Graphical representation of the statistical analysis (Kruskal-Wallis test) of differences in the amounts of collagen structures in the hypothetical zones 1 to 4 (Z1–Z4) between the two age groups (‘young’ versus ‘old’).

<p>These pairwise comparisons are displayed as two adjoining boxes. Note: Different designs (orientation of lines) indicate that the differences between the age groups were <i>statistically significant</i>.