Epicranius muscle

The terms epicranius muscle and occipitofrontalis muscle, are often used interchangeably in the literature. However, there is a distinction between how these terms have been used historically.

Epicranius literally means 'upon the cranium'. It is a broad composite musculofibrous complex covering the scalp and traditionally includes:

• Occipitofrontalis (frontalis and occipitalis bellies)

• Epicranial aponeurosis (galea aponeurotica) connecting the two bellies

• Sometimes also includes small associated muscles such as the temporoparietalis.

So, the epicranius can be viewed as the entire musculature of the scalp acting together, whereas occipitofrontalis refers specifically to the paired muscular component of the epicranius— composed of the frontalis (anterior) and occipitalis (posterior) bellies, joined by the epicranial aponeurosis.