An objective measurement to diagnose micrognathia on prenatal ultrasound.
OBJECTIVE
We introduce the frontal naso-mental angle as an objective measurement for the prenatal detection of fetal retrognathia. The aim of this study is to present normal values for the frontal naso-mental angle from 18 to 35 weeks gestational age.


METHODS
In 81 patients between gestational ages 18 and 35 weeks the frontal naso-mental angle was measured on a profile view of the foetal face. The values were compared with four cases of proven Pierre Robin syndrome.


RESULTS
The frontal naso-mental angle is not dependent on gestational age, the mean value is 146.74 degrees, standard deviation 2.7 degrees; 5th percentile 142 degrees, 95th percentile 151 degrees. All four cases of Pierre Robin syndrome demonstrated a significantly lower frontal naso-mental angle below the 5th percentile.


CONCLUSIONS
The frontal naso-mental angle represents an objective way to diagnose retrognathia.
Palit
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Department of Obstetrics and Gynaecology Antwerp University Hospital UZA, Edegem, Belgium.
Jacquemyn
Y
Y
Kerremans
M
M
D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D008844:Micrognathism / Q000000981:diagnostic imaging*; D010855:Pierre Robin Syndrome / Q000000981:diagnostic imaging*; D011247:Pregnancy; D012016:Reference Values; D016216:Ultrasonography, Prenatal