The Quantitative Effect of Botulinum Toxin A Over Brow Height

Abstract

Botulinum toxin type A (BTX-A) is currently used in temporal brow lifting. Reducing the activity of the superolateral portion of orbicularis oculi muscle causes lateral brow elevation. The objective of this study was to determine the quantitative brow elevation after paralysis of the superolateral portion of orbicularis oculi muscle. This study includes 10 female patients. Six units of BTX-A were injected into the superolateral portion of the orbicularis oculi in a serial manner into 3 points, below the lateral half of the brow at each side. Bilateral measurements were obtained by using calipers, immediately before and 2 weeks after the treatment. The medial canthus to the medial brow margin (AB), the lateral brow margin to the lateral canthus (CD), the medial brow margin to the lateral brow margin (BC), the brow apex to upper lid margin at the level of the lateral limbus (EF), the brow apex to the medial brow margin (EB), the brow apex to the lateral brow margin (EC), and upper eyelid margin to lower eyelid margin at the level of the pupil (GH), were measured. There were no statistically significant differences found between pretreatment and posttreatment left and right measurements. There were statistically significant increases in CD, EF, and GH measurements, which are point out brow elevation. There were no statistically significant differences found in other measurements. Same doses of BTX-A application did not disrupt symmetry. Applications of 6U BTX-A to the superolateral portion of orbicularis oculi provide brow elevation and increased interpalbebral distance and upper eyelid distance. Our study has confirmed that BTX-A treatment of superolateral portion of the orbicularis oculi muscle produces quantitative temporal brow elevation.