Figure 1. Alcian blue and PAS staining showed an overview of the rat’s temporomandibular joint during natural growth (A: 42 days old) and during mandibular advancement (B: 7 days after the experiment; note the forward positioning of the condyle). Two measurement frames that overlapped at the erosive front in the posterior condyle were used for quantitative analysis (B). In situ hybridization (ISH, C and D, arrows) and immunohistochemical staining (IHC, F and G, arrowheads) showed Runx2 expression in the rat’s condylar cartilage during natural growth (C and F: 49 days old) and mandibular advancement (D and G: 14 days after the experiment). In situ hybridization with sense probe (E) and immunostaining omitting primary antibody (H) served as negative control. Scale bars: 100 µm.