Does every wisdom tooth have to come out?
No. A wisdom tooth that is causing no symptoms, shows no disease on a radiograph, is not damaging the tooth in front of it, and is either cleanable or completely covered by bone is a tooth that can reasonably be left where it is and reviewed. A recommendation to remove a particular tooth comes with the reasoning for that particular tooth, stated against that tooth's film.
There are three courses of action rather than two. The third one — leaving the tooth alone — is frequently described as doing nothing, which is the wrong name for it. It is a plan with appointments, radiographs and defined triggers attached, and it is only defensible if those things actually happen.
- Removal. The whole tooth comes out, crown and roots, with bone removed and the tooth divided as the position requires.
- Coronectomy. The crown is removed and root structure is deliberately left in the jaw. It is a lower-jaw procedure, and the indication for it is narrow: roots that lie against the nerve canal.
- Monitored retention. The tooth stays. It is examined and radiographed at intervals, and the decision is revisited if anything changes.
What separates them is not preference. It is what the film shows, what the tooth has already done, and what its position makes likely. Two people the same age with the same number of wisdom teeth can correctly be given different recommendations, and the reason is usually visible on their radiographs or in their history.
Outside those situations there is usually time. An impacted wisdom tooth that has been quiet for five years is rarely a tooth that has to be dealt with this month, though that is a judgement made against your film rather than against the calendar. A consultation that ends with you going away to think is a normal outcome.
The three options compared
The table below sets the three side by side on the dimensions that actually differ. Read it against your own film rather than in the abstract — several rows change meaning depending on whether the tooth in question is upper or lower, and whether it is partly through the gum or fully buried.
| Removal | Coronectomy | Monitored retention | |
|---|---|---|---|
| What is done | Crown and roots removed; bone removed and tooth sectioned as required | Crown cut off at or below the bone crest and removed; roots left in place | Nothing removed; tooth examined and radiographed at intervals |
| Where it applies | Upper and lower jaw | Lower jaw only | Upper and lower jaw |
| Usually considered when | Symptoms, decay, repeated pericoronitis, disease on imaging, or damage to the second molar — and the roots are not fixed to the nerve canal | The tooth needs treating, but imaging shows the roots in true contact with the inferior alveolar canal | No symptoms, no disease on imaging, second molar sound, and the tooth is either cleanable or fully covered by bone |
| Effect on pericoronitis | Removes the crown and the gum flap over it, which is where the episodes come from | Removes the same tissue, with the crown | No effect; episodes can recur while the anatomy stays the same |
| Effect on the second molar | Removes the contact point. Decay or bone loss already present is restored by your general dentist, and the findings are sent to them | Removes the contact point. Same caveat | Contact point stays. Decay on the second molar's back surface is watched for on films |
| Lower-jaw nerve exposure | Highest of the three where roots lie on the canal — this is the situation coronectomy exists for | Lower than full removal in the same situation; that is the purpose of the operation. Not eliminated | None from surgery. If removal becomes necessary later, the anatomy is generally less favourable, not more |
| Recovery | Swelling peaks around day two to three; jaw opening restricted for several days; diet widens across the first week | Broadly comparable to removing the same tooth | None |
| What it commits you to afterwards | A post-operative review. Nothing ongoing once healed | Long-term radiographic review of the retained roots | Indefinite review — examination and periodic radiographs, and re-deciding if anything changes |
| Specific things that can go wrong | Altered sensation of lip, chin or tongue; dry socket; infection; bleeding; damage to the second molar or a filling in it. Upper teeth: opening into the sinus, fracture of the bone behind the tooth, displacement of a root | Roots loosen during the crown cut and have to be taken out at the same visit; retained roots migrate; the roots become infected; roots later work their way through the gum and need retrieving | Pericoronitis; decay on either tooth; a cyst forming around an unerupted crown; bone loss behind the second molar; and removal later, when it is often a larger operation |
| If it does not work out | Not reversible. The decision is made once | Retained roots can be retrieved later, usually as a separate procedure | Reversible at any point — that is the argument for it. The trade is that the operation does not get easier with time |
Two rows deserve reading twice. The nerve row is the one that turns coronectomy from an unusual idea into the proportionate operation for a specific group of teeth. The final row is the one that changes the arithmetic: monitoring keeps every option open, but it does not preserve them at today's difficulty. A tooth reviewed from twenty to forty is a different operation at the end of that period than at the start.
What is used to keep you comfortable during removal or coronectomy is agreed at consultation, and depends on the procedure, the number of teeth involved and your medical history. Local anaesthetic is part of every option that involves surgery.
What monitoring actually involves
Monitored retention is a clinical plan, and the parts of it are specific. If a wisdom tooth is being left in place, someone should be able to tell you what is being watched, how, and what finding would change the recommendation.
The clinical part
At each review the things examined are: whether the tooth has moved or erupted further since last time; whether a gum flap has formed over a partly erupted crown, and whether there is a pocket behind it that a brush cannot reach; the gum condition on the back surface of the second molar, measured with a probe rather than judged by eye; whether either tooth has become tender to bite on; and whether the second molar has any decay on the surface facing the wisdom tooth. That last surface is the one that matters most and the one that is hardest to see.
The radiographic part
A panoramic radiograph is the usual film for third molars, because it shows both jaws, all four teeth and the relationship of the lower roots to the nerve canal in one image. What is compared between films is the width of the space around an unerupted crown, whether the bone level behind the second molar has changed, whether the root of the second molar shows any scooped-out defect where the wisdom tooth presses against it, and whether the tooth itself has shifted.
There is no fixed interval that applies to everyone. The interval is set against what is being watched rather than by the calendar: a fully buried tooth with a normal-looking follicle and a sound neighbour is reviewed less often than a partly erupted tooth with a pocket behind it. A monitoring plan also has to name who is doing the reviewing — this practice, your general dentist, or both with the findings passed between them — and that is settled at the consultation rather than assumed. Every radiograph has to answer a question worth the exposure, and it is reasonable to ask what question a proposed film is expected to answer.
What ends a monitoring plan
- A first episode of pericoronitis — swelling, soreness and a bad taste around a partly erupted lower tooth. Recurrence after a first episode is common, because the anatomy that caused it has not changed.
- Decay appearing on either tooth, particularly on the back surface of the second molar.
- The space around an unerupted crown widening between films, or a defined lesion appearing.
- Any sign that the second molar's root is being resorbed by the tooth behind it.
- Bone loss behind the second molar that was not there before.
- A change in your medical circumstances that makes elective surgery either more urgent or less advisable — covered further below.
What tips the decision towards treating the tooth
Several findings carry most of the weight. They are described here as they present in the chair, then set out in a table showing which way each one points.
Pericoronitis, and particularly a second episode
Pericoronitis is inflammation — and often infection — of the gum lying over a partly erupted tooth. A flap of tissue sits across the crown with a pocket underneath it that nothing can clean, and bacteria collect there. It presents as soreness at the back of the jaw, swelling of the gum, a foul taste, and sometimes limited opening. It tends to recur, because the anatomy that produced it does not change on its own. One episode is information. Two episodes is usually the point at which the tooth is treated rather than monitored. An episode that arrives with facial swelling, fever, or difficulty opening or swallowing is not a monitoring question at all — it is on the same-day list in the warning above.
Decay and resorption on the second molar
Where a lower wisdom tooth tips forwards into the second molar, the point at which the two touch sits below the gum line, where no brush and no floss reaches. Decay on that surface is difficult to reach with a drill and difficult to restore well, which is how a healthy tooth ends up needing treatment because of its neighbour. Less commonly, the wisdom tooth presses hard enough against the second molar's root to resorb it — the root is worn away from the outside. That process is not painful, shows on a radiograph as a scooped-out defect, and is usually found while looking at something else. It is uncommon, and most impacted wisdom teeth never cause it. Where it does happen, removing the wisdom tooth usually halts it, though not always, and the second molar still needs following on films afterwards. Root structure already lost does not regenerate.
Findings on imaging
The follicle — the sac around an unerupted crown — has a normal appearance and a normal width. Where that space is wider than expected, or widens between two films, it is investigated, because a follicle can enlarge into a cyst that hollows out bone without producing symptoms. Where imaging shows a lesion needing more than the removal of the tooth it surrounds, that sits outside the surgical scope here, which is third molars, and you are referred on for it.
| Factor | Points towards monitoring | Points towards removal or coronectomy |
|---|---|---|
| Symptoms | None, and none previously | Pericoronitis — especially a second episode; pain on biting; recurrent swelling around the tooth |
| Cleanability | Fully covered by bone, or fully erupted and brushable | Partly erupted, with a pocket behind the crown that no brush reaches |
| Second molar | Sound; no contact below the gum line; no bone loss on films | Decay on its back surface, resorption of its root, or bone loss behind it |
| Imaging findings | Normal follicle, stable between films | Widening follicular space, a defined lesion, or resorption of the neighbour |
| Nerve proximity (lower jaw) | Roots in confirmed contact with the canal and no disease present — raises the threshold for operating at all | The same finding with disease present — which usually points to coronectomy rather than full removal |
| Age | Later decades, where the tooth has already stayed quiet for many years | Late teens to twenties, where roots are often incomplete and recovery is generally quicker |
| Medical history | Anticoagulation, bone-modifying medication or immunosuppression, each of which raises the bar for elective surgery | Planned cardiac surgery, transplantation, head and neck radiotherapy, or starting a bone-modifying drug — where a doubtful tooth is commonly dealt with beforehand |
| Your own circumstances | Willing and able to attend reviews indefinitely, and to accept surgery later if it becomes necessary | Moving away from regular dental care, or unwilling to attend open-ended reviews |
No single row decides it. A tooth with roots on the nerve canal and no disease at all sits in the monitoring column twice over. The same tooth with a second episode of pericoronitis has one row pulling hard the other way, and the conversation becomes coronectomy versus removal rather than treatment versus review.
The nerve, and what it changes
In the lower jaw the constraint that governs everything is the inferior alveolar nerve. It runs in a bony canal beneath the roots of the back teeth and supplies feeling to the lower lip and chin on that side. It is a sensory nerve only: injury to it does not affect the movement of the lip or the face. Separately, the lingual nerve runs in the soft tissue on the tongue side of the lower wisdom tooth and supplies sensation and taste to that side of the tongue. Its position varies between people, and in some it lies at or above the crest of the bone.
A panoramic radiograph shows the canal and the roots as flat shadows overlapping one another, which cannot by itself distinguish a root lying beside the canal from a root wrapped around it. Certain appearances on a panoramic film — darkening of the root where it crosses the canal, interruption of the white lines marking the canal, diversion or narrowing of the canal, and deflection or narrowing of the root — were described by Rood and Shehab in 1990 as indicating a close relationship, and that list is still in common use. Where they appear, a cone-beam scan is considered, and taken where the answer would change what is done.
What the scan does and does not do is worth being clear about. It shows which side of the roots the canal runs on, whether there is bone between the two, and whether the tooth should be sectioned differently or approached as a coronectomy — any of which can change the operation. Whether taking the scan reduces the rate of permanent nerve injury is a separate question and a less settled one. The scan is taken because a decision depends on it.
Temporary altered sensation of the lip and chin after lower wisdom tooth surgery is uncommon, and it becomes more likely where a scan confirms the roots are in true contact with the canal — which is why those cases are consented differently and why coronectomy is discussed for them. Where sensation does recover, that generally happens over the first weeks to months. Permanent alteration is rare. It is also a real outcome, and it belongs in the consent conversation for any lower third molar, stated against your own film rather than as a general caution.
Coronectomy: what it is and who it suits
Coronectomy means removing the crown of a lower wisdom tooth and deliberately leaving the root structure in the jaw. The crown is sectioned off at or below the crest of the bone, taken out, and the socket closed over the remaining roots. The indication for it is narrow: roots that a scan shows to be genuinely bound to the inferior alveolar canal, where removing them would mean working directly on the canal.
It takes away the part of the tooth responsible for pericoronitis and for decay on the second molar next to it, and leaves behind the part that lies against the canal. It is a considered choice against a specific scan, not a compromise or a shortcut.
When it is not appropriate
- The tooth is mobile. A loose tooth cannot have its roots left in place, because they will not stay stable.
- There is active infection involving the roots themselves, rather than the gum over the crown.
- Decay extends down into the root structure that would be retained.
- The tooth lies horizontally in a position where the sectioning cut would have to pass through the roots rather than above them.
- The roots are not in fact close to the canal, in which case the indication does not exist.
What can happen afterwards
Three things are worth knowing before agreeing to it. First, roots can loosen during the crown cut — the tooth is being divided while attached — and if they become mobile they have to be removed at that visit, which converts the procedure into a full removal with the nerve exposure that was being avoided. That possibility is part of the consent, because it means you are consenting to both operations.
Second, retained roots generally migrate away from the canal over the following year or two as bone forms beneath them. In a minority of cases they migrate far enough to reach the gum, or become symptomatic, and are then retrieved as a second procedure — which by that stage is often a simpler operation than the original one would have been, because the roots have moved away from the nerve.
Third, the roots can become infected, which is uncommon and is managed when it happens. Coronectomy therefore commits you to long-term radiographic review in a way that full removal does not. A patient who will not attend those reviews is not a good candidate for it, and that is a reasonable thing to say out loud at the consultation.
Age, and why timing is part of the decision
Wisdom tooth roots are typically incomplete through the late teens and finish forming somewhere in the early twenties. A tooth with short, partly formed roots sits further from the nerve canal, comes out through a smaller opening, and generally involves a shorter recovery. The same tooth two decades later has fully formed roots, often curved, and generally takes longer to remove. It is the same diagnosis and a different operation.
There is a second age effect that runs specifically through the second molar. Removing a deeply positioned lower wisdom tooth can leave a periodontal defect — a pocket with reduced bone — on the back surface of the second molar, and the tendency for that defect to persist rather than fill in appears to rise with age and with how deep the wisdom tooth sat. That is an argument for acting earlier if a tooth is going to be treated at all, and it is not an argument for treating a tooth that does not need it.
The counter-argument is real and belongs in the same conversation. A wisdom tooth that has produced no symptoms and shown no disease into the forties has demonstrated something that a tooth at nineteen has not: that it can sit where it is without causing trouble. Operating on it means accepting a definite set of surgical risks today to prevent a set of problems that, for that particular tooth, have already failed to appear over two decades. The clock argument cuts both ways, and which way it cuts depends on how much of it has already run.
Medical history that changes the answer
Medical history moves this decision in both directions, and it is the part of the assessment most often skipped when the question is framed as a simple yes or no about the tooth.
Reasons to raise the threshold for elective surgery
Anticoagulant and antiplatelet medication does not usually prevent a wisdom tooth being removed, but it changes the planning and the aftercare, and it makes an unnecessary operation less attractive. Do not stop any of it on your own account before an appointment — that decision belongs with the doctor who prescribed it. Bone-modifying medication — bisphosphonates and related antiresorptive and antiangiogenic drugs, whether taken for osteoporosis or as part of cancer treatment — is associated with medication-related osteonecrosis of the jaw following extraction, and extracting a tooth that did not need extracting in a patient taking one of these is a poor trade. Immunosuppression, poorly controlled diabetes and current chemotherapy all affect healing and the response to any infection that follows.
Reasons to treat a tooth that would otherwise be watched
The mirror image applies where treatment is planned that will make a later dental infection considerably harder to manage. Dental assessment and clearance of doubtful teeth before cardiac valve surgery, before organ transplantation, before starting a bone-modifying drug, and before radiotherapy to the head and neck are all common, and a marginal wisdom tooth that would otherwise be monitored is often dealt with in that window. Pregnancy shifts timing rather than the decision itself, with elective surgery generally deferred and urgent problems treated when they arise.
Bring an accurate list of everything you take — prescribed medication, anything bought over the counter, and supplements — to the consultation rather than to the surgery. A medication issue found on the morning of an appointment usually means rescheduling. A previous complication under anaesthesia, in yourself or a close relative, belongs on the same list.
What published guidance says
National guidance genuinely differs on this question. The disagreement is narrower than it first looks, and knowing where it sits makes a recommendation easier to weigh.
In the United Kingdom, NICE guidance issued in 2000 advises against the routine removal of impacted third molars that show no associated disease, and lists the conditions — recurrent pericoronitis, decay, cysts, resorption of the neighbouring tooth, and others — under which removal is indicated. It is a restrictive position and it has been in place for a long time.
In the United States, the position reflected in the American Association of Oral and Maxillofacial Surgeons' white paper on third molar management is less restrictive, and rests on a distinction worth taking seriously: symptom-free is not the same as disease-free. A tooth producing no complaints can still be showing early periodontal changes behind the second molar, or decay, on examination and films. The argument is that a retained third molar carries an ongoing burden of surveillance and an accumulating chance of eventual disease, and that this belongs in the comparison alongside the surgical risk of removing it.
The Cochrane systematic review comparing surgical removal with retention of asymptomatic, impacted wisdom teeth showing no disease concluded that there is insufficient evidence to determine which produces better outcomes, and noted that the available trials were few, small and short relative to the decades over which the question actually plays out. That is not a reason to disregard the question. It is the reason the decision is made tooth by tooth against a specific film and a specific history rather than by rule.
Questions worth asking about your own teeth
A recommendation about a wisdom tooth should be traceable to something on a film or something in your history. These questions pull that reasoning into the open, and each of them has a specific answer.
- What exactly is the finding on my radiograph that leads to this recommendation? Point to it.
- Is this tooth causing disease now, or is the recommendation based on what it might do later?
- Do the roots of my lower wisdom teeth appear related to the nerve canal on the panoramic film, and does that finding warrant a three-dimensional scan?
- Is coronectomy an option for this tooth? If not, which of the reasons it can be unsuitable applies to me?
- If I choose to monitor instead, what specifically are you watching for, how often would I be examined, how often would a radiograph be taken, and who does those reviews?
- What finding would change the plan from monitoring to treatment?
- What is the state of the second molar behind — any decay on its back surface, any bone loss, any sign of resorption?
- If I do nothing for ten years, what is the realistic range of what happens to this tooth?
- Which of my medications or medical conditions affects this decision, and in which direction?
- Is there a clinical reason not to take time to think about it, or to seek a second opinion?
At a consultation here, the findings are shown to you on screen against your own images, with the anatomy pointed out rather than described in the abstract. The options set out always include not operating, and monitored retention is presented with the review schedule it would actually involve and with whoever would carry it out named. Where a tooth should come out, the reason is stated against the film. Where it should not, that is stated too.
This article is general information about third molars. It is not a diagnosis or treatment advice for any individual, and it is not a substitute for examination and radiographs. If you have symptoms, arrange to be seen.