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

Background: 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. Objectives: 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. Methods: 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. Results: 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. Conclusion: 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.