Figure 2: Decreased mineral density of teeth, loss of the alveolar bone in the furcation region, and abnormal tooth structures in the Mmp9−/− mice.
From: Dentin Sialoprotein is a Novel Substrate of Matrix Metalloproteinase 9 in vitro and in vivo
(A–F) Representative radiographs show an overall reduction of the mineralization of the molars (arrowheads) and loss of the alveolar bone in the furcation region (arrows) of the Mmp9−/− mice. (G,G’,H,H’) SEM analysis showed the presence of abnormal fissure on the surface of the Mmp9−/− molars. (I–L) The dentin tubules (arrowheads) and the intertubular dentins were well-distributed in the wild-type mice, but in the Mmp9−/− mice the distribution of the dentine tubules (arrowheads) and the intertubular dentins were not uniform with decreased number of dentin tubules and numerous “holes” (*) in the intertubular dentins. K and L are higher magnifications of the rectangles in (I and J), respectively. (M,N) Inversion T2 relaxation time spectra for the first mandibular molars of the wild-type and the Mmp9−/− mice at M1.5 and M2.5. The lines with “dots” are for the Mmp9−/− molars and the lines with “triangles” are for the wild-type molars. Longer T2 relaxation time and larger area under the curve was found in the Mmp9−/− molars. The longer T2 relaxation time is corresponding to larger pores, and the larger area is corresponding to larger porosity (larger amount of holes). WT, wild-type. Scale bars: (A–J) 500 μm, (K,L) 250 μm, (K’,L’) 20 μm, (M-P) 5 μm.
