The comparison between intradermal injection of abobotulinumtoxinA and normal saline for face-lifting: a split-face randomized controlled trial.

[BACKGROUND] Botulinum toxin type A (BTA) has been approved for the treatment of strabismus, blepharospasm, muscle spasm, cervical dystonia, pain syndrome, glabella wrinkles, and severe primary axillary hyperhidrosis. Intradermal injection of BTA has been used off-label by many clinicians for the purpose of face-lifting effect. Few studies on onabotulinumtoxinA (ONA) demonstrated no clinical efficacy on face-lifting effect when comparing to normal saline solution (NSS). So far, there is no split-face comparison study on face-lifting effect of abobotulinumtoxinA (ABO).

[OBJECTIVE] To determine the face-lifting effect of ABO intradermal injection and NSS.

[METHODS] Twenty-two subjects with symmetrical faces on both facial expression and expressionless were randomly injected with ABO at 1:7 cc dilution (500 unit or one vial in 7 cc of NSS) on one side and NSS on the other side using intradermal injection technique. Standardized photographic documentation was obtained at baseline, and at 2 weeks after treatment. The face-lifting effect was graded by two blinded dermatologists using photographic comparison and rated by the patients. Side effects were also recorded at the end of the study.

[RESULTS] Face-lifting effect was demonstrated in 40.9% and 4.5% of patients with ABO and NSS, respectively. There was a statistically significant difference in face-lifting effect when comparing between ABO and NSS (P = 0.021). The face-lifting was reported in 50.0% of patients receiving ABO injection. The patients with oval-face shape tended to respond better with ABO (P = 0.046). The odd of face-lifting effect for patients aged younger than 32 was higher than patients aged older than 32 with the odds ratio of 7.9 and 95% confidence interval of 1.1-56.1. Facial asymmetry was found in 22.7% of subjects.

[CONCLUSIONS] This study demonstrated the face-lifting effect of ABO intradermal injection. Patients with oval-face shape and aged younger than 32 tended to respond better. Therefore, patient selection should be emphasized to improve efficacy of this technique.