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Obstetrics and Gynecology International
Volume 2013 (2013), Article ID 847293, 5 pages
Clinical Study

The Effect of Ethnicity on 2D and 3D Frontomaxillary Facial Angle Measurement in the First Trimester

1The University of Sydney, Faculty of Health Sciences, P.O. Box 170, Lidcombe, NSW 1825, Australia
2Sydney Ultrasound for Women, Suite 114, Level 1, Q Central, 10 Norbrik Drive, Bella Vista, NSW 2153, Australia
3The University of Canterbury, School of Health Sciences, Private Bag 4800, Christchurch 8140, New Zealand
4The University of Queensland, School of Nursing and Midwifery, Level 2, Edith Cavell Building, UQ, Herston Campus, Qld 4029, Australia
5The University of Sydney, Faculty of Medicine, Camperdown, NSW 2066, Australia

Received 29 April 2013; Accepted 30 August 2013

Academic Editor: Kimberly K. Leslie

Copyright © 2013 Jennifer Alphonse et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objectives. To determine the existence and extent of ethnic differences in 2D or 3D fetal frontomaxillary facial angle (FMFA) measurements. Methods. During routine 11–14 weeks nuchal translucency screening undertaken in a private ultrasound practice in Sydney, Australia, 2D images and 3D volumes of the fetal profile were collected from consenting patients. FMFA was measured on a frozen 2D ultrasound image in the appropriate plane and, after a delay of at least 48 hours, was also measured on the reconstructed 3D ultrasound volume offline. Results. Overall 416 patients were included in the study; 220 Caucasian, 108 north Asian, 36 east Asian and 52 south Asian patients. Caucasians had significantly lower median FMFA measurements than Asians in both 2D (2.2°; ) and 3D (3.4°; ) images. Median 2D measurements were significantly higher than 3D measurements in the Caucasian and south Asian groups ( and ), but not in north and east Asian groups ( and ). Conclusions. Significant ethnic variations in both 2D and 3D FMFA measurements exist. These differences may indicate the need to establish ethnic-specific reference ranges for both 2D and 3D imaging.