In short: a gummy smile (showing too much gum when you smile) is a symptom with four possible causes: gum covering too much of the tooth, an upper lip that rises too far or is short, front teeth that have grown downwards together with their bone, or an upper jaw that is longer than it should be. When the cause is the bone, neither Botox, nor hyaluronic acid filler, nor a gingivectomy will correct it: the treatment is to move the upper jaw up with orthognathic surgery. That is why a diagnosis has to come before any treatment.
We often see patients who have spent years treating their gummy smile. Botox every few months, hyaluronic acid in the lip, a gingivectomy. And the gum is still there.
It is not bad luck. It is the wrong diagnosis. A gummy smile is a symptom, not a diagnosis, and each cause has its own treatment. When the cause is in the bone, no treatment on the gum or the lip will correct it.
Four causes that look alike and are not treated the same way
When you smile, the amount of gum you show depends on three structures: the tooth, the lip and the bone that holds them. If one of them is off, the visible result is the same (Garber and Salama, 1996). The treatment is not.
- Altered passive eruption. The gum has not fully receded from the tooth during development. The teeth look short and square, and the excess is gum. This is where periodontal (gum) surgery is indicated.
- Hypermobile or short upper lip. The upper lip rises more than usual when you smile, or it is short at rest. The problem is in the muscle or the soft tissue, and this is where botulinum toxin has its place.
- Dentoalveolar extrusion. The front teeth and the bone around them have grown downwards, often with a deep overbite. It usually needs orthodontics.
- Vertical maxillary excess. The whole upper jaw is longer than it should be. The lip and the gum are fine; they sit on bone that is too long. It is a skeletal problem.
It is common for several to coexist. That is why the diagnosis has to separate how much each one contributes before anything is proposed.
The combination that causes the most confusion is altered passive eruption with vertical maxillary excess. They are not the same thing: one is a problem of the gum on the tooth, the other is a problem of the bone. But they can happen together, and then each adds its share of visible gum. If only the gum is treated, the excess bone is still there. If only the upper jaw is moved up, the teeth can still look short and the gum can still show too much. In those cases we plan two stages, and the order is deliberate: the less precise step first, the finer one after. Bone surgery works in millimetres; gum and tooth surgery allows much finer adjustments. That is why the gum is adjusted last, on the final position of the upper jaw.
Why Botox, hyaluronic acid and gingivectomy are not enough
They are not bad treatments. They are treatments for other causes.
Botulinum toxin weakens the muscles that lift the lip. If the problem is a lip that rises too far, it works while the effect lasts, and then it has to be repeated (Polo, 2008). If the problem is a long upper jaw, the lip may rise less, but the face is still long. And a lip that barely moves changes the whole smile, not just the gum.
Hyaluronic acid in the lip tries to lengthen it or limit how far it moves. It adds volume to a structure that is not the one in excess.
A gingivectomy trims gum and lengthens the visible tooth. When there is altered passive eruption, it is the right treatment. When the excess is in the bone, the gum is not in excess: it is where it should be, on bone that is not. Trimming it has a biological limit, because the root of the tooth cannot be exposed.
The pattern we see is always the same: reasonable treatments applied without a diagnosis. The patient has not failed. They have been given the answer to a different question.
How we find out where it comes from
The diagnosis is not made by looking at the smile. It is made by measuring what lies behind it.
- At rest. How much tooth shows with the lip relaxed, and how long the upper lip is. A lip of normal length that shows too much tooth points to the bone.
- When smiling. How far the lip rises from its resting position. If it rises much more than usual, there is a muscular component.
- The tooth. The ratio between the length and width of the crown. Short, square teeth suggest the gum is covering too much of them.
- The whole face. The height of the lower third, the position of the chin, whether the lips close easily. Vertical maxillary excess rarely stops at the smile.
- The CT scan. It confirms the real position of the upper jaw and the roots, and it is the basis of the virtual planning if surgery is indicated.
With this information we know how much of the problem is gum, how much is lip and how much is bone (Dym and Pierre, 2020). And the treatment is decided by that split, not by the complaint.
When it is the bone: moving the upper jaw up
If the excess is skeletal, the treatment is to reposition the bone. This is a Le Fort I osteotomy with impaction: we separate the upper jaw and fix it in a higher position, so that the lip, which has not changed, now covers the gum it used to show.
This is not improvised in theatre. With the CT scan and facial records we carry out virtual planning before surgery and design custom guides, so the operation carries out a plan that has already been decided.
This is where we use our approach to minimally invasive orthognathic surgery (MIOS): access only from inside the mouth, no visible scars, and as little lifting of the soft tissue as possible. The aim is the same as in conventional orthognathic surgery. What changes is how much surgical trauma it takes to get there.
Moving the upper jaw up does not only affect the smile. By reducing the height of the lower third, the lower jaw rotates and the chin changes position. Sometimes that improves lip closure and the profile; other times the chin needs to be planned as well. That is why we study it as a problem of the whole face, not of the gum.
There is one particular case: a long upper lip. Orthognathic surgery corrects the bone, but it does not change the length of the lip. Once the upper jaw has been moved up, a long lip can cover more tooth at rest than it should. In those patients a second stage on the soft tissue is sometimes needed, a lip shortening procedure (lip lift), to bring the lip back to the right proportions. We do it some time after the orthognathic surgery, once the bone and the tissue have settled and we can measure the lip on its new base.
Not every gummy smile caused by the bone needs surgery. If the excess is mild and it does not bother you, the most honest option may be to do nothing. And when several causes coexist, surgery deals with the bone; the gum or the lip may need their own treatment.
Before the next treatment, a diagnosis
If you have been treating your gummy smile for a while without results, the useful step is not to try something else. It is to find out where it comes from.
Sometimes the answer will be the gum, and the treatment will be simple. Sometimes it will be the lip. And sometimes it will be the bone, and then it is worth knowing before you keep investing in solutions that cannot reach it.
Frequently asked questions
What is a gummy smile?
It means showing more gum than usual when you smile. It is not a diagnosis but a symptom with four possible causes: altered passive eruption, a hypermobile or short upper lip, dentoalveolar extrusion and vertical maxillary excess. Several often coexist.
Does Botox fix a gummy smile?
When the cause is a lip that rises too far when you smile, botulinum toxin reduces it while the effect lasts, and then it has to be repeated. When the cause is an upper jaw that is too long, it does not correct it: the lip rises less, but the face is still long.
Can a gummy smile be fixed without surgery?
It depends on the cause. A hypermobile lip is treated with botulinum toxin and dentoalveolar extrusion usually needs orthodontics. Altered passive eruption is corrected with periodontal surgery on the gum. Vertical maxillary excess can only be corrected by moving the bone; if it is mild and does not bother you, the most honest option may be to do nothing.
How do I know if my gummy smile is caused by the bone?
One sign is that too much tooth shows with the lip relaxed even though the lip is of normal length, and that the lower third of the face is tall. It is confirmed by measuring at rest and when smiling, assessing the whole face and with a CT scan, which shows the real position of the upper jaw and the roots.
What surgery corrects a gummy smile caused by the bone?
A Le Fort I osteotomy with impaction: the upper jaw is separated and fixed in a higher position, so that the lip covers the gum that used to show. It is planned virtually on the CT scan and carried out with custom guides, from inside the mouth and with no visible scars.
How much does gummy smile surgery cost?
At ARQÉA, upper jaw surgery (single-jaw) costs €6,500 and double-jaw surgery €12,000, with the anaesthetic and the surgical centre included. If the lip needs to be shortened afterwards, a lip lift costs €2,500. The final price is given at the consultation.
Does the lip need surgery as well?
Only in some cases. Orthognathic surgery does not change the length of the lip, and a long upper lip can cover more tooth than it should once the upper jaw has been moved up. A second stage to shorten the lip is then considered, some time later, once the bone and the tissue have settled.
How long is the recovery from orthognathic surgery?
The usual time off work is 3 to 4 weeks, and a little longer if your job is very physical or depends on your appearance. Walking and talking from the first day; intense exercise not before 4 weeks. For the first weeks the diet is blended.
References
- Garber DA, Salama MA. The aesthetic smile: diagnosis and treatment. Periodontol 2000. 1996;11:18-28. doi:10.1111/j.1600-0757.1996.tb00179.x
- Polo M. Botulinum toxin type A (Botox) for the neuromuscular correction of excessive gingival display on smiling (gummy smile). Am J Orthod Dentofacial Orthop. 2008;133(2):195-203. doi:10.1016/j.ajodo.2007.04.033
- Dym H, Pierre R. Diagnosis and treatment approaches to a "gummy smile". Dent Clin North Am. 2020;64(2):341-349. doi:10.1016/j.cden.2019.12.003
As we always say, this article is for general information and doesn't replace an individual medical assessment. Where your gummy smile comes from is decided at the consultation, by measuring what lies behind it.
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