highly significantP < 0.001
There was a statistically very highly significant ( P < 0.001) difference of mean gap between Group A and Group B on all four tooth surfaces, being greater in Group A than Group B. 95% CI of the mean difference on the gap in between Group A and Group B ranged within 79.8–147.1 μ on the buccal tooth surface, 62.6–117.3 μ on the distal tooth surface, 88.5–128.6 μ on the lingual surface, and 76.1–115 μ on the mesial surface.