Cosmetic Management of Gummy Smiles with Botulinum Toxin A: A Review

Excessive gingival display, or “gummy smile,” occurs in up to 14% of adults and is associated with lip hyperactivity, dentoalveolar extrusion, or vertical maxillary excess. Botulinum toxin A (BTA) has emerged as a minimally invasive therapeutic option, but protocols vary widely and long-term data are limited. To critically evaluate the current literature on BTA in gummy smile management, focusing on classification systems, injection techniques, efficacy, safety, and comparative outcomes against conventional surgical and orthodontic treatments. A narrative review was performed using PubMed, MEDLINE, and Scopus (2000-2023) with the terms “gummy smile,” “excessive gingival display,” and “botulinum toxin.” Clinical studies, case series, and reviews addressing BTA use were included. Data were synthesized into thematic categories. BTA consistently reduced gingival exposure by 3 to 5 mm, with effects lasting 4 to 6 months. Three main injection strategies were identified: single-point (Yonsei), multi-point, and orbicularis oris (“lip flip”). Reported complications were rare and transient (mild asymmetry, lip weakness). Standardized protocols were lacking, with heterogeneity in dosing (2-5 units per site) and injection depth. Comparative studies suggested BTA is less durable than surgical approaches but offers superior patient acceptability and safety for mild to moderate cases. BTA provides reproducible, temporary improvement in gummy smiles with high safety and satisfaction rates. However, absence of consensus on optimal technique and limited long-term evidence highlight the need for standardized protocols and prospective multicenter studies.