title: Nomogram of maxillary bone length in normal pregnancies.
abstract: OBJECTIVE
  The aim of this study was to define normal ultrasonographic growth of the fetal maxillary bone throughout pregnancy as a basis for further studies and as normative data for assessing deviations in growth.
  
  
  METHODS
  A prospective cross-sectional study was performed. Consecutive routine biometric measurements and fetal organ scans were obtained from patients undergoing elective fetal anatomic surveys. Special attention was paid to the profile view of the fetal face, and the maxillary bone was identified and measured.
  
  
  RESULTS
  Three hundred twenty-seven fetuses between 13 and 40 weeks' gestation were scanned. The maxillary bone is seen as a rodlike structure; it is a part of the facial skeleton that allows the opening and closing of the pharynx. A linear growth function was observed across gestational age (GA), and first-degree correlation was found to exist between GA and the maxillary bone (r = .645; P < .0001; y = 7.78 + 0.18 x GA). Significant correlation was also found between the maxillary bone and biparietal diameter (BPD) (r = 0.652; P > .0001; y = 8.36 + 0.66 x BPD), head circumference (HC) (r = .645; P < .0001; y = 8.39 + 0.18 x HC), femoral bone length (FBL) (r = .640; P < .0001; y = 9.28 + 0.7 x FBL), and abdominal circumference (AC) (r = .640; P < .0001; y = 8.91 + 0.17 x AC).
  
  
  CONCLUSIONS
  Normative data for ultrasonographic measurements of the fetal maxillary bone throughout pregnancy are provided. These data potentially allow the prenatal diagnosis of abnormal maxillary bone length.
authors.affiliation: Department of Obstetrics and Gynecology, Rambam Medical Center, PO Box 9602, Haifa 31096, Israel. i_goldstein@rambam.health.gov.il
authors.forename: Israel
authors.initials: I
authors.lastname: Goldstein
authors.forename: Ari
authors.initials: A
authors.lastname: Reiss
authors.forename: Bat-Sheva
authors.initials: BS
authors.lastname: Rajamim
authors.forename: Ada
authors.initials: A
authors.lastname: Tamir
mesh_terms: D001699:Biometry; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D008437:Maxilla / Q000000981:diagnostic imaging / Q000196:embryology*; D049451:Nomograms; D011247:Pregnancy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal