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Eruption Cyst: Causes, Symptoms, and Treatments

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Medically Reviewed By Colgate Global Scientific Communications

The term “eruption cyst” sounds dramatic, but it’s not a serious condition. It’s something quite common for children to go through. 

So, what is this minor issue with the menacing name? Let’s break it down.

What Is an Eruption Cyst? 

One way to think about it is like a bruise that happens as a new tooth is trying to emerge from the gums. As the American Academy of Pediatric Dentistry (AAPD) describes, an eruption cyst is a bluish lump that can appear when a primary (baby) or permanent tooth is in the process of coming in. The lump forms when fluid accumulates between the part of the tooth that will first emerge and the special gum tissue around it. It happens most frequently with lower molars, although it can happen when any permanent tooth comes in. 

Eruption Cyst Causes 

The reason why eruption cysts happen is unknown, according to a study by MOPOCB

Some research suggests they're the result of early cavities, trauma, genetics, or a lack of space for the tooth to move into.  

What is known is the average age for an eruption cyst is seven years old. They typically occur in the first 20 years of a child or adolescent’s life. That’s not surprising, as it's when the primary teeth usually erupt. 


Eruption cysts are often painless, and the only sign your child has one may be the visible cyst in their mouth. Even X-rays might not detect these soft tissue lesions.  

In some cases, your child may experience a dull aching when chewing.  

Treatment of Eruption Cysts 

As the AAPD guidelines describe, an eruption cyst typically resolves on its own, and in most cases the new tooth will emerge easily through the fluid-filled lump.  

If the cyst does not rupture on its own or if it becomes infected, there’s an easy solution. The dentist will administer a local anesthetic, and painlessly make a small cut in the sac to help the tooth erupt. 

Although they may look abnormal, an eruption cyst is usually harmless and can be taken care of by your dentist or oral surgeon. The best way to stay on top of all your child’s dental issues, including eruption cysts, is with regular dental checkups. If you’re ever concerned about any symptoms or the appearance of a cyst, contacting your child’s dentist and coming to the appointment prepared with a list of questions is a great way to ease your nerves. 

Oral Care Center articles are reviewed by an oral health medical professional. This information is for educational purposes only. This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your dentist, physician or other qualified healthcare provider. 

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