General and dental pathology with special reference to etiology and pathologic anatomy; a treatise for students and practitioners . e deposition ofa new layer not beginning until the previous one is completelycalcined. These layers, or lamellae, are distinguishable under lowand high amplifications and represent the incremental lines ofthe cementum (Figs. 102 and 103). Within its substances arefound the lacunae or spaces containing active cells from the follic-ular wall—the ccmcntoblasts, which became encapsulated duringthe calcification process. From the lacuna? a considerable 234 DENTAL
General and dental pathology with special reference to etiology and pathologic anatomy; a treatise for students and practitioners . e deposition ofa new layer not beginning until the previous one is completelycalcined. These layers, or lamellae, are distinguishable under lowand high amplifications and represent the incremental lines ofthe cementum (Figs. 102 and 103). Within its substances arefound the lacunae or spaces containing active cells from the follic-ular wall—the ccmcntoblasts, which became encapsulated duringthe calcification process. From the lacuna? a considerable 234 DENTAL PATHOLOGY ber of small canals lead out, and these communicate with similarsmall canals from other lacuna?. These small canals are thecanaliculi and they, as well as the lacunce, as has been stated, are inhealthy eementum filled with protoplasmic matter (Fig. 104). The matrix is granular in some locations and fibrous in decalcified specimens in which the organic portion of the ee-mentum is adherent to the dentin, the fibrous character of the ma-trix is plainly visible in some localities. As the eementum calcifies,. r -fi m Fig. 102.—Transverse ground section at the apical region of a root. In the apicalregion and in root bifurcations and trifurcations the eementum is the thickest. Thelamellae or layers of eementum may here be seen especially at a; the dentin at b; andthe root canal at c. through the agency of the eementoblasts in the peridental-mem-brane-to-be, some of the fibers of the latter tissue in its em-bryonic stage become encased in the eementum (Fig. 105). Theyare to be found, as seen in Fig. 105, not in proximity to thegranular layer, but at some distance therefrom in eementum ratheryounger in development. The similarity in development betweeneementum and subperiosteal bone lends credence to our beliefthat the fibrous appearance of the eementum matrix is due to I \ DENTIN, Wl> CEMENTU \l 235 the deposition of inorganic salts in a fibrous frame
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectpathology, bookyear19
