The frontal bone is a single bone that forms the anterior of the cranial vault, the roof of the eye sockets, and a small portion of the nasal cavity. A temporal line can be found on both lateral surfaces of the frontal bone. The line begins in the region of the eye socket and proceeds posteriorly, often dividing into superior and inferior temporal lines near the posterior border of the frontal bone (Figure)
Frontal Bone consists of three portions:
- a vertical portion, the squama frontalis, corresponding with the region of the forehead.
- an orbital or horizontal portion, the pars orbitalis, which enters into the formation of the roofs of the orbital and nasal cavities.
- a nasal portion, it articulates with the nasal bones and the frontal process of the maxilla to form the root of the nose.
The frontal bone is presumed to be derived from neural crest cells.
The border of the squama frontalis is thick, strongly serrated, bevelled at the expense of the inner table above, where it rests upon the parietal bones, and at the expense of the outer table on either side, where it receives the lateral pressure of those bones; this border is continued below into a triangular, rough surface, which articulates with the great wing of the sphenoid. The posterior borders of the orbital plates are thin and serrated, and articulate with the small wings of the sphenoid.