Estimating the difficulty of wisdom tooth extractions. -

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.

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.

◀ 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

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

The wisdom tooth's depth 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

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:

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.

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.)

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:

• The first 24 hours after your surgery.
• The time period 24 hours after and beyond.

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.)

Update log -

02/05/2019 - Extensive revision, reference sources and graphic added.

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Topic Menu ▶  Wisdom Teeth (third molars).

• Wisdom teeth basics -
  
  • Which teeth are they? (pictures) | Impaction classifications. (diagrams / pictures)
  • FYI facts about getting your wisdom teeth out.
• Overview of valid reasons for 3rd molar extraction.
  
  • Pain / Tissue trauma / Cysts / Tumors / Root resorption of adjacent tooth.
  • Pericoronitis (infection surrounding a 3rd molar).
  • Other reasons: Tooth decay. / Gum disease.
• Reasons not to extract third molars.
  
  • Do wisdom teeth really need to be removed?
  • The fallacy of the 3rd molar/tooth crowding theory.
  • Using a wait-and-see approach with wisdom teeth.
• Extracting wisdom teeth -
  
  • Estimating surgical difficulty.
  • At what age should you have your surgery performed?
  • Conscious sedation techniques used with oral surgery.
  • Aftercare: First 24 hours. / Day after and beyond.
  • Wisdom tooth extraction costs (according to impaction type).
• Overview of common post-extraction complications.
  
  • Dry Sockets / Paresthesia (nerve damage)
• Related pages -
  
  • Topic: Tooth Extractions