Indications

Neurotoxins are commonly used to treat the vertical lines between the brows. This is the only area currently FDA-approved for all BoNTA neurotoxins (Botox, Dysport, Xeomin).

Anatomic Considerations

The vertical lines of the glabella are produced by contraction of the paired corrugator supercilii muscles, and the horizontal lines are caused by contraction of the centrally located procerus muscle. The corrugators originate on the supraorbital ridge of the frontal bone and insert on the skin above the middle third of the eyebrow. The procerus muscle originates on the nasal bone and inserts onto the skin of the glabella or mid-forehead.

Although this anatomy seems straightforward, there are subtle anatomic variations that can be visualized during facial animation. We have noted two distinct patterns of corrugator positioning: either straight along the brow, or more vertically oriented in a V-shape. For this reason, the injector should not rely on only one technique in this area. The injector should “look through” the skin to imagine the location of the muscles and their contribution to the wrinkles produced during movement.

Injection Technique

Topical anesthesia may be used; however, this injection usually can be tolerated without anesthesia. Prior to injecting the patient, have the patient frown the brow. Attempt to look through the skin to determine the size, strength, and location of the procerus and corrugator muscles. Because the corrugator muscles insert laterally into the skin, the injector can visualize the dimpling of the skin to determine the lateral extent of the muscles.

Usual doses in this region are 20 to 30 BU (Botox units) or 50 to 80 DU (Dysport units), but injector experience with these treatments has shown that some patients can do well with as little as 10 units, and others (often men) may need substantially more.

Injections must be placed 1 cm above the superior orbital rim to reduce the risk of upper eyelid ptosis. Injections are placed in the muscle belly. Try not to “bump” the periosteum, as this occasionally can be associated with post-injection headache.