Maximum tetanic force. Box and whisker plot showing that (A) radiation treatment was associated with significantly (p<.001) reduced maximum tetanic tongue force during whole nerve stimulation in both age groups, and (B) that age and radiation did not have a significant effect on maximum tetanic force during medial nerve stimulation. Boxes depict the interquartile range (IQR), with a line at the median. Whiskers extend to the last observation within 1.5x the IQR. The closed circles are observations beyond 1.5x the IQR. Y = Young Adult Control; YR = Young Adult Radiated; O = Old Control, OR = Old Radiated.