Understanding Gummy Smile and the Role of Botulinum Toxin
A gummy smile—defined as an excessive display of gingival tissue (generally >3 mm of gum above the front teeth)—is most often caused by hyper‑contractility of the upper‑lip elevator muscles, especially the levator labii superioris alaeque nasi (LLSAN) and the levator labii superioris (LLS). By injecting a neurotoxin into these specific fibers, you temporarily weaken their pull, allowing the lip to settle lower and cover more of the gingival margin. The product is supplied as a 100‑unit vial of innotox 100u, which contains a pre‑measured amount of botulinum toxin type A in a liquid formulation ready for immediate use.
Pre‑Treatment Assessment
Before you schedule the procedure, a thorough evaluation is essential:
- Patient history: Screen for pregnancy, breastfeeding, neuromuscular disorders (e.g., myasthenia gravis), and known hypersensitivity to botulinum toxin.
- Clinical measurement: Quantify gingival display at rest and during a full smile using a ruler or digital caliper. Record the vertical height in millimeters.
- Photographic documentation: Capture frontal and lateral views under standardized lighting. These images serve as a baseline for outcome analysis and medico‑legal protection.
- Informed consent: Discuss expected results, possible side‑effects (e.g., bruising, asymmetry, temporary lip ptosis), and the need for a possible touch‑up.
Dosage Guidelines and Dilution
Innotox 100u comes as a sterile liquid; no reconstitution is required. The typical clinical dilution for facial aesthetic use is 2 mL of saline per vial, yielding 5 U per 0.1 mL. However, many practitioners prefer a slightly higher volume (2.5 mL) to achieve a finer control of the injected volume (4 U per 0.1 mL). The exact dose depends on the severity of the gummy smile.
| Severity (gingival display) | Primary target muscles | Recommended units per side | Total dose (both sides) |
|---|---|---|---|
| Mild (≤2 mm) | LLSAN | 2–3 U | 4–6 U |
| Moderate (2–4 mm) | LLSAN + LLS | 3–4 U per muscle | 8–12 U |
| Severe (>4 mm) | LLSAN + LLS + Zygomaticus minor | 4–5 U per muscle | 12–15 U |
These numbers are starting points; adjust according to muscle bulk, previous toxin history, and patient response. Never exceed 20 U total for the upper‑lip elevators in a single session.
Injection Technique
Accurate placement is the key to a natural‑looking result:
- Patient positioning: Have the patient sit upright with a neutral head position. Ask them to smile gently to visualize the dynamic lip line.
- Skin preparation: Clean the area with alcohol. Use a topical anesthetic if the patient is sensitive, though most tolerate the procedure without.
- Landmark identification:
- LLSAN: Located 3–5 mm above the nasolabial fold, at the level of the mid‑pupil.
- LLS: Approximately 5–7 mm lateral to the alar base, along the nasolabial line.
- Zygomaticus minor (optional): Mid‑point between the lateral canthus and the oral commissure, roughly 1 cm above the smile line.
- Needle selection: A 30‑G, 13 mm needle provides sufficient depth for the superficial muscle fibers.
- Injection depth: Insert the needle at a 90° angle until you feel slight resistance, then deliver the toxin into the sub‑cutaneous layer (≈2–3 mm below the dermis).
- Volume per point: 0.05–0.1 mL (≈2–4 U) per injection site. Distribute evenly to avoid focal over‑activity.
- Post‑injection: Apply gentle pressure with a gauze pad for a few seconds to limit bruising.
“The levator labii superioris alaeque nasi should be targeted 3–5 mm above the nasolabial fold, at the mid‑pupil line, to achieve a natural‑looking reduction of gingival exposure.” — ASDS Clinical Consensus, 2023
Post‑Procedure Care
- Activity restriction: Advise the patient to avoid strenuous exercise, saunas, and excessive facial manipulation for 24 hours.
- Ice application: Short bursts of a cold compress (10 min on, 10 min off) can reduce swelling and discomfort.
- Monitoring: Expect the initial effect within 2–3 days, with peak outcome at 10–14 days.
- Follow‑up appointment: Schedule a check‑in at 2 weeks to assess symmetry and decide if a touch‑up (typically 1–2 U per side) is needed.
Safety, Contra‑Indications, and Troubleshooting
- Contra‑indications: Known allergy to any botulinum toxin component, active infection at the injection site, pregnancy, or severe neuromuscular disease.
- Common side‑effects: Mild bruising, transient asymmetry, or a slight “lip drop” that usually resolves within a week.
- Management of asymmetry: If one side appears over‑corrected, a small dose (1–2 U) can be added to the weaker side at the follow‑up.
- Persistent gummy smile: In cases where the result is insufficient, consider adding a filler to the upper lip vermillion border or a surgical lip‑repositioning procedure.
Frequently Asked Questions
How long does the effect last? Most patients enjoy a reduction in gingival display for 3–4
