Ideal Dose and Injection Site for Gummy Smile Treatment with Botulinum Toxin-A: A Systematic Review and Introduction of a Case Study

: The objective of this article is to review ideal injection point and ideal dose of botulinum toxin-A injections to treat different types of gummy smile, and to present a case treated with the recommended method. An electronic search of literature was carried out by using PubMed, Embase, and Google Scholar. Reference lists of studies were also hand-searched for relevance. According to inclusion and exclusion criteria, five prospective studies with 135 subjects were included in this systematic review. Injection of botulinum toxin-A is a noninvasive and temporary treatment option for gummy smile, and the Yonsei point is a safe and reproducible injection point for treatment by practitioners of all types of gummy smile.