title: Measurement of fetal maxillary and mandibular angles for first-trimester prenatal screening among Taiwanese women.
abstract: BACKGROUND
  Early fetal structure evaluation is crucial. Fetal abnormalities might indicate chromosomal anomalies or abnormal fetal growth. The aim of this study was to establish the appropriate reference range of maxillary and mandibular angles among the Taiwanese population at 11(+0)-13(+6) weeks of gestation in normal singleton pregnancy as reference values for prenatal ultrasonographic examinations.
  
  
  METHODS
  Fetal ultrasonographic data on maxillary angles and mandibular angles at a gestational age ranging from 11(+0) weeks to 13(+6) weeks were recorded in this study. Maternal background and pregnancy outcome were obtained from hospital records.
  
  
  RESULTS
  A total of 87 patients were included in this study. Maxillary and mandibular angles were successfully recorded in 87 (100%) and 84 (96.6%) patients, respectively. The mean maternal age was 31 (range, 19-41) years, with a corresponding gestational age of 12(+4) (range, 11(+0)-13(+6)) weeks. The maxillary and mandibular angles were 79.9° ± 15.6° and 71.0° ± 12.8°, respectively. First-degree correlation was not found to exist between gestational age and maxillary and mandibular angles.
  
  
  CONCLUSIONS
  Normative data for ultrasonographic measurements of maxillary and mandibular angles among the Taiwanese population are presented. Our results may serve as reference values in congenital anomaly screening during prenatal examination.
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Fan-Hlan
authors.initials: FH
authors.lastname: Koo
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Peng-Hui
authors.initials: PH
authors.lastname: Wang
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan, ROC; Taipei Mackay Memorial Hospital, Taipei, Taiwan, ROC; Mackay Medicine, Nursing, and Management College, Taipei, Taiwan, ROC.
authors.forename: Hsing-I
authors.initials: HI
authors.lastname: Wang
authors.affiliation: Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Wu
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Chi-Mou
authors.initials: CM
authors.lastname: Juang
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Chen
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Chia-Ming
authors.initials: CM
authors.lastname: Chang
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Huann-Cheng
authors.initials: HC
authors.lastname: Horng
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan, ROC. Electronic address: zachary.joyce@gmail.com.
authors.forename: Chih-Yao
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Tsai
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Ming-Jie
authors.initials: MJ
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Ming-Shyen
authors.initials: MS
authors.lastname: Yen
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Department of Obstetrics and Gynecology, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Kuan-Chong
authors.initials: KC
authors.lastname: Chao
mesh_terms: D000328:Adult; D044466:Asian People; D005260:Female; D006801:Humans; D008334:Mandible / Q000196:embryology*; D008437:Maxilla / Q000196:embryology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis; D012016:Reference Values; D013624:Taiwan; D016216:Ultrasonography, Prenatal
keywords: fetal ultrasound; mandibular angle; maxillary angle; prenatal screening