Botox Therapy: Anatomy of the Face

Facial Anatomy

The Upper Third of the Face
The eyebrow is an important part of facial appearance. In females, it should curve above the bony rim over the eye about ½ inch with the highest point over the outside corner of the eye. In males, the brow is at the bony rim above the eye and is more flat in shape. With age the brows droop. Botox can dramatically change the eyebrow position bringing either end up or down making one look happy, sad, or crazed.

The frontalis muscle is under the forehead and raises the brow.

The muscles of the upper third of the face

Double bellied frontalis muscle, Single bellied frontalis muscle

There are four muscles that pull the brow down, the procerus, the corrugator supercilii, the depressor supercilii, and the orbicularis oculi. The corrugator pulls the eyebrow in and down. Activity of this muscle creates vertical or angled lines between the eyes.

The corrugator muscle

The procerus is a narrow muscle that goes from the root of the nose up to the mid forehead. It causes horizontal wrinkles over the bridge of the nose. The depressor supercilii runs above the inside corners of the eye.

The procerus muscle The depressor supercilii muscle

The orbicularis oculi encircles the eye. It pulls the brow in and down causing a vertical fold in the middle of the brow especially in squinters. On the outside corner of the eye it causes Crow’s feet. Below the eye it helps raise the cheek.


Treatment of this muscle can be difficult. Misplaced drug can cause the upper eyelid to sag interfering with vision. It can make lower face wrinkles worse by allowing the cheek to droop. Also if Botox is injected into the lower eyelid, it can droop, opening the eye too much, and leaving the patient with the inability to close the eye. Therefore, the muscle tone of the lower lid must be tested with a snap test before injection. Also if the muscle under the eye is weakened too much, the underlying tissue can push out and create a swollen tired look.

The orbicularis oculi muscle and Crow’s
feet

The Midface Anatomy

The muscles of the mid and lower face

Treatments here affect wrinkles and folds around the mouth and asymmetry of the face. The levator labi superioris is a narrow muscle that runs along the side of the nose and connects to the corner of the mouth. It is a major cause of the nasolabial fold that runs from the nostril to the corner of the mouth. It helps raise the lip. Contraction of one side causes a sneer, while contraction of both sides creates bunny lines (angled folds along the side of the nose). A Botox injection just outside of the nostril can soften the nasolabial fold. It can decrease the elevation of the upper lip during a smile, so it is best for people with a gummy smile.

The Lower Third of the Face and Neck

The muscles of the lower face


Contraction of the depressor anguli oris muscle

Treatment can raise the corner of the mouth, smooth out pits in the chin and help hide neck bands. The orbicularis oris muscle surrounds the mouth. It is needed to speak and chew, push out the lips, pull the lips back, and move the corners of the mouth. Botox can treat the vertical wrinkles on the upper and lower lips, but too much can cause problems with the functions of the mouth. The depressor anguli oris runs from the jaw to the corner of the mouth. It pulls the mouth corner down. Botox injected into this muscle raises the mouth corner. The injections must avoid the depressor labii inferioris to avoid problems with eating and speaking and a disfigured smile.

Peach pit chin

The mentalis muscle creates a pitted texture of the skin over the chin. Botox will smooth this effect out.

The different distributions of the platysmal muscle

Neck bands

The platysma is a wide flat muscle that runs from the chest and collarbone up to the jaw and corners of the mouth. Sometimes bands form and stick out from the neck like ropes (Turkey neck). Botox can effectively treat these bands. Too much Botox can result in serious complications including difficulty swallowing, choking, and voice changes.