Definition of frontal bone in US English:

frontal bone


  • 1The bone which forms the front part of the skull and the upper part of the eye sockets.

    • ‘Unanimous skeletal features are few, but include a lack of contact between the squamosal and parietal bones in the skull and the presence of the frontal bone in forming the orbit.’
    • ‘An external view of a skull shows a fracture near the bregma and scalping cuts along the frontal bone.’
    • ‘Here we present a case of solitary plasmacytoma of frontal bone that was entirely asymptomatic.’
    • ‘A small vertical midline plate, termed the nasal spine of the frontal bone, contributes to the nasal septum.’
    1. 1.1 Either of the pair of bones from which the frontal bone is formed by fusion in infancy.
      • ‘In the individual with horns, the upper layer forming the horns can be separated from what appears to be the underlying normal frontal bones without obvious damage to either element.’
      • ‘Like tetrapods, but unlike all other fishes, they also have frontal bones in the skull roof.’
      • ‘They differ from other artiodactyl horns in that they do not project from the frontal bones, but lie over the sutures between the frontal and parietal bones.’
      • ‘Head lateral views showed focal increased uptake at both frontal bones and vertical enlargement of the diploe and mandibular bones.’
      • ‘The gap between the two frontal bones did not change significantly with gestation (mean: 1.5 mm; 5th centile: 1.0 mm; 95th centile: 2.0 mm).’