I do not think these canals joined in any significant manner. May be some anastomosis of DB and P.
Categories of this blog are
Tooth vital- tooth necrotic
# teeth with MB2 present- able to cleanse and shape the MB2 – MB2 join
MB1 – teeth I consider calcified that no MB2 was found – total # of 2nd
MB2 distance from MB1 – join MB1