One of the causes is hyperactive muscle which elevates the upper lip. Occasionally, the gummy smile is also aggravated by a thin upper lip that further contributes to the problem by exposing the upper gum even more.
Gummy smile can be effectively corrected with the use of muscle relaxant injections to reduce the activity of the muscle that elevates the upper lip when smiling.
Elevation of the upper lip will gradually become less and your new smile is transformed! You will be showing less gum and have much more confidence to smile without inhibition.