Botox injection into the masseter muscles for facial/jawline slimming is an advanced treatment technique that can frequently give great results to aesthetically re-balance the shape of a face. If the Botox that was injected was a more dilute concentration, or if it was not placed in the lower and more lateral aspect of the muscle, it can potentially spread to some of the neighboring muscles of facial expression that would affect your smiling and dimples. The good news is that this effect is temporary. Unfortunately though, it will take some time for the treatment to wear off. It is possible that you may start to notice improvement in your smile and your dimples within a month or two, but the effects can potentially last up to 4 months,. Best, Dr. Gregory Lewen