Frontal bone: anatomy of the forehead and brow
- Highlighted area
Quick facts
- Location
- Forms the forehead, the roof of the orbits and the upper part of the orbital rim.
- Parts
- Squama (the forehead), orbital parts (roof of the orbit) and nasal part, which articulates with the nasal bones.
- Landmarks
- Frontal eminences, brow ridges, glabella, supraorbital notch or foramen, frontal notch and temporal line.
- Frontal sinus
- Air cavity inside the bone, behind the brow ridges, of variable size.
- Relevance in facial harmonization
- Base of the forehead and brow; the foramina mark the exit of supraorbital and supratrochlear vessels and nerves.
The frontal bone is the bone that forms the forehead, the roof of the orbits and the upper part of the orbital rim. It is divided into the squama, the vertical part of the forehead, the orbital parts, which form the roof of each orbit, and the nasal part, which articulates with the bones of the nose. In facial harmonization, it is the base on which the muscles of the forehead and glabella work, and its foramina mark the exit of vessels and nerves important for safety in the upper third.
What are the landmarks of the frontal bone?
| Landmark | Where it is | Why it matters |
|---|---|---|
| Frontal eminences | Two rounded elevations on the forehead | Define the curvature of the forehead, more pronounced in many women |
| Brow ridge | Elevation above each orbit | More prominent in many men; base of the brow |
| Glabella | Smooth area between the brow ridges | Region of the glabella and of the corrugator and procerus muscles |
| Supraorbital notch or foramen | Upper orbital rim, usually in the medial third | Exit of the supraorbital artery and nerve |
| Frontal notch (or foramen) | Medial to the supraorbital | Exit of the supratrochlear vessels and nerve |
| Temporal line | Curved ridge on the side of the forehead | Boundary between the forehead and temple; attachment of the temporal fascia |
| Zygomatic process | Lateral corner of the orbit | Articulates with the zygomatic bone |
| Frontal sinus | Inside the bone, behind the ridges | Variable size; does not show on the surface |
Why does it matter in facial harmonization?
- Toxin in the forehead and glabella: the frontalis muscle rests on the squama, and the corrugator originates next to the brow ridge. The shape of the forehead and the height of the brow relative to the orbital rim guide how the toxin is distributed. The topic is covered in forehead lines and in botulinum toxin for the brow.
- Forehead shape and gender: a more vertical, rounded forehead with a subtle brow ridge tends to be read as feminine; a more pronounced ridge and a sloping forehead, as masculine. This enters into facial feminization and masculinization planning.
- Aging of the upper orbit: remodeling of the orbital rim and loss of soft tissue volume cause the brow to lose support, which adds to the tired look.
How does it show up in the assessment?
- Profile: shows the curvature of the forehead, the projection of the brow ridge and the transition to the nose at the nasion.
- Palpation of the orbital rim: the supraorbital notch is usually palpable as a small depression.
- Brow at rest and raised: reveals how much the frontalis works to hold up the brow.
- Side lighting: highlights depressions and irregularities of the forehead.
Also called: frontal, forehead bone, os frontale.
Frequently asked questions
Does the frontal bone change with age?
The upper orbital rim goes through remodeling with aging, especially in the medial part, which contributes to the look of a more hollow orbit. The forehead changes more from soft tissue volume loss and muscle action than from the bone.
Terms mentioned
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