Fig. 3.

Distances of setup errors in all fractions. In each direction, a total of 386 and 183 setup errors in the oral stent (−) and (+) groups are plotted into scatter diagrams. (A) The interfractional setup errors of the x-direction (d_x). The mean distances with standard deviations (SDs) were −0.33 ± 1.63 and −0.37 ± 1.19 mm in the oral stent (−) and (+) groups, respectively (P = 0.499). (B) The interfractional setup errors of the y-direction (d_y). The mean distances with SDs were 0.075 ± 1.97 and 0.24 ± 1.92 mm in the oral stent (−) and (+) groups, respectively (P = 0.645). (C) The interfractional setup errors of the z-direction (d_z). The mean distances with SDs were −0.25 ± 1.79 and −0.63 ± 1.20 mm in the oral stent (−) and (+) groups, respectively (P = 0.009). (D) The interfractional setup errors of the 3D-direction (d_3D). The mean distances with SDs were 2.75 ± 1.53 and 2.42 ± 1.08 mm in the oral stent (−) and (+) groups, respectively (P = 0.022).