An Approach for Gummy Smile Treatment Using Botulinum Toxin A: A Narrative Review of the Literature

Excessive gingival exposure (gummy smile) is a non-aesthetic condition characterized by excessive exposure of the gingiva during smiling. The most common cause of gummy smiles was reported to be the hyperfunction of the muscles of the upper lip. Previous reports showed that botulinum toxin (Botox) is effective in the treatment of gummy smiles with a reversible effect, rapid initial action, safe application, low risk, and satisfactory outcome. The effect of Botox is usually observed between one and two weeks. This study aims to review the recent updates and guidelines for gummy smile treatment using botulinum toxin. A literature review was conducted involving relevant studies discussing gummy smile treatment using botulinum toxin with no time restriction. The PubMed and Google Scholar databases were used to gather the most relevant studies. The initial screening revealed 62 studies, and after removing the out-of-scope studies, the final review included 28 studies. Botulinum toxin can be used effectively for the treatment of gummy smile caused by lip dynamics with rarely reported complications. However, the most observed limitation was the temporary duration, which was reported to range from four to six months, and the re-injection of botulinum toxin is usually needed.