Sometimes a dentist looks at a tooth and sees a problem that a crown or filling could fix, except there is not enough tooth showing above the gums to hold it securely. Other times, a person simply feels their teeth look short or their smile shows a lot of gum. In both situations, a procedure called crown lengthening may come up.
This guide explains what crown lengthening is, why it is recommended, how it is done, what healing usually involves and what questions are worth asking before you decide.
What is crown lengthening?
The American Academy of Periodontology (AAP) describes crown lengthening as a procedure that adjusts the gum and bone level to expose more of the natural tooth so it can be restored. Excess gum tissue, and sometimes a small amount of bone, is reshaped. It can be done on a single tooth or on several teeth at once.
The word "crown" here refers to the part of the tooth above the gumline, not only to a dental crown. The goal is to make more of that visible tooth structure available.
Why would I need crown lengthening?
There are two broad reasons: restorative and cosmetic.
Restorative reasons. A 2024 review in the journal Cureus describes functional crown lengthening as a way to expose decay or fractures that extend below the gumline. It can also help when a tooth has been worn down or broken so much that there is little height left to support a crown. Exposing more healthy tooth structure gives the new restoration a better surface to hold onto.
Cosmetic reasons. The AAP notes that some people have a "gummy" smile because their teeth look short, even though the teeth may actually be a normal length and are simply covered by extra gum tissue. Crown lengthening can expose more of the teeth and even out an uneven gumline.
Why not just place the crown below the gums?
The gums and bone need a small band of space around each tooth to stay healthy. Dentists often call this the biologic width. According to the Cureus review, this zone of attached gum tissue averages about 2 millimeters above the bone. When a filling or crown edge sits too deep and crowds into that space, the review explains, the body tends to respond with ongoing inflammation and can lose bone as it tries to reestablish that space.
Crown lengthening creates room so the edge of the restoration can sit where the gums and bone can tolerate it. That is why it is sometimes recommended before a crown rather than as a separate cosmetic choice.
How is crown lengthening done?
The approach depends on how much tooth needs to be exposed and where the bone sits. The Cureus review describes several options:
- Gum reshaping (gingivectomy). When there is enough distance between the gum edge and the bone, extra gum tissue alone can be removed.
- Gum flap with or without bone reshaping. When the bone is close to where the new gum edge needs to be, the gum is gently lifted so the dentist or periodontist can see the bone, reshape it if needed and reposition the gum at a lower level.
- Orthodontic extrusion. In some cases, a tooth can be slowly moved upward with orthodontic forces instead of removing gum and bone around it.
Your dentist will explain which approach fits your tooth and why.
How long does it take to heal before a crown?
Healing time varies with the technique. The Cureus review describes tissue maturation periods of about 4 to 6 weeks after gum reshaping alone and about 8 to 12 weeks when a flap is used and bone is exposed. When bone has been removed, the review notes that a longer wait of several months may be advised so the gums can settle into their final position.
This waiting period matters because gum tissue can creep back toward its earlier position as it heals. Giving the tissue time to stabilize helps the final crown or filling fit the gumline you will actually live with.
Is crown lengthening always the right choice?
Not always. The Cureus review lists situations where crown lengthening may be less suitable, including:
- A tooth whose root is short compared with the part above the gums, since removing bone could leave too little support
- Decay or a root fracture so extensive that the tooth cannot be reliably restored
- Back teeth where bone removal could expose the area where the roots divide
- Cases where reshaping bone could weaken support for the neighboring teeth
In some of these situations, the review notes that removing the tooth and replacing it, for example with an implant, may be considered instead. The right answer depends on the tooth, the surrounding gums and bone, and your goals, which is why an exam comes first.
Questions to ask your dentist
- Is this for a restoration, for appearance or both?
- Will the procedure involve gum only, or gum and bone?
- How long should I wait before the final crown?
- Are there other options for this tooth, and what are the tradeoffs?
- How should I care for the area while it heals?
Considering crown lengthening in Palo Alto?
If you have been told a tooth needs crown lengthening, or you are curious whether it could help your smile, a careful exam is the best place to start. You can learn more about our crown lengthening care, and our Palo Alto team is happy to talk through your options. If a tooth is painful, broken or getting worse, please do not wait to have it checked.
Book an appointment to discuss whether crown lengthening makes sense for you.
Sources
American Academy of Periodontology: Surgical Procedures
American Academy of Periodontology: Cosmetic Procedures
This article provides general education and does not replace an individual dental examination or diagnosis.
