You might have heard that wisdom teeth, particularly impacted wisdom teeth, frequently develop into cysts or even tumors, and that therefore, it is a good idea to get them removed for prevention.

Similarly, you might have heard that impacted third molars frequently reabsorb or somehow damage the second molar, and that a preventive removal also makes sense for this reason.

This, my dear reader, is nothing but pure fearmongering. In my opinion, at least, it is pure and nonsensical scaremongering. Remember that I am only sharing my personal opinion here, and that I am not a better dentist than yours, just like Keyblade is not a better rapper than Kanye West.

I am aware that these things can happen. But ever since I began working as a dentist, I have literally never seen a cyst associated to a third molar, and I have never seen an impacted third molar reabsorbing a second molar. I will update this article and others if necessary, but for now, based on my own clinical experience, this is what I can say. These problems seem to be very rare.

Beyond my personal experience, you can also have a look at the Resources, where you will find some clinical guidelines. None of them mention the risk of cysts or reabsorption of the second molar as a valid indication for the removal of healthy and asymptomatic third molars. Even when impacted.

A cyst is defined as a membranous sac or cavity of abnormal character in the body, containing fluid. This can mean a lot of things.

Oral cysts are rare, and in many cases, not particularly concerning. This study in particular mentions that only 5% of the impacted wisdom teeth extracted could be confirmed to have a cyst or a similar condition, such as a benign odontogenic tumor (fear not, these are neither common nor dangerous). To me, even 5% sounds like an exaggerated percentage. Maybe, because the samples were formed by patients that were going to get their wisdom teeth removed, to begin with, which surely inflates the number of abnormalities in the sample. Remember: more fiction has been written in Excel than Word. If we analyzed the general population, including people with impacted wisdom teeth that don’t need to get them removed (which is almost all of them), I am sure that the prevalence of cysts associated to third molars would be much, much lower. I insist: I have never seen a cyst associated to a third molar in real life. And I am a dentist!

In fact, most of the alleged cysts associated to third molars are actually false diagnoses: many dentists will see a little dark area surrounding the crown of an unerupted wisdom tooth, and they will scream: “CYST!!!!!!11”, without a second thought. However, cysts are specific histopathological conditions, and there are multiple types of them: ameloblastomas, keratocysts, odontogenic cysts... Accordingly, they should be removed separately from the tooth and diagnosed under the microscope, not just by looking at an x-ray.

It should also be noticed that cysts can, in many cases, be treated without removing any tooth. It might be possible to enucleate them (removing them directly, without removing any associated tooth) or treat them by marsupialization (cutting them open), depending on the type of cyst and other factors. A cyst might as well be left untreated, depending on the case. And worth noting: not only wisdom teeth can have associated cysts.

Detailed discussions about oral cysts and their management exceed the purpose of this humble project. I am not an expert in oral medicine or cyst management. If you are unlucky enough to have an actual cyst associated to a third molar, I hope you will be able to discuss your options with a respectful maxillofacial surgeon or properly trained dentist.

I invite you to demand a solution as minimally invasive as possible for your problem. Particularly, if your third molar associated to a cyst has enough space, and a favorable position to come in. In that case, its removal should be avoided at all costs. Your surgeon should do any effort necessary to solve the cyst while preserving the wisdom tooth and allowing it to come in.

A child might get an eruption cyst: a little swelling that prevents a baby or adult tooth from coming in. Everybody understands that removing the associated tooth is not reasonable: the proper way to act is by treating the eruption cyst itself (usually by marsupialization, as mentioned above), to allow for the tooth to come in. And wisdom teeth, being teeth like any other, should be considered and treated identically. Dentists exist to solve dental problems, and removing a tooth is the last thing we should do.

I am not here to talk about cyst management, but if you don’t even have a cyst, then your management should be simple enough for me: don’t get your wisdom teeth removed to prevent cysts. It is illogical, and there is no evidence to support doing that. You will be fine, my dear reader. In fact, don’t get them removed to prevent anything. Remember the general principle: a preventive removal is an unjustified removal. You should get them removed if you have pathology or symptoms associated to them, and that’s it.

Similarly, you should not get your impacted wisdom teeth removed in fear of them reabsorbing or damaging your second molars. This issue is equally rare. I have never seen it in real life, and I will refer you again to the Resources section: no clinical guideline advises to remove impacted wisdom teeth for this reason. If your dentist is suggesting you to get your wisdom teeth removed for this reason, he’s being unnecessarily invasive and proactive, and basically an alarmist.

Yes, I know this can happen, but again, it is not at all common. Why would it be common? It doesn’t even make sense physiologically: teeth are not made to reabsorb anything. In fact, the root reabsorption that baby teeth suffer can even happen in the absence of an adult teeth to replace them. Did you know that?

As I see it, if a second molar gets reabsorbed by an impacted wisdom tooth, some other problem must also be present, because, again, teeth themselves don’t reabsorb anything. My intuition tells me that bruxism may play a role. I have never seen a patient with a reabsorption caused “by” a third molar, so this is pure speculation. But bruxism (grinding or clenching) has been linked to the reabsorption of dental roots in general, so it makes sense. If you have been so unlucky that you actually suffered a root reabsorption linked to an impacted third molar, you may want to pay attention to bruxism, which sometimes goes unnoticed (unlike impacted wisdom teeth on panoramic x-rays, that nobody ever misses).

This problem of “clean reabsorptions” should not be confused with cavities forming between an impacted wisdom tooth and a second molar. This problem is a bit more likely, but completely different from the “clean reabsorption” that the proponents of preventive removals love bringing up, as if it were an everyday problem.

In general, I would still not recommend a removal to prevent cavities in this situation. If you have a risk of cavities, what you need is to improve your hygiene and habits, not getting teeth removed. For further insight, you may want to read this other article, on how a lack of space alone doesn’t justify the removal of wisdom teeth. Or this other, where I talk about the hygiene of wisdom teeth.

And that will be everything for this article. Since the frequency of both cysts and the reabsorption of second molars is overestimated, I will say goodbye by quoting Adrián Díaz Marro, a Spanish analyst and businessman, who said: Quien se invente un embarazo, tarde o temprano, no va a tener más remedio que inventarse un aborto, para que le cuadren las cuentas. Roughly meaning: If you make up a pregnancy, sooner or later, you will have to make up an abortion, so that numbers add up.

Saludos cordales.