Fig. 2

Box plots of the duration of tooth contact on occlusal surfaces (quadrant 1–4) and on outer surfaces (sextant 1–6) and inner surfaces (sextant 1–6) in N = 59 parents. The line within a box indicates the median, the X the mean value. The upper and lower borders of a box represent the 25 and 75% quartiles. The whiskers represent the highest and lowest values observed within the borders for outlying values (> 1.5 times the box length [i.e., interquartile difference] above and below the upper and lower quartiles, respectively), and the symbols reflect extreme values. Children are taught to brush each quadrant and each sextant for 7.5 s (red line) with their jaws closed when brushing outer surfaces (and thus counting the time for two antagonistic sextants at a time). Accordingly, in this graph tooth contact while brushing with mandibles closed is attributed to both antagonistic sextants in order to match this