The bifurcated inferior alveolar nerve (IAN)
Bifurcation of the inferior alveolar nerve is a common anatomical variance but can be difficult to detect.
How common is a bifurcated IAN?
It most likely occurs between 13-37%, which you can find in Yoon Gen Dent 2018. This is a wide range and there is almost certainly going to be regional genetic variation making the number trickier to pin down. The main point of these numbers is to know it exists in fairly high numbers. However, most dentists are not familiar with bifuraction of the IAN because we don’t see them. That is fine because often we don’t have a care or need to look for it. Studies show that less than 1% of the bifurcations will show up on a pano. So similar to the mandibular incisive canal, the better equipment we have the and the better we are at looking for it, the more we find.
When does a bifurcation of the inferior alveolar nerve matter?
A bifurcation could be the reason a patient is difficult to numb even though the IAN block is successful. Essentially you would need to have 2 successful IAN blocks to fully numb. To learn a few other tricks on those hard to numb patients check out the end of our blog on anesthetics.
Knowing the anatomy of the IAN is also be important in dental implant placement because damage to either branch would cause issues.