Prospective study of the aesthetic effect of botulinum toxin a when injected into the muscles of facial expression

ABSTRACT

Botulinum neurotoxin A (BoNT-A) causes an anticholinergic effect on neuronal fibers, which control muscle contraction and autonomic disorders. Thus, it has been widely used in facial aesthetics, decreasing the action of motor muscles and consequent wrinkles. This preliminary study evaluated the effect of BoNT-A in 77 patients, the treatment satisfaction index was defined in percentage (from 0% to 100%). The evaluation was carried out on 15th, 30th, 60th, 90th, and 180th days after BoNT. The data were analyzed using the Friedman, Student t, Mann-Whitney test with t (alpha=0.05). The results showed that at 15th and 30th days the scores were similar in all muscles with high level of satisfaction and until 90th days the scores decreased significantly for Corrugator supercilii 79.38%, Occipitofrontalis 71.46%, Orbicularis oculi 70.43%; but the satisfaction was good. At 180 days, there was a drop in effectiveness in all treated muscles since the scores decreased significantly, showing low satisfaction by the participants. This study demonstrated that the BoNT-A had attested satisfaction effect by participants for up to 90th days, but at 180th days the satisfaction was low. In the comparative analyzes between women under 40 and over 40 years of age, there was no significant differences.