Wisdom Teeth
 

How does the Dentist Diagnose my Problem?

The dentist needs to confirm that the problem is actually your wisdom tooth or teeth and rule out that the pain is coming from any other source such gum problems, problems with surrounding teeth or TMJD. This is the purpose of the dental consultation. 'How does the dentist diagnose my problems?' in the dental extraction series will give you some good information on this.

How are my Wisdom Teeth Assessed?

As with most things in dentistry, your wisdom teeth will be assessed clinically and radio graphically, meaning the dentist will look at them directly in your mouth and then study an X-ray. Both provide information and are used together to paint an accurate picture of the full situation.

They will want to see and check the following:

  • Level of eruption. Whether the wisdom tooth is fully erupted, partially erupted (just poking its head through) or un-erupted.
  • The angle. Is the wisdom tooth is visible and what angle it is at? Is there any chance it may come through fully and be useful? Is food getting packed next to it? Is the cheek or gum being traumatized?
  • The position of the wisdom tooth- is it in line with the others or is it out to one side?
  • Signs of infection. Is there any evidence of infection such as tenderness, swelling, redness, discharge of pus?
  • Signs of decay. Are there any signs of decay in the wisdom tooth or the number seven tooth next door?
  • Opposing tooth. What about the opposing tooth- is it there? Has it been removed?


Are X-rays necessary?

A good clear X-ray of the wisdom tooth or teeth is almost always required as part of the assessment. This is normally an OPG view, though sometimes a Peri- Apical X-ray will be used if you have a particular problem with one of your wisdom teeth.

There is much important information to note on the X-ray, when assessing for extraction

When considering wisdom teeth extractions specifically, one of the most critical questions is how close the Inferior Dental (ID) nerve runs to the roots of your wisdom tooth. This only applies to the lower teeth.

Just because it looks close doesn’t actually mean it is; the OPG is a 2D picture of a 3D structure, so this must be appreciated.

Evidence that there is a close relationship is indicated by:

  • A darkening of the root
  • A detour of the canal around the root
  • A break in the thin white line of the canal (cortical bone surrounding the nerve)
  • The nerve passing in-between the roots (rare but in these circumstances the risk of damage is very high).

In these circumstances, it can sometimes be advisable to get a 3D image in the form of a CAT scan to assess more precisely the route of the nerve and the potential risk of damage.

Because of the dose of radiation associated with this, it is reserved for those times where it will provide useful information about how best to approach the extraction procedure for your wisdom tooth.

We discuss nerve damage and wisdom teeth more in the risks and complications section.

Will the Extraction be Difficult?

The difficulty of the extraction will depend on the factors discussed generally in ‘Dental Extractions’. Remember, what may be difficult for one dentist, may be considered more routine for a dentist who has more experience in that type of procedure or for a specialist oral surgeon.

Specifically in relation to wisdom teeth, the difficulty depends on a combination of these factors:

  • If it is un-erupted or erupted. Wisdom Teeth that are largely through or just have some gum sitting over the top of them are considerably easier to remove. The more bone that must be removed in order to expose and remove the tooth, the more difficult the extraction will be. That is why I will sometimes say ,'If it is not causing you that much pain and isn’t infected, let’s allow it to come through a little more to make things easier.' If you are going to need all four wisdom teeth out anyway under general anaesthetic- waiting doesn’t really have any benefit.

  • The angle of impaction. A tooth can be impacted in different ways:

(i) Horizontally (3%)- meaning totally on its side, pointing at the roots of the second molar.

(ii) Vertically (38%)-meaning upright but with bone over the top (i.e. un-erupted).

(iii) Mesio-angular(44%)- meaning leaning forward towards your second molar.

(iv) Disto-angular (6%)- leaning backwards away from your second molar. These may look fairly
straightforward, but removing bone at the back of these teeth can be particularly difficult.

  • The level of impaction. The further down in your jaw that your tooth is, the tougher it will be.

  • Access. How far back the wisdom tooth is and how wide you can open, will affect how easy it is for the dentist to see what’s going on and how easy it will be to remove the tooth.

  • Size of the tooth/number of roots- their shape, length… are they are curved, bulbous, or fused together? Looking at the extremes; a nicely shaped, single fused conical root will be considerably easier than a wisdom tooth with 3 separate roots that are severely curved.

  • ID canal. How close the roots of the wisdom lie to the ID nerve. See the evidence for a close relationship in the section above.

  • Tooth condition. If the wisdom tooth is very decayed and broken down, then getting a good grip can be more difficult.

  • Is the tooth loose? One of the things I like to do is put my probe into the tooth and give it a wiggle. If it moves, it suggests the extraction is likely to be easier and it is just a matter of creating enough space to remove it.

  • Age. Wisdom teeth are typically easier to remove in your teens, before the roots have fully formed. At this point the risk of nerve damage increases slightly, since the two are closer together. The younger you are, the more spongy and forgiving your bone is too, so it tends to be easier to expand the socket and pop the tooth out.