Roughly one in ten adults shows more than three millimetres of gum above the upper teeth when they smile fully, and that is the rough point where a smile starts to read as gummy. A gummy smile is not a disease and it does not need treating for health reasons. It is a cosmetic concern, and a common one. The useful thing to understand first is that a gummy smile is a symptom with several possible causes, and the treatment that works for one cause does nothing for another.
Key takeaways
- A gummy smile usually shows three millimetres or more of gum tissue above the front teeth during a full smile.
- There are four common causes: short-looking teeth, a thin or overactive upper lip, teeth that have over-erupted, and the way the upper jaw is built.
- The right treatment depends entirely on the cause, so an accurate diagnosis matters more than picking a procedure.
- Options range from a simple muscle-relaxing injection through to gum reshaping, minor surgery, orthodontics, or in skeletal cases, jaw surgery.
- Many cases can be improved with conservative, lower-cost options, so it is worth asking what the least invasive route is for your situation.
What actually counts as a gummy smile
Dentists look at how much gum is visible between the upper lip and the edge of the teeth during a relaxed full smile. Up to about two millimetres of gum is considered well within the normal range and most people would not notice it. Around three to four millimetres starts to draw the eye, and more than that is what most patients mean when they describe their smile as gummy. The number on its own is less important than how it sits with your lip line, tooth shape and face, which is why an in-person assessment is the only reliable way to plan.
The one question that decides everything: what is causing the gum to show
Before any treatment is chosen, the cause has to be identified, because the same gummy appearance can come from very different sources.
Short-looking teeth (altered passive eruption)
Sometimes the teeth are a normal length but the gum has not receded to its mature position, so it covers more of the tooth than it should. The teeth look short and stubby and the gum looks generous. This is one of the most treatable causes.
An overactive or short upper lip
If the muscle that lifts the upper lip is strong, it can pull the lip up higher than average and expose more gum, even when the teeth and gums are perfectly normal. The smile may look fine at rest and only turn gummy on a big grin.
Over-erupted front teeth
If the upper front teeth have drifted down further than the rest, they can drag the gum line with them. This is often tied to a deep bite and may be better handled with orthodontics than with gum surgery.
The way the upper jaw is built (vertical maxillary excess)
In some people the upper jaw is simply longer in the vertical dimension, so the whole gum and tooth complex sits lower. This is a skeletal cause and the most involved to correct.
Treatment options at a glance
The table below shows the common options, the cause each one targets and general market cost ranges in Australia. These are indicative ranges drawn from public fee information, not a quote, and they vary widely by case complexity and provider.
| Option | Best suited to | How long it lasts | General cost range (AUD) |
|---|---|---|---|
| Muscle-relaxing injection (to the lip lift muscles) | Overactive upper lip | Around 3 to 4 months per treatment | $200 to $450 per session |
| Gum reshaping / laser gum contouring | Short-looking teeth from excess gum | Long lasting once healed | $500 to $2,000 for the smile zone |
| Surgical crown lengthening (gum and a little bone) | Short-looking teeth where bone sits high | Long lasting | $1,500 to $4,000 for a segment |
| Lip repositioning surgery | Overactive lip, for a more lasting result than injections | Often lasting, can partially relapse | $2,000 to $3,500 |
| Orthodontics (to intrude or align teeth) | Over-erupted teeth, deep bite | Permanent with retention | $6,000 to $9,000+ |
| Jaw surgery (orthognathic) | Skeletal vertical maxillary excess | Permanent | Hospital-based, assessed individually |
How a dentist plans gummy smile treatment
In my experience the planning matters more than the procedure. A careful assessment measures how much gum shows, checks the health and position of the gums, looks at tooth length and bite, and works out whether the lip, the gum, the tooth position or the jaw is driving the appearance. Photographs and sometimes an X-ray help map where the bone sits under the gum, which decides whether reshaping the gum alone is enough or whether a little bone needs to be adjusted too. Only then is a treatment chosen, and often the most conservative option that fully addresses the cause is the right one.
Conservative options worth asking about first
For a lip-driven gummy smile, a small muscle-relaxing injection is the least invasive starting point. It is temporary, which some people see as a downside and others use as a low-commitment trial before deciding on anything permanent. For short-looking teeth caused by excess gum, modern laser gum contouring can reshape the gum line in a single visit with a relatively quick recovery. These conservative routes do not suit every cause, but they are worth raising before moving to surgery.
When gum reshaping pairs with cosmetic work
Gum contouring is sometimes done as the first step before veneers or bonding, because a tidy, even gum line gives the cosmetic work a better frame. If you are already considering a cosmetic refresh, it is worth reading our guides on crowns versus veneers and the broader smile makeover process so the gum work and the tooth work are planned together rather than in isolation. If your concern is more about tooth shape or spacing, our pieces on gaps between the front teeth and composite bonding versus veneers may be more relevant.
What gummy smile treatment costs
Cost depends on the cause and the option chosen, which is why the ranges above are so wide. The cleanest way to get a real figure is a consultation where the cause is diagnosed and a written treatment plan with itemised fees is provided. You can see current consultation and cosmetic offers on our pricing page, and you are welcome to book a consult for a written quote tailored to your smile.
Frequently asked questions
Is a gummy smile bad for my health?
No. A gummy smile is a cosmetic feature, not a health problem, as long as the gums themselves are healthy. If the gum show is paired with red, swollen or bleeding gums, that swelling is the issue to treat first, and our guide on bleeding gums explains why.
Does fixing a gummy smile hurt?
Most options are done under local anaesthetic and are well tolerated. Laser gum contouring and injections involve minimal discomfort and a short recovery. Surgical crown lengthening and lip repositioning involve a little more healing time, which your dentist will talk you through.
Will the gum grow back after contouring?
When gum reshaping is planned correctly and the bone level is respected, the result is typically stable. Problems with regrowth usually trace back to cases where bone needed adjusting but only the gum was trimmed, which is why the assessment of where the bone sits is so important.
Can braces or aligners fix a gummy smile?
Sometimes. If over-erupted front teeth or a deep bite are the cause, orthodontics can move the teeth into a position that reduces the gum show. Our guide on straightening crooked teeth covers how aligners and braces work.
How long do the results last?
It depends on the option. Injections are temporary and need repeating every few months. Gum reshaping, crown lengthening, orthodontics and jaw surgery are intended to be long lasting or permanent. Lip repositioning can partially relapse over time in some people.
A gummy smile is one of the more satisfying cosmetic concerns to address because the right diagnosis usually points to a clear, often conservative solution. If it is something you have always been self-conscious about, the first step is simply finding out which of the four causes is behind it.
