The Coronectomy Procedure
Technique and rationale
A coronectomy procedure is a specialized surgical technique designed to balance the need for wisdom tooth management with the preservation of nerve function. This page explains the concept and rationale behind the surgery.
What is the procedure?
The dental coronectomy is a partial tooth removal. The surgeon removes the crown (the visible part of the tooth) and intentionally leaves the roots embedded in the jawbone. The overlying gum is then sutured closed.
✦ Key point: Only the crown is removed — the roots are left undisturbed to protect the nearby inferior alveolar nerve.
Why choose this technique?
The decision is made pre‑operatively when imaging (panoramic X‑ray or CBCT) reveals a high‑risk relationship between the tooth roots and the inferior alveolar nerve. By not manipulating the roots, the risk of direct nerve damage drops significantly — from roughly 7‑10% in high‑risk full extractions to less than 2% with coronectomy.
The surgical concept
While every case is unique, the general concept of the coronectomy technique follows these principles:
- Exposure — A small incision in the gum creates a flap, exposing the tooth and surrounding bone. Occasionally a tiny amount of bone is removed to access the crown.
- Sectioning — Using a sterile surgical drill, the tooth is carefully cut horizontally at the crown‑root junction (cementoenamel junction). This separates the crown from the roots.
- Crown removal — The crown is elevated and removed. The roots are left completely undisturbed in their original position.
- Confirmation & closure — The surgeon checks that the roots are stable and smooths any sharp edges. The gum is then sutured closed over the retained roots.
No surgical step‑by‑step instructions — this is a conceptual overview for patient education.
Key distinction: coronectomy vs. extraction
Complete removal
- Aims to extract entire tooth (crown + all roots).
- Carries higher risk when roots are entangled with nerve.
- May lead to permanent lip/chin numbness.
Nerve‑sparing
- Removes only the crown; leaves healthy roots.
- Accepts inert root remnant to avoid major nerve injury.
- Risk of nerve damage <2% in high‑risk cases.
Why leave roots behind?
By leaving the roots, the surgeon acknowledges that a small, stable remnant is a far better outcome than a major, permanent nerve injury. The retained roots typically become encased in healthy bone and remain asymptomatic for life. This makes the tooth coronectomy a valuable, conservative tool in modern oral surgery — it’s a planned trade: accepting a minor, manageable risk (root migration or very rare infection) to avoid the significant, life‑altering risk of nerve damage.
When is it indicated?
A coronectomy is specifically considered for lower wisdom teeth that are otherwise healthy (no active infection, cysts, or tumours) but show clear radiographic signs of close nerve proximity — such as darkening of the root where it crosses the nerve canal, or deflection of the canal.
It is not recommended if the tooth itself is non‑vital (dead) or if there is an existing infection at the root tip.
Educational purpose: This description is intended to help patients understand the rationale and general flow of a coronectomy. Always discuss the specific risks, benefits, and alternatives with your oral surgeon.