Four cephalometric angles were measured relative to the anterior cranial base: alveolar projection of the maxilla and the mandible, chin projection, and facial angle. The antero-posterior jaw discrepancy was calculated.
  
  
  RESULTS
  The projection of the maxilla was similar in the two cephalometric analyses (IC [-3.39, 0.23]), whereas the values of the projection of the mandible were lower in the ultrasound sample. The slope of the regression line of the antero-posterior jaw discrepancy on fetuses' age did not show significant differences (IC [-0.05, 1.54]) between anatomical and ultrasound cephalometry, although a difference of 3.23° ± 0.78° (IC [1.69, 4.77]) was observed. Despite this variability, the projections of mandible and chin were well determined by the projection of the maxilla both in the anatomical and ultrasound sample.
  
  
  CONCLUSIONS
  Cephalometric analysis by prenatal sonography can be performed to study the antero-posterior jaw relationship. We think that this procedure could be useful to improve prenatal diagnosis of retrognathism in high-risk pregnancies. Further studies should address the reproducibility and accuracy of such analysis.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Captier
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Faure
authors.forename: Marcel
authors.initials: M
authors.lastname: Bäumler
authors.forename: François
authors.initials: F
authors.lastname: Canovas
authors.forename: Christophe
authors.initials: C
authors.lastname: Demattei
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Daures
mesh_terms: D000293:Adolescent; D000328:Adult; D000539:Alveolar Process / Q000196:embryology; D059925:Anatomic Landmarks / Q000196:embryology; D002508:Cephalometry / Q000379:methods*; D002680:Chin / Q000196:embryology; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007574:Jaw Relation Record / Q000379:methods; D008297:Male; D008334:Mandible / Q000196:embryology*; D008437:Maxilla / Q000196:embryology*; D011247:Pregnancy; D011446:Prospective Studies; D063173:Retrognathia / Q000000981:diagnostic imaging; D012737:Sex Factors; D019291:Skull Base / Q000196:embryology; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult