Fig. 3

TEM analysis of internal section of discs of TMJs with or without inflammation. a–c Representative cross-sections of discs from the control group. Collagen fibril diameter ranged from 20 to 120 nm with 40–70 nm noted most often. d–f Representative cross-sections of the discs from the inflamed group. Some large collagen fibrils (d > 120 nm) were observed, and the distribution was heterogeneous. Black arrows indicate abnormal hypertrophic collagen fibrils. g Nonparametric tests of collagen fibril diameter distributions based on three rats per group. The box presents 5%, lower quartile, median, higher quartile and 95%. The black dots represent fibrils count <5% or >95%. Large collagen fibrils appeared after inflammation was induced. The control and inflammation groups exhibited significant differences in collagen diameter. ***P < 0.001, scale bar: 200 nm