Here is one more example of a tooth that has an unusual number of canals. The mesial roots (the ones toward the front of the mouth) usually have two canals but this one has a third in the middle. This canal is not obvious to find and is often missed when it is present.
Tooth #30 has previously been accessed and the patient continued to have severe pain.
Here are the MB and ML canals which were already instrumented
Here is a file locating the middle mesial canal. When present this canal usually joins with the adjacent canals but in this case it is an independent canal.
The three canals when they have been cleaned completely.
Final film that shows the 3 independent canals
Three independent canals.
Unusual anatomy in one of the reasons people can continue to have pain with a tooth or problems after having had a previous root canal. An endodontist using a microscope can often find these difficult canals. You can find more information about Bauman Endodontics at www.baumanendo.com