Locating MB2 canal in the maxillary molar

For the success of root canal treatment it is important to locate all canals, do proper instrumentation and obturate. Locating MB2 canals in the maxillary molars is a tricky process, but not so difficult if a specific strategy is followed.

Variation in the location of MB2

It is important to understand that the MB2 may be very close to the MB1, or may be away by 1 to 3 mm. Have a look at these:

Where is the MB2?

Proper access preparation is important. Remove the pulp chamber roof completely. Imagine a line from the palatal canal to the MB1 orifice. MB2 will always be placed mesial to this line, but it may be somewhere within the oval seen here:

Sometimes there will be a dentin lip covering the MB2 orifice. Take your endodontic explorer and scrape in this oval area to remove it if present.

Insert the file into the MB1 canal. Slowly retract it to just out of the orifice, move it mesial to the line connecting palatal canal and the MB1. Change its direction from mesiobuccal to mesial and gently poke around in the oval area that you saw. When it enters the MB2 orifice, release your fingers from around the file, but keeping them in the same position, without touching the file. This gives you the exact direction of the canal. Now slowly go deeper.