Gummy smile
Why it happens, what the options are, and how to find the right treatment for your specific cause
You probably know exactly what bothers you about it. When you smile fully, especially in photos, more gum than you would like is visible above your upper teeth. The teeth look shorter than they should. The smile feels dominated by the pink tissue rather than the white of the teeth.
This is a gummy smile, and the experience of it is very consistent across patients. The causes, however, are not. Why gummy smile presentations develop varies considerably between individuals, and the reason this matters is that the treatment is different depending on the specific cause. A procedure that corrects a gummy smile from one cause does nothing for a gummy smile from a different one.
This article explains the main reasons a gummy smile develops, the treatment options that address each cause, and how a proper clinical assessment at Wollaston Dental Practice in Stourbridge establishes which of these applies to you before any treatment is recommended.
What makes a smile "gummy"?
The clinical definition of a gummy smile is showing more than 3 to 4mm of gum tissue above the upper front teeth when smiling. Below this threshold, the visible gum is considered within a normal aesthetic range. Above it, the proportion of gum to tooth changes in a way that many patients find aesthetically unbalancing.
The average amount of gum visible in a resting smile is around 1 to 2mm. The average amount visible in a full social smile (broadly smiling for a photograph, for example) tends to be somewhat more. Individual variation in what is considered attractive is wide, but most patients who describe a gummy smile are typically showing 4mm or more of gum in a full smile, and some significantly more.
The key is proportion. A full smile where the upper lip fully reveals the teeth with 1 to 2mm of gum at the margins looks balanced and natural. One where the upper lip rises to expose a band of gum several millimetres wide before the teeth even begin looks disproportionate.
Why gummy smile happens: the five main causes
The most important part of understanding a gummy smile is understanding what is causing it, because every treatment approach works on a specific underlying mechanism. Getting this wrong produces disappointing results.
1. Altered passive eruption
This is the most common cause of a gummy smile, and the one that is most frequently undertreated or misidentified.
During normal tooth eruption, the tooth pushes through the gum and the gum tissue progressively migrates to its final position at the neck of the tooth, exposing the full crown length. In altered passive eruption, this migration is incomplete: the gum tissue stays partially covering the crown, making the clinical crown (the visible part of the tooth) appear shorter than it actually is.
The underlying tooth is the correct length. The problem is entirely in the overlying gum tissue position. The tooth enamel is partly buried beneath gum that should have migrated away from it.
This is clinically significant because it means the treatment is straightforward and produces excellent results: a procedure to reposition or remove the excess gum tissue (crown lengthening or gingivectomy) reveals the tooth that was always there. The result is an immediate, permanent improvement in the tooth-to-gum proportion.
Gum treatment that addresses altered passive eruption is one of the most satisfying clinical procedures precisely because the outcome is visible immediately and does not require restorations or orthodontics to complete the result.
2. Vertical maxillary excess
This is a skeletal cause of gummy smile: the upper jaw (maxilla) is longer than average in the vertical dimension. When the mouth opens and the lips move into a smile position, more of the jaw is exposed than in a normally proportioned face, bringing more gum into view.
Vertical maxillary excess is a structural feature, not a soft tissue or tooth-position problem. The treatment for a significant vertical maxillary excess is orthognathic surgery: jaw surgery performed in hospital, typically in conjunction with orthodontic treatment, to reposition the maxilla at the correct vertical height.
For mild vertical maxillary excess, the gummy appearance can be improved by soft tissue procedures that reposition the upper lip (lip repositioning surgery) or by botulinum toxin injection to reduce the resting position of the upper lip muscles, reducing the height the lip achieves during smiling.
3. Hyperactive upper lip
In some patients, the upper lip rises higher during smiling than the facial anatomy would typically allow. The levator labii superioris and levator labii alaeque nasi muscles, which lift the upper lip when smiling, can have an unusually large range of action, pulling the lip well above the expected position.
The teeth and gum tissue may be entirely normally proportioned: the problem is that the lip reveals them excessively.
The most effective treatment for hyperactive upper lip is botulinum toxin (commonly known as Botox) injected into the muscles responsible for elevating the lip. This temporarily reduces the range of muscle contraction, limiting how far the lip rises during smiling. The effect lasts approximately three to four months and requires repeat treatment to maintain.
For patients who want a permanent solution, lip repositioning surgery (modifying the muscle and mucosal attachment at the base of the upper lip to limit its upward movement) produces a lasting result, though the degree of correction is more conservative than the temporary Botox effect.
4. Short upper lip
A naturally short upper lip that rests higher on the face allows more of the upper gum to be visible even during a partial smile, without any abnormality in the teeth, gum or jaw. This is an anatomical variant rather than a disease process.
Treatment options overlap with those for hyperactive upper lip: botulinum toxin, lip repositioning, and in some cases corrective cosmetic surgery. Orthodontic tooth movement sometimes helps by altering the position of the upper front teeth relative to the lip, providing slightly more coverage.
5. Dental compensation and tooth position
Where the upper front teeth are tilted outward (proclined) or are in a position that causes the gum above them to sit lower, orthodontic treatment to reposition the teeth can change the relationship between the gum margin and the lip line.
Clear aligner orthodontic treatment is one of the options assessed in these cases: if the position of the teeth is contributing to the appearance of the gummy smile, aligner treatment that moves the teeth into a better position may improve the proportions without any surgical intervention. This is discussed in detail during the clinical assessment, where photographs, bite analysis and sometimes X-rays are used to evaluate whether orthodontic tooth movement would produce a meaningful improvement.
A guide to causes and treatments
Most gummy smile presentations involve a combination of factors rather than a single pure cause, which is why clinical assessment before deciding on treatment is not a formality: it is the step that determines whether the treatment chosen will actually address the problem.
The treatments in more detail
Crown lengthening and gingivectomy
These are the two principal surgical procedures for correcting altered passive eruption. Both involve removing excess gum tissue to expose more of the natural tooth crown beneath.
Gingivectomy removes gum tissue at the margin level: the portion of gum covering the tooth surface is excised, revealing the tooth beneath. It is appropriate where the bone level is also correctly positioned and the problem is purely a gum tissue excess.
Crown lengthening additionally reshapes the underlying bone: if the bone crest is too high as well as the gum tissue, removing only the gum without addressing the bone will result in the gum tissue growing back to its previous position within a few months. Crown lengthening removes both the excess gum and the excess bone, creating a permanently altered position for both.
Healing takes six to eight weeks for full soft tissue maturity. Once healed, the improved tooth-to-gum proportion is permanent.
Both procedures are carried out under local anaesthetic and are straightforward outpatient treatments.
Botulinum toxin for hyperactive upper lip
Botulinum toxin (Botox) injected into the levator labii muscles reduces their contractile force, limiting the height the upper lip reaches when smiling. The effect develops fully over approximately seven to fourteen days and lasts three to four months before muscle function gradually returns to baseline.
For patients who want to assess the result before committing to a permanent procedure, botulinum toxin provides a reversible preview. For patients whose gummy smile is primarily caused by hyperactive lip muscles rather than a structural or tissue cause, this is often the most conservative and effective approach.
At Wollaston Dental Practice, facial aesthetics including botulinum toxin treatment is not available as part of the cosmetic treatment portfolio yet.
Clear aligner treatment
Where the position of the upper front teeth is contributing to the appearance of the gummy smile, orthodontic tooth movement is assessed as part of the treatment plan. Clear aligner treatment can reposition teeth that are proclined, tilted or positioned in a way that changes the lip-gum relationship.
Orthodontic treatment as part of a gummy smile correction is most commonly indicated in conjunction with other treatment, as a preparatory step before surgery or as the primary treatment where tooth position is the dominant cause. Whether it would produce meaningful improvement in your specific case is determined by the clinical assessment.
Composite bonding and porcelain veneers
Where altered passive eruption has produced teeth that look short and stubby, and crown lengthening is either not indicated or not chosen, cosmetic restorations can improve the appearance by adding material to the teeth to make them look longer. Composite bonding adds tooth-coloured resin to the edges and surfaces; porcelain veneers cover the entire visible tooth surface with ceramic.
These approaches address the appearance of the tooth proportion rather than the underlying cause. They are appropriate for patients who want a conservative cosmetic improvement or as a final step after crown lengthening to achieve optimal aesthetics.
Getting the diagnosis right: why assessment matters
The table above shows why correctly identifying the cause of a gummy smile matters so much. Gingivectomy on a patient whose gummy smile is caused by hyperactive upper lip muscles produces no improvement. Botulinum toxin injections on a patient with altered passive eruption change nothing about the tissue position. Orthodontic treatment for a patient with significant vertical maxillary excess provides minimal correction.
A proper clinical assessment at Wollaston Dental Practice includes photographs taken in natural smiling position, measurement of the gum-to-tooth ratio, assessment of the lip mobility at rest and on smiling, evaluation of tooth position and the underlying bone anatomy. Sometimes diagnostic X-rays or a lateral cephalometric radiograph (which shows the full facial skeleton in profile) are needed to evaluate the skeletal component.
This assessment takes time. It is not a two-minute look. But it is the step that determines whether the recommended treatment will actually produce the result you are hoping for.
Dr Mohammed Ihsan GDC No. 304200, who holds a Master’s in Dentistry from the University of Szeged and is currently pursuing a postgraduate diploma in oral surgery and implantology as a member of the Association of Dental Implantology, brings a surgical understanding of the oral and facial structures to every cosmetic consultation. The assessment of a gummy smile is not purely cosmetic: it is a clinical evaluation that requires anatomical understanding of the teeth, gum, bone and facial musculature.
Maintaining the result: the role of ongoing care
For gummy smile corrections that involve surgical or gum treatment, maintaining the result long-term requires that the gum tissue itself remains healthy. Gum disease, recession or tissue changes from ongoing inflammatory disease can alter the result of any surgical procedure over time.
Regular dental hygienist appointments maintain the health of the gum tissue around the corrected sites and allow early identification of any changes before they affect the aesthetic outcome. This is particularly important for patients who have had crown lengthening or gingivectomy: keeping the gum tissue in optimal health preserves the improved proportions that the procedure produced.
Dental check-ups at appropriate intervals allow the stability of the correction to be monitored and any changes to be identified and discussed.
The bottom line
Why gummy smile presentations occur is not a single-answer question. The five main causes, altered passive eruption, vertical maxillary excess, hyperactive upper lip, short upper lip and dental compensation, each require a different treatment approach. Identifying which cause applies to a specific patient requires a proper clinical assessment, not an assumption based on the appearance alone.
Treatment options range from straightforward, permanent gum tissue procedures to botulinum toxin, clear aligner orthodontics and, for the most significant skeletal cases, jaw surgery. Many patients benefit from a combination approach.
At Wollaston Dental Practice in Stourbridge, gummy smile assessment is carried out as part of a thorough cosmetic consultation. Full treatment fees are listed transparently on our fees page. Call us on 01384 438 143 or visit us at 27 High Street, Wollaston, Stourbridge, DY8 4NJ.
Disclaimer
The information in this article is intended for general educational guidance only and does not constitute personalised dental advice. Suitability for gummy smile treatment depends on individual clinical assessment by a qualified dental professional.
Wollaston Dental Practice is a private dental practice at 27 High Street, Wollaston, Stourbridge, DY8 4NJ, led by Dr Mohammed Ihsan GDC No. 304200, Master’s in Dentistry, member of the Association of Dental Implantology. We offer gum treatment, clear aligner orthodontic treatment, dental check-ups, dental hygienist appointments, dental implants, Invisalign, composite bonding, porcelain veneers, teeth whitening, dental crowns and smile makeovers. Call 01384 438 143.
Frequently asked questions
Why does my smile show so much gum?
Why gummy smile presentations develop depends on the specific cause. The most common reason is altered passive eruption: the gum tissue did not migrate fully to the base of the tooth crown during development, leaving the upper portion of the tooth covered. Other common reasons include a hyperactive upper lip that rises high on smiling, a naturally short upper lip, vertical maxillary excess (the upper jaw being longer than average), or the position and angle of the upper front teeth. A clinical assessment establishes which applies to your situation and what treatment would be effective.
Can a gummy smile be fixed without surgery?
In some cases, yes. Where the cause is a hyperactive upper lip, botulinum toxin is a non-surgical treatment that provides temporary but meaningful improvement. Where the cause involves the position of the teeth, clear aligner treatment may produce improvement. Composite bonding can address the appearance of shorter-looking teeth. However, where the cause is altered passive eruption with a high bone crest, or significant vertical maxillary excess, surgical procedures produce the most reliable results.
Is treatment for a gummy smile painful?
Surgical procedures for gummy smile, including crown lengthening and gingivectomy, are carried out under local anaesthetic and are typically well tolerated. Post-operative soreness for a few days is expected and managed with over-the-counter ibuprofen and paracetamol. Botulinum toxin injections involve a very fine needle and brief, mild discomfort at most. Gum treatment is carried out comfortably and the team at Wollaston Dental Practice takes the time to make every patient comfortable before any procedure begins.
How long do the results of gummy smile treatment last?
It depends on the treatment. Crown lengthening and gingivectomy produce permanent results that do not require repeat treatment, provided the result is maintained with good gum health. Botulinum toxin lasts three to four months and requires repeat treatment to maintain the effect. Clear aligner orthodontic results are maintained with retainer wear. All fees for treatment at Wollaston Dental Practice are listed on our fees page.
Will my gummy smile affect my dental health?
A gummy smile caused by altered passive eruption (where extra gum tissue covers part of the tooth) creates a slightly deeper gum crevice around the teeth, which can be harder to clean and more prone to gum disease. Patients with this presentation benefit from regular dental hygienist appointments to maintain gum health and reduce disease risk. Beyond this specific cause, a gummy smile is primarily an aesthetic concern rather than a health one, though the clinical assessment at a dental check-up rules out any underlying pathology.