Three injection points in the treatment of glabellar lines with botulinum toxin - effective, safe and anatomically sound?

 

 

Three instead of five injection points in the treatment of glabellar lines with the neuromodulator botulinum toxin – effective, safe and anatomically sound?

 

Current treatment regimens for glabellar lines using the neuromodulator botulinum toxin are, in line with the prescribing information and existing publications, largely based on a five- or seven-point injection technique. Possible adverse effects include eyebrow ptosis and elevation of the lateral eyebrows (“Mephisto sign”/“Spock eyes”).

In a recently published study, Cotofana et al. (June 2021) investigated the efficacy and safety profile of a 3-point injection technique (Fig. 1) in the treatment of horizontal and vertical glabellar lines.

 

 

Fig. 1: 3-point injection technique – glabella

 

 

For this purpose, a total of n=105 patients (27 men and 78 women; mean age: 40.90 ± 9.2 years) were recruited for the study. Anatomically, only the attachments of the corrugator supercilii muscle and the procerus muscle were to be injected. Onset of effect and efficacy (up to 120 days post-injection) were then assessed using the so-called 5-point glabellar line severity scale. Depending on the study centre, treatment was carried out with onabotulinumtoxin (n=16; Allergan), incobotulinumtoxin (n=23; Merz Pharma) or abobotulinumtoxin (n=66; Galderma).

 

 

What were the findings?

• On average, onset of effect was 3.5 ± 1.5 days
• The duration of effect was up to 4 months
• There was no statistical significance with regard to the movement amplitude (= difference in eyebrow position at rest and on contraction of the frontalis muscle) of the medial and lateral portions of the eyebrows (Fig. 2). 
• Adverse effects such as eyebrow ptosis, upper eyelid ptosis or lateral frontalis muscle hyperactivity were not observed.

 

Fig. 2: Position of the eyebrows at rest and on contraction of the frontalis muscle – before and 14 days after injection using the 3-point injection pattern

 

 

Conclusion of the study:

• Greater consideration of anatomical landmarks in clinical practice can make treatments more effective and safer.
• The 3-point injection technique for treating glabellar lines with the neuromodulator botulinum toxin has a very good safety profile, and a duration of effect of up to 4 months has been demonstrated.

 

 

Source:

Cotofana et al. J Cosmet Dermatol . 2021 Jun;20(6):1625-1633. doi: 10.1111/jocd.14133. Epub 2021 Apr 16.