Novel Insights into Botulinum Toxin Therapy Using Dynamic 3-D Quantification of Targeted Strain Reduction
Novel Insights into Botulinum Toxin Therapy Using Dynamic 3-D Quantification of Targeted Strain Reduction
Goals/Purpose: Neuromodulation is a well-established treatment for dynamic rhytids. Neurotoxin treatment outcomes, however, have been poorly quantified, thereby limiting advances in anatomically-based treatment regimens. We have previously validated the use of dynamic 3-D imaging for facial strain quantification. The goal of this study is to quantify botulinum toxin efficacy using dynamic 3-D imaging.
Methods/Technique: Fourteen females (mean age = 44) were imaged using three-dimensional optical analysis (ARAMIS, Trilion, PA). Excursion of the forehead and glabella were measured dynamically during brow elevation and furrowing prior to and two weeks after the injection of 20 units of onabotulinumtoxinA (Allergan, Irvine, CA). Average and maximum strains were calculated and differences were calculated with Wilcoxon signed rank test, using STATA.
Results/Complications: During brow elevation, average strain in the frontalis decreased from 4.3% to 1.8% (p = 0.03), maximum strain decreased from 40.4% to 23.1% (p = 0.03). The average strain in the glabella decreased from 10.7 % to 5.0 % (p = 0.03) while maximum strain decreased from 57.4% to 34.2% (p = 0.04). During brow furrowing, average strain of the frontalis decreased from 9.12% to 1.7% (p= 0.009), maximum strain decreased from 41.9% to 15.5% (p= 0.04). Average strain in the glabella declined from 2.8% to 1.0% (p = 0.001), maximum strain decreased from 36.11% to 24.41 % ( p= 0.03)
Figure 1: Patient during brow furrowing prior to neurotoxin injection. Blue, green, yellow and red represent increasing amount of strain.
Figure 2: Patient during brow furrowing prior to neurotoxin injection. Blue, green, yellow and red represent increasing amount of strain.
Figure 3: Graph depicting amount of strain in the glabella during brow elevation per frame, before and after injection of neurotoxin.
Figure 3: Graph depicting amount of strain in the forehead during brow elevation per frame, before and after injection of neurotoxin.
Conclusion: We demonstrate a novel technique for objectively quantifying the effects of botulinum toxin using dynamic 3-D imaging. The application of this technology pre- and post-injection will advance our understanding of neurotoxin effects on specific anatomic sites and thereby have significant implications for the development of personalized, anatomically-based treatment regimens and minimizing complications.