The duration of BoNTA's effect was based on the change in line severity at maximal contraction from week 1 to week 16 posttreatment.
The primary efficacy endpoint was physician-rated line severity at maximal contraction 4 weeks after treatment.
> The primary efficacy endpoint was physician-rated line severity 4 weeks after treatment at maximal contraction (frown).
Analysis of covariates indicated that at week 4, dose of BoNTA, line severity rating during maximal contraction and at resting position (both with baseline level subtracted), and subject-assessed line improvement were significantly (p < 0.001) related to subject satisfaction.
75 Responder rates at week 4 for each facial area were 100% at both repose and maximal contraction, with the exception of the crow's feet at maximal contraction (85%).
In another assessment, maximal contraction force was measured.
We made digital recordings at multiple sites at rest and with moderate and maximal contraction.
MVC remained unchanged (P=.45), and true maximal contraction forces decreased significantly (P=.04) on the nonoperated side.
MVC (P<.001) and true maximal contraction forces (P=.01) increased significantly on the operated side.
In these same tissues, maximal contraction to PE (10 µM) was reduced by ∼80%.
