Estimating the difficulty of wisdom tooth extractions. -

General guidelines and rules of thumb: Erupted vs. impacted. Tooth position and depth factors. Difficulty by impaction type. | How the expected level of difficulty will affect your extraction procedure.

Root
shape.

Link to third molar extraction difficulty animation.

Position
& Depth

Link to wisdom tooth positioning animation.

How hard will your wisdom tooth extractions be?

Your dentist will have an idea, and it's important that they do.

Long before the day of your procedure, your dentist will have made an evaluation of the level of difficulty they expect to encounter when removing your third molars.

  • Their determination will influence several factors about your surgery, such as how many teeth should be removed per visit, the amount of time needed per procedure, and whether or not a recommendation for some type of sedation might be beneficial for you.

  • Your dentist's evaluation will also determine details about how your treatment is performed.

    That's important because their choosing an appropriate surgical approach initially will help to minimize the chances for complications, both during your procedure and the healing process that follows.

How does a dentist estimate the level of challenge that a patient's wisdom teeth pose?

As we describe on this page, some of the best predictors of case difficulty are the angulation (tilt) of the tooth, it's depth and positioning in the jawbone, and the shape and degree of formation of its roots.

A panoramic dental x-ray.

The most common type of x-ray used to evaluate 3rd molars.

These are all factors that a dentist evaluates on dental x-rays. So if they've shared their pictures of your wisdom teeth with you, the information discussed on this page should give you an idea of the level of challenge they pose.


Factors that influence wisdom tooth extraction difficulty.

1) The tooth's position in the jaw.

Much of the difficulty associated with removing third molars correlates with the way they're situated in their jawbone.

And as you might expect, generally speaking the more normal the alignment of the tooth, and the further through the gums it has pierced, the less involved its extraction, and the healing process that follows, are likely to be.

Based on these parameters, dentists have developed a number of rules of thumb that they can use to estimate the degree of difficulty their patient's 3rd molar extractions will pose.

Rules of thumb.

Erupted vs. impacted teeth.

You can expect that erupted wisdom teeth (those that have penetrated through the gums in normal fashion) will generally be easier to extract than impacted ones (those whose eruption has stalled and are still significantly buried in gum and bone tissue).

Soft-tissue vs. bony impactions.

Soft-tissue impactions (teeth that have pierced through the jawbone substantially but are still covered by gum tissue) are typically less difficult than bony ones (teeth that are still considerably, or even completely, encased in bone).

Related: Graphic - Soft-tissue vs. bony impactions.

 

The shape of the jawbone above an impacted third molar will affect its extraction difficulty.

Animation showing wisdom tooth extraction difficulty as a function of its Pell-Gregory classification.

◀ Front of mouth.|Rear of mouth. ▶

Position in the jawbone.

With lower impacted wisdom teeth, the degree of difficulty associated with the removal of a tooth will be influenced by how far back it lies in the jaw.

If it occupies a position underneath the jawbone's ascending ramus (the portion of the lower jaw that rises up and fits into the jaw joint), a greater amount of bone tissue will need to be removed to access, and ultimately remove, the tooth.

Doing so increases the complexity of the extraction process, and is typically associated with a greater potential for postoperative complications (see next section).

Section references - Koerner

 
Takeaways from this section.

If you're lucky enough to have fully erupted wisdom teeth (teeth that have come all of the way into normal position), their removal may not involve any special considerations at all and instead just be performed as routine extractions.

2) The tooth's angulation.

The tilt of a wisdom tooth in its jawbone will affect the ease with which it can be extracted. Vertical (upright) and mesio-angular (leaning forward) impactions are typically easier to remove than disto-angular (tilted backward) or horizontal (sideways) ones.

Much of this difference is due to the extent of the surgical process required (tissue incision, bone removal). And evidence of the importance of this difference lies in the complication rates reported for each of the different classifications, with disto-angular and horizontal surgeries associated with a higher degree of swelling and reduced mouth opening postoperatively than vertical ones. (Bello)

Related: Graphic and examples - Impacted wisdom tooth classifications according to tooth angulation.

Section references - Bello

Takeaways from this section.

Impacted wisdom teeth that have a pronounced tilt are more likely to need to be sectioned (cut into pieces) when removed.

This technique is used as a way of limiting the size of the wound that needs to be created to extract the tooth. That's a positive factor for the healing process that follows. In extreme cases, sectioning might be the only way of getting a tooth out.

The wisdom tooth's depth is compared to the neighboring 2nd molar.

The depth of the wisdom tooth is compared to the neighboring 2nd molar.

Removing this wisdom tooth can be expected to be of "moderate" difficulty.

3) Tooth depth.

Another method of estimating the difficulty of a third molar extraction is to evaluate the tooth's depth as compared to the adjacent 2nd molar.

When making this calculation (via the use of an x-ray):

  • The 2nd molar's root is imagined in thirds.
  • The point where the dentist's instrument (usually an elevator) will be positioned on the 3rd molar is then identified.

    This point is typically where the tooth's crown (enamel-covered portion) ends and root begins. (The white dot and arrow in our diagram lie at this level.)

  • The correlation of this point and the imaginary 1/3rd divisions of the 2nd molar's root is determined, thus indicating how hard the extraction can be expected to be.

Section references - Hupp

Takeaways from this section.

As you'd expect, the degree of difficulty of the extraction process increases as the depth (and hence the thickness of the bone overlying the wisdom tooth) increases. A primary factor for this relationship is that the deeper a tooth lies, the harder it is to access it.

Additionally, deeply positioned teeth are more likely to be near anatomical obstacles such as nerves or sinuses. If so, the risk for surgical complications involving them elevates the complexity of the extraction process.

4) Root anatomy.

Wisdom teeth have multiple roots (lower ones typically have two, uppers usually three). And there can be quite a bit of variation in the way each of them are shaped.

As examples, in some cases each root will be separate and distinct. With others, one or more may have irregular contours or curvature. It's also possible for a tooth's roots to be fused together (either fully or partially).

As outlined below, each of these anatomical variations will affect the relative ease with which the tooth can be removed.

Rules of thumb.

 

In comparison to a wisdom tooth whose roots are relatively straight, distinct and separate:

The shape of a tooth's roots affects the extraction difficulty.

Extraction difficulty is influenced by the tooth's root form.

  • Teeth whose roots are fused together (either partially or fully), especially if they have fused into a conical shape (like that of a pointed ice cream cone), are typically easier to remove.

    (Erupted teeth that have conically fused roots can be astoundingly easy to extract.)

  • Teeth whose roots are dilacerated (curved) or irregularly shaped can pose a greater challenge to extract. For example, those that have bulbous roots often require a substantial amount of bone trimming before the tooth can be removed.

    In some cases, the direction of the root's curvature may actually facilitate the tooth's removal. However, in cases where that's not the case, the root will be prone to fracture in the region of the bend.

  • Teeth whose roots are just 1/3 to 2/3rds formed typically make for an easier extraction that those whose roots are fully developed. This advantage is due to both shorter root length and the fact that immature roots are generally blunt tipped and therefore rarely fracture.

    Root development is a factor that generally correlates with the age of the person. And therefore influences the ideal timing for a third molar's removal. We discuss this and other age-related issues here: What's the best age to have your wisdom teeth extracted?

Section references - Koerner

5) Additional factors

Other factors discovered on x-rays can also signal a greater degree of difficulty for an extraction. This includes the third's proximity (closeness) to the adjacent second molar. Or signs that suggest that the density of the jawbone is elevated.


What to expect with your third molar extraction.

More so than with any other type of tooth in the mouth, removing wisdom teeth routinely poses an assortment of challenges. And due to the range of variations possible, the way your dentist plans an extraction case will need to vary with each patient, and each tooth.

1) Some wisdom teeth are easy to remove.

You don't have to expect the worst. In the case of a fully erupted 3rd molar (one that has come all of the way into normal position), the extraction process for it may be no more difficult than for any other molar, possibly less.

Reasons.

As compared to the molars in front of them, there's a tendency for wisdom teeth to be slightly smaller, and more likely to have fused roots.

Both of these factors, especially when they occur in combination, can help to make the tooth's removal comparatively less difficult, possibly astonishingly so.

Takeaways from this section.

If you're interested, this page outlines the steps that a dentist takes when performing a routine (simple) extraction. This is the type of process typically used to remove erupted teeth. (Compare to "surgical" extraction, discussed below.)

2) Some wisdom teeth will require "surgical" intervention.

With impacted third molars (those that still lie buried in the jaw), the dentist will of course need to gain access to the tooth before they can remove it. And that means they must perform a "surgical" extraction.

With this process, the surrounding gum tissue is incised and flapped back and, if needed, bone tissue is trimmed away, so the dentist can visualize and manipulate the tooth. (The link above provides more details.)

Takeaways from this section.

There's no need to be overly apprehensive about the need to have a surgical extraction.

When deemed necessary, this approach typically allows the extraction process to be performed more predictably, quickly and smoothly. That's a big positive for both your in-office procedure and the healing process that follows, thus allowing your entire experience overall to be less eventful.

Sectioning a 3rd molar during extraction.

Less bone removal is needed when a tooth is "sectioned" into parts.

3) Sectioning wisdom teeth.

A dentist may be able to minimize the amount of bone tissue that must be removed during the extraction of a third molar by cutting the tooth into pieces.

Since each individual part is smaller than the tooth as a whole, they can be removed through a smaller access opening. This procedure is termed "sectioning" a tooth.

 

C) How extraction difficulty can affect patient aftercare and the post-extraction healing process.

In general, the quicker and easier it's been for the dentist to access and remove a wisdom tooth, the less tissue trauma that's created and the more uneventful the extraction site's healing process should be.

 

As examples:

  • The post-operative inconvenience and aftercare needs associated with the routine extraction of an easily accessed, fully-erupted third molar may be surprisingly minimal, to almost non-existent.
  • At the other extreme, the swelling and pain resulting from a difficult impaction may require several days of recuperation.

Which scenario applies to you will simply depend on how difficult (traumatic) your extraction process has been. And thanks to the type of indicators discussed on this page, your dentist should be able to give you an idea of what to expect even before your procedure is performed.

Aftercare guidelines and instructions.

For the most part, extraction aftercare is broken into two general time frames:

When it comes to preventing or minimizing post-operative complications, nothing is more important than following your dentist's instructions, period. (Use the links above for more information.)

 
 
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Comments

Thank you.

My son is about to have a wisdom tooth, which is at his gum line pulled. I am so nervous. This posting really helped me understand what is going on. I wish I had such a source years ago when I went through this.

Roger

You mention that it's your "son" - Implying a person of youngish age. Generally speaking age is a factor that favors experiencing an uneventful wisdom tooth extraction process.

You also mention that the procedure will happen fairly soon, as in possibly you are using the holiday as the recuperation period which makes a good plan just in case he needs an extended recovery period (like in the case where there is post-op swelling that needs to come down).

And you also mention that the tooth is "at his gum line." That implies a partially erupted wisdom tooth. The kind are the most troublesome to maintain and therefore make good candidates for extraction.

Sounds like you are doing everything right. Good luck with your son's procedure.

Horizontal wisdom tooth removal

Hi,

Tomorrow I am scheduled for the surgery required to remove my horizontally grew wisdom tooth (down, right). I am 27 years old. At the 3d scan I took 2 days ago it showed that the roots of the tooth are ‘hooked’ to the nerve and the doctor had said that there are chances in the moment they will pull the tooth out for the nerve to be damaged. I will experience numbness for hours, or days, or weeks, or months or it the nerve will never fully recover and the numbness will stick forever. We won’t know until it is done..
i am quite concerned and I am trying to make a list of questions to ask the doctor before the surgery. Maybe you could give me some ideas, please.
Thank you!

Ana

Good luck tomorrow.

We'd like to think that possibly what your dentist has stated is simply very thorough "informed consent" information, to the point of overstating what they actually anticipate is most likely to happen. Hopefully your actual level of risk is substantially less than what you currently imagine.
--
Where the potential for complications with paresthesia are comparatively higher, we would make sure we were in the most capable hands possible, meaning an oral surgeon as opposed to a general dentist.

Based on your mention of a "3d scan" (a type of imaging that most general dentists don't have in their office), we're assuming you have that issue covered.
--
There should be clear reasons why the tooth needs to be removed, including an explanation of why the issues associated with leaving it exceeds the expected risk for permanent nerve damage. (We have pages that discuss general reasons why wisdom teeth should be extraced and others that may not be such valid reasons.)

--
In terms of questions to ask about how the procedure will be performed to help prevent nerve trauma from occurring, only your doctor can determine the approach that's best.

For a horizontally positioned tooth, we would imagine some degree of sectioning would be planned for (see above on this page). That would be positive to know because usually that means the tooth can be removed relatively less traumatically.

--
Generally, we would just focus on the fact that the tooth has good reason to be removed. That we are in the hands of a highly trained and skilled practitioner. And that you and they want the exact same thing, the most uneventful extraction process for you possible. Once again, good luck.

Nerve damage

Was wondering if u had any nerve damage? My 17 year old has surgery in 5 hoUrsula and I am so.nervous for him. I have had to have an 8 hour reconstructive surgery due to being punched. Half my face is titanium and the nerves covering 75 percent of that side werected damaged. It took about 5 years to repair itself. Was just wondering your outcome .

Removal of imapcted wisdom tooth

Sir around 1week ago it got extracted. After a short surgery still there is a little sweling n pain n couldn't open mouth fully how long will it take by tommorw mi sutures will be cut

Soni

You should go ahead and contact your dentist's office and report your symptoms. As the only one who knows the specifics of your case, they would be the only one able to give you any sort of specific explanation about what might be expected.

Here's our page about the normal timeline associated with extraction site healing, and then this page covers symptoms encountered during the healing period following your extraction.

Gum closure after wisdom tooth extraction

Hello! I had my lower right wisdom tooth extracted three weeks ago. A week later I went back to the dentist due to dry socket which he treated by an alvogyl dressing. Then another week I went back again for a follow up and the dentist renewed the dressing. The hole in the gum is not closing and I can still see the dressing inside. I rinse my mouth with warm salt water after every meal, 3-4 times a day.
I am still only eating soft food because after eating solid food I feel a slight pain near the extraction site, otherwise I don't feel any pain. I think the gum is slightly swollen on the outer side.
I am just wondering how long the gum will take to close up and whether I should start eating normal food and the pain will go away itself? Can I drink alcohol and whether it will slow down the healing process? If not now, when can I drink? It's just that my daily activities are affected and I wish I could start eating and drinking normally.

A Jady

You need to report to your dentist so they can evaluate your situation.

The alvogyl is usually placed on a dressing, that may or may not be a material that dissolves away on its own. If not, it must be removed. If it is, and now a week later you still see some type of object in your socket, the situation should be evaluated by your dentist. The presence of alvogyl in the socket beyond the time frame it is needed will delay healing. Here's our page about dry socket dressings.

The hole itself will fill up from the bottom, as opposed to initially closing over at the top, so it's expected that you'll may see some remnant of a hole for quite some time.

In regard to a routine extraction, at a point 3 weeks later, the moderate consumption of alcohol would typically be a non-issue. If you are taking any type of narcotic pain reliever, or even types of antibiotics, its consumption would instead be contraindicated. In your situation, with the complications you state, you should discuss the issue with your dentist.

Hi there

Hi there
I’m having my upper right wisdom tooth removed next week and it is partly erupted and angled towards the neighboring tooth. It has slight decay because of the angle it made it hard to brush properly. My dentist said it doesn’t seem to difficult but the oral surgeon will see on the day. The only problem is that the root is long and touches my sinus. How difficult are those type of extractions usually? I’m 31 years old by the way.
Thanks in advance.

Anonymous

As opposed to tooth length, probably the larger factor associated with extraction ease is the configuration of the tooth's root's. If you've seen your x-ray, maybe your dentist mentioned if the roots were all separate like a tripod, or at the other extreme, fused together like a pointed ice cream cone.

With the latter, the extraction is often astoundingly simple. If the roots are separate, they simply offer more resistance form in regard to the tooth being removed.

Probably most on your dentist's mind is the thickness of the bone in the region where your tooth approximates the sinus (it may just be paper thin).

When an extraction is a struggle, it's possible that the tooth might push through the bone into the sinus (it's unlikely that an oral surgeon will let this occur). Or the thin bone may fracture and create an opening into the sinus (if this occurs, an oral surgeon will know how to close the wound so healing occurs uneventfully).

It seems your dentist has your best interest in mind. They see the potential for problems, and have referred you to an oral surgeon whose knowledge and skill will make it much less likely that any problem will occur.

Wisdom tooth extraction question

Hi, I would like to know if it is true that when, the upper right wisdom tooth is extracted the lower right wisdom tooth NEED to be extracted too? This is what my dentist says.

Please let me know. Thank you!

Valerie

Both teeth are completely separate entities, so no, with just routine cases there are no reasons why both absolutely have to be extracted. There can, however, be a myriad of reasons why doing so may make the better/right choice.

One would have to imagine that without an upper wisdom tooth to chew against, your dentist envisions a situation where the benefit vs. risk potential associated with the lower wisdom tooth (either now or sometime in the future) makes removing it the better plan.

You should simply ask them what concerns they have. And why extracting the tooth now makes the best approach. It should be simple enough for them to provide you with an answer.


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