The frontal bone is a wide or flat bone, situated forward and upward and has two portions: a vertical one, the scale, and a horizontal one, the roofs of the orbital and nasal cavities.
Outer Face : this face is convex and on it we find the following structures:
- Supra-Orbital Edge
- Frontal tuber – 3 cm above the supraorbital border
- Superciliary Arches – ridges that extend laterally to the glabella
- Glabella – between the two superciliary arches (anthropometric point)
- Metopic suture – found in some rare cases and located just above the glabella and extending to the bregma through the midsagittal line. This suture, in childhood, divides the bone in two and can remain for life.
- Notch or Supraorbital foramen - passage of supraorbital vessels and nerves.
- Nasal Notch – rough and irregular gap
- Nasal Spine – located anteriorly and in the center of the nasal notch
Inner face :
- Front Crest
- foramen cecum – located at the end of the frontal crest and is where the dura mater inserts
Ceilings of Orbital and Nasal Cavities
They form the roof of the orbit, the ethmoidal notch (separates the two orbital laminae) and the ostia of the frontal sinus (anterior to the ethmoidal notch). This sinus makes the frontal bone with characteristics of a pneumatic, hollow bone.
The Frontal articulates with twelve bones: Sphenoid, Ethmoid, Parietal (2), Nasal (2), Maxillary (2), Lacrimal (2) and Zygomatic (2).
| FRONT - FRONT VIEW|
|Source: SOBOTTA, Johannes. Atlas of Human Anatomy. 21 ed. Rio de Janeiro: Guanabara Koogan, 2000|
| FRONT - BOTTOM VIEW|
|Source: SOBOTTA, Johannes. Atlas of Human Anatomy. 21 ed. Rio de Janeiro: Guanabara Koogan, 2000.|