What is coronectomy?

In the literature, coronectomy is also called intentional partial odontectomy. The crown of the impacted lower wisdom tooth, which faces the mouth, is cut just below the enamel–cementum junction and removed; the roots are left in place within the jawbone, still attached to the blood supply that nourishes them. The roots are not touched or moved, so the nerve next to the root is not manipulated either.

The technique is an intermediate solution chosen when “the nerve risk of removing the whole tooth is greater than the risk of leaving the roots”. Surgical textbooks recommend considering coronectomy for deeply impacted teeth and for older patients with a high suspicion of nerve injury.

Why is coronectomy considered instead of full extraction?

The inferior alveolar nerve supplies sensation to the lower lip and chin and runs just below or beside the roots of the lower wisdom tooth. If the roots touch the canal, narrow it, or the canal appears to pass through the root, the risk of the nerve being compressed or stretched increases when the whole tooth is removed.

Sources report nerve involvement after lower wisdom tooth surgery at rates ranging from 0.4% to 7.5%. Although most of these cases are temporary, permanent numbness can affect quality of life. The aim of coronectomy is not to touch the part in contact with the nerve at all, particularly in this high-risk group.

How is closeness to the nerve detected?

On a panoramic X-ray, the following findings may indicate a close relationship between the root and the nerve canal:

• Darkening of the root tip where it crosses the canal
• Narrowing or deviation of the canal at the level of the root
• Loss of the white line marking the upper border of the canal
• Narrowing or bending of the root at the level of the canal

When one of these findings is seen, a 3D cone beam CT (CBCT) scan is recommended. Structures that overlap on a 2D image may actually be shown on CBCT to lie next to each other towards the cheek or tongue; in that case, conventional extraction can still be planned.

Who is coronectomy suitable for?

• People with an impacted lower wisdom tooth whose roots are in close contact with the lower jaw nerve on CBCT
• Those whose tooth needs removal because of crown decay, recurrent gum inflammation (pericoronitis) or damage to the neighbouring tooth, but whose roots are healthy
• Older patients, in whom the risk of nerve injury is higher
• Very deeply impacted teeth where full extraction carries a predicted risk of jaw fracture (in selected cases)

Who is it not suitable for?

Coronectomy is not suitable for every tooth near the nerve. Certain conditions must be met for the retained roots to stay trouble-free:

• If there is inflammation, an abscess or a cyst at the root tip
• If the tooth is mobile; the roots may move when the crown is sectioned
• If the roots would later block orthodontic tooth movement or a planned restoration
• If the tooth is horizontal and the nerve is close to the crown (the nerve may be approached during sectioning)
• Situations where the risk of the retained root becoming a source of infection is unacceptable, such as severely immunocompromised patients or people who will receive or have received radiotherapy to the jaw

How is coronectomy performed?

1. Planning: The root–nerve relationship is assessed with CBCT, the options and risks are discussed with the patient, and written consent is obtained.
2. Anaesthesia: The procedure is usually done under local anaesthesia.
3. Access: The gum is lifted and bone around the crown is removed as needed.
4. Sectioning the crown: The crown is completely separated below the enamel–cementum junction and removed. The remaining root surface is trimmed to a few millimetres below bone level.
5. Closure: The area is rinsed and the gum is stitched to cover the roots.

Because the roots stay attached to living tissue, they may become covered with bone over time. The patient is always clearly informed that the procedure was a coronectomy and that the roots were intentionally left in place.

Coronectomy or full extraction?

What are the risks?

• Root migration: The retained roots may move upwards over time, away from the nerve. This is usually not a problem; however, if a root emerges into the mouth, it can be removed with a simpler procedure because it is now further from the nerve.
• Infection or painful healing: In a small number of patients, inflammation may develop around the retained root and the roots may need to be removed.
• Dry socket and swelling: Can occur, as with any wisdom tooth surgery.
• Nerve risk is not zero: Coronectomy aims to reduce the risk; it cannot be said to eliminate it.

How is the decision for coronectomy made?

Coronectomy is not a standard procedure recommended in the same way to every patient. The decision takes into account why the tooth needs to be removed, the distance between the root and the nerve, the patient’s age and general health, any planned orthodontic or prosthetic treatment and the patient’s preferences. For some patients, regular monitoring without removing the tooth at all can also be an option; this approach can be discussed especially for teeth that cause no complaints, show no signs of inflammation and lie completely within bone.

That is why the examination usually covers three options together: monitoring, full surgical extraction and coronectomy. After the possible short- and long-term outcomes of each have been explained, the decision is made together with the patient.

Recovery and follow-up after coronectomy

The first week is similar to a conventional wisdom tooth removal: mild to moderate swelling, pain lasting a few days and limited mouth opening can be expected. Aftercare rules are the same as for other extractions. Follow-up X-rays are usually taken in the first month, at one year and then at intervals recommended by your dentist. The position of the roots and the condition of the surrounding bone are monitored at these check-ups.

At Yayla Dental Akademi in Istanbul, wisdom teeth close to the nerve are assessed in 3D with CBCT; the options of full extraction and coronectomy are explained to the patient with their advantages and risks, and the decision is made together.

Frequently asked questions

Related pages

Medically reviewed by: Dr. Dt. Mehmet Fuat BozabaSpecialist in periodontology · September 2026

For appointments and information: Message us on WhatsApp or call 0544 289 66 33. Yayla Dental Akademi, Bahçelievler / Istanbul.

Sources: Abubaker AO, Benson KJ (eds). Oral and Maxillofacial Surgery Secrets. 2nd ed. Mosby Elsevier; 2007 · Miloro M, Ghali GE, Larsen PE, Waite PD (eds). Peterson’s Principles of Oral and Maxillofacial Surgery. 2nd ed. BC Decker; 2004 · Wayland J. Impacted Third Molars. 1st ed. Wiley-Blackwell; 2018 · Fragiskos FD (ed). Oral Surgery. Springer; 2007.

This article is for information only; a diagnosis and treatment plan can only be made by a dentist after an examination.