A gummy smile — where more gum than tooth shows when you smile — is one of the most common cosmetic concerns I hear about at consultations. What most patients don't realize is that there are several different causes, and the correct treatment depends entirely on which one applies. Here's how to identify what's causing yours and what can be done about it.
What Counts as a "Gummy Smile"?
Generally, showing more than 3–4mm of gum tissue when smiling is considered excessive gingival display. Studies suggest about 10% of adults between 20–30 are bothered by a gummy smile. It's more common in women than men. While purely cosmetic, it significantly affects how confident people feel about their smile.
The 4 Main Causes — and Their Treatments
1. Altered Passive Eruption — Most Common Cause
During normal tooth development, gum tissue recedes as teeth emerge, exposing the full crown. In altered passive eruption, this recession doesn't fully occur — the gums stay partially covering the teeth, making them look short even though they're actually normal-sized underneath. The teeth aren't small; they're just hidden.
Dr. C reshapes the gumline using a soft-tissue laser or scalpel, removing excess tissue to expose the full tooth. The procedure takes 1–2 hours under local anesthesia. Results are permanent. Cost: $150–$350 per tooth. Often the only treatment needed — no veneers required if the underlying teeth are healthy and well-shaped.
2. Hypermobile Upper Lip
Some people have an upper lip that moves unusually high when smiling — more than average — exposing gum that would normally stay covered. The gum coverage and tooth length are actually normal; it's the lip movement that creates the appearance. This is a muscular/anatomical variation, not a dental problem.
Small amounts of Botox injected into the upper lip muscles reduce the muscle's range of motion, limiting how high the lip rises. Results last 3–6 months and require maintenance. Lip repositioning surgery offers a permanent alternative. Botox cost: $200–$400 per treatment.
3. Short Upper Lip
A naturally short upper lip exposes more of the gum when smiling because there's less tissue to cover it. The teeth and gums themselves are normal — it's the lip anatomy that creates the appearance.
Lip repositioning surgery can lengthen the upper lip. In some cases, crown lengthening combined with veneers can reduce the apparent gum-to-tooth ratio even without lip surgery. Dr. C will assess the specifics at your consultation.
4. Vertical Maxillary Excess (Jaw Overgrowth)
In some cases, the upper jaw grew too long vertically during development, causing the gums to sit lower than normal. This is the most structural cause and creates the most pronounced gummy smile — often combined with an open bite or other bite issues.
This requires surgical repositioning of the upper jaw by an oral and maxillofacial surgeon — beyond the scope of general dentistry. Dr. C can evaluate whether this is the cause and refer appropriately.
Crown Lengthening + Veneers — The Common Combination
The most common gummy smile treatment sequence at Frisco Dental Hub is crown lengthening followed by porcelain veneers. Here's why:
- Crown lengthening removes excess gum and exposes the full tooth structure
- The exposed teeth may be slightly uneven in shape from years of being partially covered
- Veneers then create uniform shape, ideal proportions, and perfect color across the smile zone
- The combined result is dramatic — balanced gumline, ideal tooth-to-gum ratio, complete smile redesign
Not every gummy smile patient needs veneers after crown lengthening — if the underlying teeth are well-shaped and well-colored, crown lengthening alone may produce a complete result. Dr. C assesses this at your consultation with digital smile design.
Find Out What's Causing Your Gummy Smile
Book a complimentary smile design consultation with Dr. C. He'll identify the cause and recommend the right treatment — including if the answer is simpler and less expensive than you expected.
Medically reviewed by Dr. Chakrapani Nannapaneni, DDS — UCSF School of Dentistry · ADA Member · Frisco Dental Hub, 4500 Hillcrest Rd Suite 190, Frisco TX 75035 · (972) 276-4888