What is the primary muscle of the forehead that Botox is injected into?

The primary muscle of the forehead that Botox is injected into is the frontalis muscle. This muscle plays a crucial role in forehead movement, particularly in raising the eyebrows and creating horizontal lines on the forehead. When Botox is injected into the frontalis, it helps to temporarily paralyze the muscle, thereby reducing the appearance of fine lines and wrinkles caused by muscle contractions.

The corrugator muscle, while involved in creating vertical frown lines between the eyebrows, is not primarily associated with forehead movement. The temporalis muscle is located on the side of the head and is involved in chewing, rather than facial expression. The orbicularis oculi is involved in closing the eyelids and does not primarily affect the forehead area. Thus, the frontalis is the key muscle targeted in forehead treatments with Botox.