Technique for measuring root canal curvature (schneider method )

 The angle of the curvature was first determined by Schneider (1971). He determined by marking certain points like point A which denotes the apical foramen. The point where the canal begins the curvature is marked as point B. A line is then drawn parallel to the long axis of the canal through point B, and a point C is chosen on this line such that the distance between B and C is equal to that between A and B. The angle formed by lines AB and BC is the angle of curvature.

From E and F, the midpoints of AB and BC, respectively, two lines are drawn perpendicular to the lines AB and BC, which would meet at the circumcentre 0 of triangle ABC. The distance between 0 and A, B or C is the radius (K) of the circumference, which determines the magnitude of the curve.