Dental cosmos . iculum, become solidified into basis-sub-stance, and immediately infiltrated with lime-salts. They claimalso that the enamel-rods are built up by rows of such calcified orpetrified medullary corpuscles, the successive arrangement ofwhich into rows causes the more or less regular appearance of thetransverse strise of Retzius, whereas between the rows longitudinalinterstices will remain, filled, perhaps, with a small amount of cement- 756 THE DENTAL COSMOS. substance, differing in its chemical constitution from the basis-sub-stance of the rods proper, and in its interior holding
Dental cosmos . iculum, become solidified into basis-sub-stance, and immediately infiltrated with lime-salts. They claimalso that the enamel-rods are built up by rows of such calcified orpetrified medullary corpuscles, the successive arrangement ofwhich into rows causes the more or less regular appearance of thetransverse strise of Retzius, whereas between the rows longitudinalinterstices will remain, filled, perhaps, with a small amount of cement- 756 THE DENTAL COSMOS. substance, differing in its chemical constitution from the basis-sub-stance of the rods proper, and in its interior holding extremelydelicate fibrillse (Bodeckers enamol-fibers) which branch into thetransverse striae. Being satisfied that the views of these gentlemenare correct, I will simply add a new feature, to make those viewsmore symmetrical,—and, as it occurs to me, it is a feature of consid-erable importance: viz., the changes that take place in the amelo-blasts during the process of the formation of enamel (Fig. 2). Fig. First-formed enamel of human foetus, six months.—P. dentine. E, enamel toward the dentine, made upof irregular calcined fields, towaid the periphery of prisms with transverse interruptions. M, medul-lary corpuscles finely granular, from which the enamel-prisms are formed. A, ameloblasts, towardthe enamel breaking up into medullary corpuscles, toward the periphery rebuilt by such , irregular ameloblasts torn from their connection with enamel. F, Fibrous connective tissue, chang-ing to medullary tissue. X 800. The ameloblasts, as just stated, split up into rows of finely granu-lar medullary corpuscles, and consequently are reduced considerablyin their size. In fact, it is difficult to find full-sized ameloblasts atthe summit of the enamel-cap, where the production of enamel ismost active, the same as it is impossible to find full-sized odonto- GROWTH OF ENAMEL. 757 blasts at the summit of the papilla, where the formation of dentineis most active. The mutil
Size: 1451px × 1723px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthor, bookcentury1800, bookdecade1880, booksubjectdentistry
