I've had masseter botox injections over the course of a year to initiate atrophy of the muscle. As a result, it is possible to go for longer periods of time without requiring injections as frequently or needing as many units. In the case of a lip flip, does this still happen? My top lip curls inwards due to overactive muscular activity. Wouldn't a botox lip flip help to train the muscle over time, providing longer term relaxation with repeated injections (as in the case of masseters)?