Treatment of gummy smile using botulinum toxin

Abstract

Excessive gingival exposure refers to gingival exposure of more than 2mm when smiling and it is considered as non-aesthetical. Causes of excessive gingival exposure onset include delayed eruption of tooth, vertical maxillary excess, hypermobile upper lip, and short upper lip. Either prosthodontic, corrective, or surgical treatment can be used depending on the cause of its onset. Recently, the treatment method of excessive gingival exposure using botulinum toxin (BoNT) was introduced as non-surgical method. Since treatment method is yet to be standardized, there is controversy over the treatment method or effect.

Accordingly, the purpose of this study is to examine the role of BoNT as the treatment method for excessive gingival exposure and research guidelines for excessive gingival exposure research using BoNT in the future through literature review.

Online literature review was conducted via Pubmed, Scopus, and Web of science on April 1st, 2015. Keywords used for search were gummy smile, gingival exposure, or combination of gingival display with either botox, botulinum, onabotulinumtoxinA, or abobotulinumtoxinA. Thirty three literatures were searched as a result and 10 articles were used in this study excluding the 23 literatures that did not meet the inclusion criteria.

As a result of literature review, it was revealed that BoNT treatment for excessive gingival exposure is reversible and effective treatment and side effects followed by BoNT injection was minimal and temporary. Also, the satisfaction of patients toward the treatment is high and treatment effect lasts for at least 12 weeks. Since there are several limitations in this research, clinically significant result may be acquired when well designed randomized controlled trials are conducted in the future.