Frontal bossing

Frontal bossing


Unusual prominence of the forehead, best appreciated in fetal profile. It may be associated with chromosomal abnormality, achondroplasia or lambdoid synostosis.


A sagittal view of the fetal face is most useful for detection of frontal bossing or prominence. This is a very subjective feature, but recently 3 dimensional ultrasound has been used to generate normative data for the whole gestation period.

Differential Diagnosis

A small nose may suggest relative prominence of the forehead. Flattening of the malar area of the midface may suggest relative prominence of the forehead.

Sonographic Features

Relative prominence of the forehead in comparison to the midface and nose.

Associated Syndromes

  • Achondroplasia
  • Antley-Bixler
  • Apert
  • Chromosomal Anomalies
  • Conradi-Hunermann
  • Crouzon
  • FG
  • Generalized gangliosidosis
  • Gorlin
  • Greig
  • Hurler
  • I-cell
  • Oto-palato-digital I
  • Pfeiffer
  • Sotos
  • Teratogen Exposure
  • Thanatophoric dysplasia


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