Axial view of the first molar on the right side of the maxilla. Straight lines were constructed to connect the various points: the PMB1-PP line and the PMB1-PMB2 line. A third line, PMB2-PT, was drawn to represent a perpendicular line between PMB2 and the PMB1-PP line (PT point). The distance between the points was measured in millimeters using the lines drawn between them.PMB1 - first mesiobuccal canal center; PMB2 - MB2 canal center point; PP - center point of palatal canal; PT - perpendicular center point line between PMB2 and the PMB1-PP lines