Friday 9 December 2011

Crooked teeth? Don't blame wisdom teeth!



There are very few of us lucky enough to have lower front teeth which form a perfect curve.
Most people think that crookedness and overlapping of lower front teeth in their late teens or even early twenties, are the fault of erupting wisdom teeth. If you have had braces done, you may even think that you had a relapse and blame your orthodontist.

Crowded/ crooked lower front teeth

If you think about it, it is not really possible for lower wisdom teeth (which develop slowly in the bone with no firm support) to push fourteen other teeth with roots firmly and vertically implanted in the bone so that the incisors in the middle twist and overlap.
Unfortunately, this is a normal maturation event and affects most people to some extent.  

Wisdom teeth are not so mighty




The lower jaw continues to grow forward after the upper jaw stops growing
How does the lower jaw grow during the late teens?

The lower jaw continues to grow for a while even after the upper jaw stops growing. As the bone grows forward, the lower teeth naturally move forward too. Now the lower front teeth don’t really want to slam into the stationary upper front teeth! Being small and somewhat delicate, they try to avoid a face-off with the big upper front teeth. Commonly, they may compromise by moving or tilting backward. At the same time, the larger lower back teeth have moved forward as well and they cannot go too far back. In their earnest rush to avoid a collision, the well-meaning lower front teeth get crunched for space and have to huddle together in a small space. In fact, sometimes upper front teeth flare out to increase space.


Many scientists consider growth-related changes as having a considerably bigger influence than that of the erupting wisdom teeth on the lack of space present for lower front teeth.  Early extraction of wisdom teeth will not lead to a reduction or solve the problem of lack of space. In the best case it will help to ensure that it doesn’t get worse.







My advice to you:
You may sometimes be told to have your wisdom teeth extracted prior to getting braces. Perhaps you may also be advised to remove wisdom teeth which have not given you any pain and show no sign of causing disease. In this case, remember- your wisdom teeth are innocent until proven guilty! Be sure to discuss in detail with your doctor the reasons why this has been advised, and make an informed decision.





For those with an academic interest:
Lower incisor crowding is multi-factorial and the influence of wisdom teeth on this phenomenon is controversial. Several aspects of bone and soft tissue growth are responsible. I have listed some studies here which debate this topic.
Current controversies in late incisor crowding 
Interventions for treating asymptomatic impacted wisdom teeth in adolescents and adults
The effectiveness and cost-effectiveness of prophylactic removal of wisdom teeth