A gummy smile — clinically defined as 3mm or more of gingival (gum) tissue visible during a full smile — is most commonly caused by overactivity of the elevator muscles of the upper lip. In these patients, botulinum toxin injected precisely into the levator nasolabialis reduces the degree to which the upper lip elevates on smiling, bringing gingival display within a more aesthetic range.
Understanding the anatomy
Several factors can contribute to excessive gingival display, including a high zygomatic arch, vertical maxillary excess, and short upper lip length. However, the most common and treatable cause is overactivity of the lip elevator muscles — particularly the levator labii superioris alaeque nasi and the levator nasolabialis. When these muscles contract too forcefully on smiling, the upper lip rises higher than aesthetically desirable, exposing the gum line.
Botulinum toxin partially relaxes these muscles, reducing the amplitude of upper lip elevation without affecting the smile's natural shape or movement. The result is a lower, more controlled smile arc with reduced gingival exposure.
The goal is not to change your smile — it is to give you control over how much of it you show. A well-placed, conservative dose preserves natural expression while meaningfully reducing gingival display.
Who is best suited to this treatment
The patients who respond best to botulinum toxin gummy smile correction share several characteristics:
Hyperactive Levators
The primary indication. When the cause is muscular overactivity — rather than skeletal anatomy — botulinum toxin addresses the pathology directly.
Moderate Gummy Smile
3–6mm of gingival display offers the most predictable and natural outcomes. Greater display may require higher doses or a surgical referral.
Realistic Expectations
Treatment reduces — rather than eliminates — gingival display. Understanding the temporary nature of the result and the need for ongoing maintenance is important.
Trial Before Surgery
An excellent option for patients considering surgical correction who want to preview the aesthetic outcome, or those who prefer a non-surgical approach.
Starting Dose
2 units per side, superficially placed. Maximum 5 units per side. Always start low and assess at review.
Duration
Approximately 6 weeks — shorter than most anti-wrinkle treatments due to the high activity demands on these muscles.
Onset
Results typically apparent within 5–7 days. A review is scheduled at 2 weeks to assess response and refine if needed.
Considerations before treatment
Gummy smile correction is an effective but nuanced treatment. The muscles involved are small, active, and in close proximity to others that influence lip movement, speech, and eating. A careful assessment and conservative starting dose is essential.
Short Duration
Results last approximately 6 weeks. Ongoing maintenance is required to sustain the outcome — something worth factoring into your decision.
Cannot Be Reversed
Once placed, the treatment cannot be undone. Any unwanted effects must resolve naturally over 6–12 weeks.
Start Low
We begin with the minimum effective dose and reassess. It is always easier to add at review than to manage an overcorrection.
Potential risks
As with all botulinum toxin treatments, the risk profile is related to anatomy, dose, and technique. Specific risks with gummy smile correction include:
- Asymmetry — uneven lip elevation between sides; often correctable with targeted top-up at review
- Excessive lip drop ("Joker smile") — over-treatment producing a lip that descends too far; symmetrical but aesthetically undesirable
- Speech changes — temporary difficulty with certain sounds due to altered lip mechanics
- Eating difficulties — particularly with foods requiring a full lip seal
- Duration of side effects — any unwanted outcome resolves over 6–12 weeks as the toxin wears off
Two injection point approaches are used depending on the pattern and degree of gingival display. Both target the junction of the zygomaticus minor, levator labii superioris, and levator nasolabialis.
Customising for the Individual
- Pre-existing asymmetry — adjust dosing between sides to account for natural differences in muscle strength or resting position
- Deep nasolabial folds — add 1–2 units at the superior aspect of the nasolabial fold to achieve a fuller correction
- Lateral gingival display only — 2 units at the Yonsei Point plus 1 unit placed 10mm lateral to the Yonsei Point to address the lateral smile arc
Aftercare
Remain upright for four hours following treatment.
Smile and move your lips naturally — normal expression helps the toxin absorb appropriately.
Attend your 2-week review so any asymmetry or undercorrection can be addressed promptly.
Apply pressure or massage the treated area for 24 hours.
Exercise strenuously or expose the face to excessive heat for 12 hours post-treatment.
Expect an immediate result — onset takes 5–7 days and assessment at 2 weeks is important.