Concrescence is an uncommon condition where the roots of two neighbouring teeth are joined together by cementum, the hard layer that covers the root, while the inner parts of the teeth stay separate. It usually causes no symptoms and is often discovered by chance on an X-ray, or only when a tooth is being removed. The main reason it matters is that joined roots can make an extraction more complicated, so identifying it beforehand helps a dentist plan safely. It is most common at the back of the upper jaw.
Key takeaways
- Concrescence is a union of two tooth roots by cementum only.
- The dentine and pulp inside each tooth remain separate.
- It is uncommon and usually causes no symptoms.
- It occurs most often between upper back molars.
- It matters most when one of the teeth needs to be extracted.
How concrescence differs from fusion
It is easy to confuse the ways teeth can be joined, but they are distinct. Concrescence involves only the outer cementum of the roots joining, whereas fusion and gemination involve the dentine, the harder inner tissue, joining during development. Because concrescence is limited to cementum, the crowns of the two teeth look normal and separate in the mouth.
| Condition | What joins | Appearance |
|---|---|---|
| Concrescence | Cementum of the roots only | Two normal crowns, joined roots |
| Fusion | Dentine of two tooth buds | One large or notched tooth |
| Gemination | One tooth bud tries to split | One wide tooth with a groove |
What causes concrescence
There are two main explanations, and both may play a part. During development, if two teeth form very close together with little space between the roots, the cementum can bridge the gap as the roots complete. Later in life, inflammation or trauma around a root can trigger extra cementum, called hypercementosis, which can join a root to its neighbour. This is why concrescence can be present from a young age or develop later.
How it is found
Because the crowns look normal, concrescence is usually silent. It is most often found in one of two ways: seen on a routine X-ray, where the roots appear joined, or discovered during an extraction, when a tooth does not come away as expected. An X-ray helps distinguish true concrescence from teeth that are simply close together or overlapping in the image, so imaging is important before treatment.
Why it matters for extractions
The key issue is planning. If a dentist attempts to remove one tooth without knowing its root is joined to the next, the force can transfer to the neighbouring tooth, loosening it or the surrounding bone. Knowing about concrescence in advance lets the dentist plan a careful approach, which may include sectioning the teeth or a surgical technique to separate them safely. This is why a pre-extraction X-ray is valuable, especially at the back of the upper jaw where concrescence is most common, such as around developmental tooth variations.
Do you need treatment?
Concrescence itself needs no treatment. The teeth can be kept healthy with normal care, and many people never need to do anything about it. Treatment planning only becomes relevant if one of the joined teeth develops decay, infection, or needs removal for orthodontic or other reasons. In those cases the dentist uses imaging to plan the safest path. Keeping both teeth healthy with good daily care, as covered in our guide to preventing decay, is the best way to avoid complex treatment.
Frequently asked questions
Is concrescence harmful?
Usually not. It causes no symptoms and needs no treatment on its own. It becomes relevant mainly when one of the joined teeth needs to be removed.
How is concrescence diagnosed?
It is seen on an X-ray, which shows the roots joined by cementum. Sometimes it is only found during an extraction when teeth do not separate as expected.
What is the difference between concrescence and fusion?
Concrescence joins only the outer cementum of the roots, while fusion joins the inner dentine during development, often producing a single larger tooth.
Does concrescence make extraction dangerous?
It makes extraction more complex, not dangerous, when planned for. Knowing about it lets the dentist use a careful, often surgical, approach.
Can concrescence develop later in life?
Yes. It can be present from development or form later when inflammation or trauma triggers extra cementum that bridges two roots.
Speak with the team at Lumi Dental
If an X-ray has shown teeth with joined roots, the team at Lumi Dental in Melrose Park can explain what it means and plan any treatment carefully. Read more about general dental care or view current new-patient offers on the current deals page.
This article is general information only and is not a substitute for personal dental advice. Please see your dentist for advice about your situation.
