What is a coronectomy, and why are wisdom tooth roots left behind?

If your dentist or oral surgeon says part of your wisdom tooth should stay in your jaw, it's natural to feel surprised. Why leave anything behind? In some cases, removing the roots could put a nearby nerve at risk. A procedure called a coronectomy removes the top of the tooth while leaving roots in place to help reduce that risk.¹ Your care team can walk you through why it may be an option for you. 

What you'll learn: 

• Why the position of wisdom tooth roots can change the treatment plan 

• How a coronectomy differs from a full extraction or a broken root tip 

• What happens to retained roots and why follow-up matters 

• Which changes after surgery deserve a call to your provider 

Schedule an appointment with an Aspen Dental provider to discuss your wisdom teeth and the next steps for your care. 

What is a coronectomy? 

A coronectomy removes the crown, or upper part, of a wisdom tooth and purposely leaves some of the root in the jaw. The surgeon separates the crown from the roots, then cleans the area and closes it with stitches.¹ 

With a full extraction, both the crown and roots come out. With a coronectomy, leaving roots is part of the treatment plan. Your surgeon should explain that plan before you agree to the procedure, including the benefits, risks and possibility of needing more care later.¹ 

Why can lower wisdom tooth roots pose a nerve risk? 

A nerve runs through the lower jaw and carries sensation from your lower teeth, lip and chin. If wisdom tooth roots sit close to it, taking out the whole tooth can sometimes injure the nerve and leave you with numbness.¹ 

You may hear your surgeon call it the inferior alveolar nerve. If imaging shows a close relationship between this nerve and a lower wisdom tooth that needs treatment, a coronectomy may be considered. It reduces the need to disturb the roots near the nerve, but nerve injury is still possible.²

That can feel like a lot to weigh. Ask your surgeon to show you the area on your images and explain what makes your situation different from a routine extraction. 

How does your provider decide whether to leave roots? 

Your provider examines your mouth and reviews dental images.¹ They may use a 3D scan, called cone-beam CT, when more detail about the roots and nearby structures would help with planning, though experts are still working out exactly when it helps most.² Not every case needs one.³ 

The discussion should cover: 

• What problem needs treatment 

• What the images show about the roots and surrounding structures 

• Whether the tooth and roots are healthy enough to remain 

• What follow-up would involve if roots are left in place 

A coronectomy isn’t used when the wisdom tooth or its roots are decayed or infected.¹ Be sure to mention any pain, swelling or previous infections, even if the tooth feels fine at your appointment. 

Is a broken root tip the same as a coronectomy? 

No. During an extraction, a root tip can break before it comes out. That's different from planning to remove only the crown. 

The provider then weighs whether retrieving the fragment could do more harm than leaving it. Risks to nearby nerves, neighboring teeth or the sinus can influence that decision. Some stable root fragments from teeth with living pulp can remain when the wound can close appropriately, while infection or other disease may make removal necessary.³

If you've been told a fragment remains, ask what was left, why and how it will be monitored. Hearing “a root is still there” doesn't give you the whole picture, and you deserve a clear explanation. 

What happens to wisdom tooth roots after a coronectomy? 

Retained roots can move over time, and some people need them removed later.¹^,² Follow-up helps your provider keep track of healing and any changes.¹ Root movement doesn’t automatically mean another surgery is needed.² 

Keep the follow-up appointments your surgeon recommends, even if you're feeling better. Before you leave, make sure you know when to return, whether more images are planned and who to contact if something changes. 

Some soreness and swelling are expected after a coronectomy.¹ Follow your team's instructions for cleaning, food, activity and pain relief.⁴ Understanding tooth extraction healing can help you prepare, but your surgeon's instructions should guide your coronectomy recovery. 

When should you call after wisdom tooth surgery? 

Call your treating provider if you have: 

• Swelling that keeps growing after the first three days 

• Pus draining from the surgical site 

• Bleeding that continues even after you’ve followed your team’s gauze instructions 

• Severe pain that doesn’t ease with the medication your team recommended 

• Trouble breathing or swallowing 

• A fever⁴ 

Also let your surgeon know about numbness or any other change in sensation that lasts longer than you were told to expect.¹ If you're unsure whether something is part of healing, call and describe what you're noticing. 

To discuss your wisdom teeth or a recommendation you've received, schedule an examination with your local dental provider.

What is a coronectomy, and why are wisdom tooth roots left behind? FAQs 

Can the plan change during a coronectomy? 

Yes. If the roots start to shift while the tooth is being worked on, your surgeon may take them out instead.¹ It helps to raise that possibility beforehand so you understand how your care team would handle a change in the plan. 

Will I be awake during the procedure? 

That depends on your anesthesia plan. The area is numbed so you’re comfortable, and some providers also offer a sedative to help you stay relaxed.⁴ Let them know if you're nervous, and ask about preparation, transportation home and what you may feel during treatment. 

Can retained roots stay in place for years? 

They can, with monitoring. Studies of coronectomy have followed patients for years, and retained roots can move over time, so your surgeon and dentist keep an eye on them and may recommend removing them later.¹^,² Your provider can explain what monitoring makes sense for the roots left in your case. 

What if an infection develops later? 

Contact your surgeon. If an infection develops around the roots left behind, the surgeon will need to take them out and clean the surrounding area.¹ Your care team can explain what treatment involves and how to care for the area afterward. 

Sources 

¹ American Association of Oral and Maxillofacial Surgeons: “Coronectomy: A Solution to Wisdom Tooth Problems.” https://myoms.org/what-we-do/wisdom-teeth-management/coronectomy-a-solution-to-wisdom-tooth-problems/ 

² American Association of Oral and Maxillofacial Surgeons: “White Paper on Third Molar Data.” https://aaoms.org/wp-content/uploads/2024/03/white_paper_third_molar_data.pdf 

³ National Institutes of Health, StatPearls: “Oral Surgery, Extraction of Roots.” https://www.ncbi.nlm.nih.gov/books/NBK589696/ 

⁴ Cleveland Clinic, Health Library: “Wisdom Teeth Removal.” https://my.clevelandclinic.org/health/treatments/22119-wisdom-teeth-removal