The frontalis is the only muscle that elevates the brow. Unlike most facial muscles, it inserts into skin rather than bone and has no bony origin, arising from the galea aponeurotica above.
| Origin | Skin and subcutaneous tissue of the eyebrow and above |
|---|---|
| Insertion | Galea aponeurotica — blending with the occipitalis posteriorly |
| Nerve Supply | Facial nerve — temporal branch (VII) |
| Blood Supply | Supratrochlear and supraorbital arteries |
| Actions | Elevates the eyebrows; Wrinkles the forehead horizontally; Assists in eye opening — compensatory in ptosis |
|---|
Frontalis is the primary target for forehead botulinum injection — overtreatment produces brow ptosis. In brow ptosis, the frontalis compensatorily overacts to maintain visual field, producing excessive forehead wrinkling that should not be over-botulated. Endoscopic brow lift surgery elevates the brow by releasing periosteal attachments below the frontalis.
Visible as the forehead wrinkle-producing muscle during raised eyebrows.
Excessive frontalis activity to lift a ptotic brow maintaining visual field, producing forehead rhytids that require brow lift rather than frontalis botulinum treatment.
