Occipitofrontalis muscle: the frontal and occipital bellies
Quick facts
- Definition
- Scalp muscle with two bellies, frontal and occipital, joined by the galea aponeurotica.
- Function
- The frontal belly raises the eyebrows and wrinkles the forehead; the occipital belly moves the scalp backward.
- Innervation
- The frontal belly receives branches of the facial nerve (temporal); the occipital belly, the posterior auricular branch.
- Relevance in HOF
- It is the muscle behind forehead lines and eyebrow position.
The occipitofrontalis is a broad, thin muscle that covers much of the scalp. It has two separate bellies: the frontal, in the forehead, and the occipital, at the back of the head. Between them lies a fibrous sheet, the galea aponeurotica, which works as a "tendon" connecting the two parts. For that reason, current anatomical nomenclature treats it as a single muscle with two bellies.
How do the two bellies act?
When the frontal belly contracts, it raises the eyebrows and wrinkles the forehead skin, forming the horizontal lines. When the occipital belly contracts, it pulls the galea backward and steadies the scalp. The combined action is subtle, but it explains why the scalp can follow when the forehead moves.
In HOF, the focus is almost always the frontal belly, presented as the frontalis muscle. The forehead skin follows this movement and gives rise to the horizontal dynamic wrinkles.
Why does balance with other muscles matter?
The eyebrow is held by opposing forces. The frontalis pulls it up. The depressors (such as the corrugator, the procerus and part of the orbicularis oculi) pull it down. This balance defines the eyebrow position at rest and in expression.
That is why botulinum toxin treatment of the forehead has to be planned together with the glabella. If the frontalis is weakened carelessly, the brow can drop and the gaze can look heavy. If the frontalis is over-preserved, the lines remain. The decision belongs to the qualified professional, after assessment, and takes into account forehead height, prior ptosis and the activity of each muscle.
How to assess it at the consultation?
Recording the movement helps explain to the patient why forehead treatment calls for caution and why the result needs to preserve a natural look.
Relationship with glabella treatment
The glabella is the area between the eyebrows, worked by the corrugator and the procerus. Because the frontalis opposes these muscles, any change in the balance among them affects the brow. That is why the forehead and glabella are often assessed together.
In Harmy
The Glabella marking point simulates the effect of toxin in the area between the eyebrows, with the volume in the app's symbolic unit. The projection is illustrative, does not represent muscle dynamics, and the prompt forbids changing expression.
Also called: epicranius muscle, frontal and occipital belly.
Frequently asked questions
Are the frontalis and the occipitofrontalis the same muscle?
The frontalis is the anterior belly of the occipitofrontalis. In HOF, when people say frontalis muscle, they usually mean this belly, which is responsible for forehead lines.